Complete Molecular Response Research Articles

Dasatinib and CAR-T Cell Therapy for Newly Diagnosed Ph-Positive Acute Lymphoblastic Leukemia in Adults

Introduction The use of tyrosine kinase inhibitors has improved outcomes of Ph-positive Acute lymphoblastic leukemia (ALL), but combinations with other agents are needed to achieve molecular response. CAR-T cell therapy has made a breakthrough in refractory or relapsed ALL, but has not yet been applied in newly diagnosed patients. Methods We conducted a phase 2 single-group trial of first-line therapy in adults with newly diagnosed Ph-positive ALL. Dasatinib in combination with a two-week vincristine and glucocorticoids regimen were administered, followed by sequential infusions of CD19 and CD22 CAR-T cells. All patients received single-agent dasatinib maintenance after CAR-T cell therapy. The primary endpoint was complete molecular response (defined as undetectable BCR/ABL1 transcript with a sensitivity of 0.001%) in the bone marrow after this treatment. Here we report initial results from this study. Results At the cut-off date of 31 May 2023, 18 patients have received CD19 CAR-T cell infusions, and 14 of these patients have received subsequent CD22 CAR-T cell infusions. At the end of induction therapy, the complete hematologic remission rate was 100%, and 27.8% (5/18) of the patients had a complete molecular response. The percentage of complete molecular response increased to 72.2% (13/18) after CD19 CAR-T cell therapy, and increased further to 76.9% (10/13) after CD22 CAR-T cell therapy (1 patient has not been evaluated). Notably, of the 5 patients who did not achieve complete molecular response after CD19 CAR-T cell therapy, 4 have received CD22 CAR-T cell therapy, of which 1 eventually achieved complete molecular response and 2 experienced relapses. One patient had a CD19+ CD22+ relapse accompanied by mutations in BCR/ABL1 (F317L and Y253H) and the other patient had a CD19dim CD22+ relapse. After a median follow-up of 13.5 months, 16 patients remained in complete hematologic remission, and 14 patients remained in sustained complete molecular response. No patient received allogeneic stem cell transplantation. No grade 3 or higher cytokine release syndrome or Immune effector cell-associated neurotoxicity syndrome was observed during CAR-T cell therapies. Conclusions Dasatinib in combination with CAR-T cell therapy has enabled chemotherapy-free treatment in newly diagnosed Ph-positive ALL. This treatment is characterized by high complete molecular response, high long-term survival, low toxicity and short treatment cycles.

Treatment with Daratumumab Plus Bortezomib, Cyclophosphamide, and Dexamethasone May Result in Both Hematologic and Metabolic Complete Response to Achieve Long-Term Progression Free Survival Among Patients Presenting with Extra-Medullary Disease: A European Myeloma Network Study (EMN19)

Introduction: Multiple myeloma (MM) with extramedullary disease (EMD) is an aggressive disease that requires innovative treatment strategies. Methods: The ongoing multinational, open-label phase 2 EMN19 trial (NCT04166565) enrolled patients (pts) with MM and EMD either as newly diagnosed MM (NDMM) or at first relapse (RMM). Pts received Daratumab (Dara) in combination with bortezomib (V), Cyclophosphamide (C), and Dexamethasone (D) (DaraVCD), either until disease progression or for a maximum of 36 months, along with autologous stem cell transplantation. Response to treatment was assessed using both the International Myeloma Working Group (IMWG) and the Impetus criteria for evaluating the EMD responses. Complete metabolic response (CMR) was defined as: Deauville scores 1, 2 or 3, with absence of FDG-avid bone marrow lesion(s), irrespective of a persistent mass on CT, or complete disappearance of EMD. Partial metabolic response as: Deauville score of 4 or 5 with decreased uptake compared to baseline and absence of structural progression development on CT or 50% reduction in EMD size. MRD assessment was performed locally at the time of CR or at an earlier time point, as per clinical practice. Pts without MRD assessment were included in the denominator when estimating the MRD(-) rate. Pts who had discontinued treatment by Cycle 4 were considered as non-responders (both in terms of hematologic and EMD response). Progression-Free Survival (PFS) was analyzed by the Kaplan-Meier method. Cox regression analysis with Firth's correction was used for the estimation of the hazard ratios (HRs) and 95% confidence intervals (CIs). Results: A cohort of 40 pts (73% NDMM; 28% RMM) was enrolled. The mean age was 58 years, with 22 (55%) of the pts being male. At baseline, 33 (83%) of the pts were in stage ≤II of the International Staging System and 6 (15%) were classified as high-risk according to FISH (t(4;14), t(14;16) and/or del17p). Among the pts, 22 (55%) had extramedullary plasmacytomas (PCTs), 14 (35%) had paraosseous involvement, and 4 (10%) had both. The median number of PCTs per pt was 2. At the cut-off date with a median follow-up (FU) of 23 months, 17 (43%) pts were still on treatment, while 23 (58%) had discontinued treatment mainly due to disease progression (13, 33%), inadequate response at the end of cycle 3 (5, 13%) or death (3, 8%). In the overall population, deepest responses were as follows: MRD(-) was achieved by 15 (38%) pts, ≥Complete response (CR) by 18 (45%) pts, ≥VGPR by 30 (75%) pts with an overall response rate (ORR) of 80% (32 pts). The median (range) time to MRD(-) was 19 months (4-33); 13 of the 15 MRD(-) pts were NDMM. Median PFS (24-months PFS rate) was 26 months (56%) in NDMM and 15 months (36%) in RMM. Overall, 28/40 (70%) pts had a concurrent hematologic and EMD response of partial response (PR) or better; the best hematologic responses achieved among those pts were: MRD(-) (15 pts), ≥CR (16 pts), VGPR (10 pts) and PR (2 pts). Additionally, 4/40 pts had a response of ≥PR (1 stringent CR, 1 CR and 2VGPR) without achieving an EMD response, while 8/40 pts had discontinued treatment by cycle 4 and did not have a hematologic or EMD response. The combinations of hematologic and EMD responses for 28 pts with concurrent hematologic and EMD response are shown in Figure 1. As seen in Figure 2, pts with concurrent hematologic CR (hemCR) and CMR had the best outcomes in terms of PFS, while having only one type of response (hematologic or EMD) was associated with inferior outcomes compared to having a response in and outside of marrow (p<0.001 overall and in NDMM). Overall, the respective HRs (95% CI) were: no response vs both types: 20.5 (3.5-119.8), p<0.001; one type vs both types: 8.3 (1.2-58.2), p=0.034. The median (range) time to first concurrent hemCR and CMR was 6 months (3-15); for pts achieving only one type of response (hemCR or CMR) the median (range) time to first response was 5 months (1-11). Conclusions: After a median FU of 23 months of DaraVCD treatment, 33% of the pts have achieved both deep hematological responses with MRD(-) and CMR resulting in a median PFS of 20 months. However, having only one type of response (hemCR or CMR) is associated with an inferior outcome. These results, in terms of response, are comparable to those found in the LYRA study in which NDMM EMD pts are treated using a similar DaraVCD protocol. Even in this high-risk population of unmet need, long-term deep responses can be achieved with DaraVCD in and outside of marrow.

Frontline Combination of 3 rd Generation TKI Olverembatinib and Blinatumomab for Ph+/Ph-like ALL Patients

Background The combination of dasatinib and blinatumomab represented a chemotherapy-free treatment approach, which had been employed in the management of newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL). A recent study demonstrated that combination therapy of ponatinib with blinatumomab may achieve better efficacy, with a complete molecular response (CMR) rate of 87%. However, some patients required dose reduction or even discontinuation of ponatinib for the occurrence of cardiovascular adverse events. Olverembatinib, a potent third-generation tyrosine kinase inhibitor (TKI), showed both favorable tolerability and significant efficacy in patients with TKI-resistant chronic myeloid leukemia. But its effectiveness in ALL remained unaddressed. Our recent study, a frontline combination of Olverembatinib and PDT-ALL-2016 regime in Ph+ALL, had shown a promising outcome, achieving a complete molecular response (CMR) rate of 84.6% at day 90. Herein, we explored the clinical efficacy of the frontline combination of Olverembatinib and blinatumomab for the treatment of Ph+ and ABL-class Ph-like ALL. Methods From April 2022 to May 2023, 13 patients with Ph+/Ph-like ALL treated with olverembatinib (40mg once every other day) and blinatumomab (administered for a total of 2 weeks followed by 2 weeks of break) were enrolled (Figure 1a). Two patients (15.4%, 2/13) were in Ph-like ALL group with TEL-ABL and EBF1-PDGFRB fusion gene. Five patients (38.5%, 5/13), with a median age of 58 years old, were received ≥2 cycles and eight patients (61.5%, 8/13), with a median age of 34.5 years old, were treated with 1 cycle before HSCT. Result With a median follow-up of 7 months, all patients (100%, 13/13) achieved complete remission (CR) after one cycle of treatment. Among them, nine patients (72.7%, 9/13) achieved complete molecular remission (CMR) after one cycle, and ten patients (90.1%, 10/13) after two cycles. Notably, all patients (100%, 13/13) achieved CMR within three months of olverembatinib and blinatumomab treatment (Figure 1b). The 6-month overall survival (OS) rate was 100% and the 6-month event-free survival (EFS) rate was 87.5% (Figure 1 c and d). One patient with ABL mutation EE255V died due to relapse after HSCT. The regimen was overall well tolerated. For hematologic toxicity, one patient (7.7%, 1/13) experienced grade 1 neutrophil decrease. Regarding non-hematologic toxicity, five patients (38.4%, 5/13) developed infections during treatment, including COVID-19 and herpes zoster. Five patients (38.4%, 5/13) experienced decreased levels of immunoglobulins. Ten patients (76.9%, 10/13) experienced grade 1 cytokine release syndrome (CRS). Importantly, there were no interruptions in dosing of olverembatinib during treatment while no cardiovascular adverse events were observed. Conclusion This is the first report on the combination of olverembatinib with blinatumomab for the treatment of Ph+/Ph-like ALL. Among the 13 patients enrolled, a notable rate of CR and CMR was observed, which holds promise for improved long-term survival. Additionally, the combination of olverembatinib and blinatumomab exhibited minimal adverse events, both in terms of hematologic and non-hematologic toxicities. Notably, fewer cardiovascular adverse events that required discontinuation of treatment compared to ponatinib were observed. Altogether, these findings strongly indicated that combination therapy of olverembatinib with blinatumomab has the potential to become a new standard of care in the frontline treatment of Ph+/Ph-like ALL. However, further clinical trials are needed to definitively establish the efficacy of this treatment approach and validate the potential benefits. This research was supported by the National Natural Science Foundation of China(NFSC82170163, 81970147), Clinical Study of Nanfang Hospital(LC2016ZD009/2019CR012).

Glofitamab Plus R-CHOP Induces High Response Rates with a Manageable Safety Profile in Patients with Previously Untreated Diffuse Large B-Cell Lymphoma (DLBCL): A 12-Month Analysis from a Phase Ib Study

Background: Over a third of patients (pts) with DLBCL do not respond or relapse after first-line (1L) treatment with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; Sarkozy and Sehn. Ann Lymphoma 2019); these pts have limited curative options. Glofitamab (Glofit) is a T-cell engaging bispecific antibody with a novel 2:1 (CD20:CD3) format that allows bivalent binding to CD20 on B cells; this enables combination with anti-CD20 antibodies, including rituximab. Glofit monotherapy has shown durable responses in pts with relapsed/refractory DLBCL (Dickinson et al. NEJM 2022). In the safety run-in and expansion phases of the ongoing NP40126 trial (NCT03467373), Glofit + R-CHOP demonstrated promising efficacy and manageable safety in pts with 1L DLBCL (Topp et al. ASH 2022). Here, we report durability of response beyond 12 months in Glofit + R-CHOP-treated pts with 1L DLBCL from the NP40126 trial. Methods: Pts received R-CHOP for 6-8 three-weekly cycles. Intravenous Glofit was given with step-up dosing during Cycle (C)2 (Day [D]8, 2.5mg; D15, 10mg) and at the target dose (30mg) from C3D8 onwards. Glofit maintenance was allowed for up to one year. Efficacy was analyzed in all pts who had been on the study long enough to have a protocol scheduled end-of-treatment response assessment. Safety was analyzed in all pts who received at least one dose of any study drug. Response was assessed by PET-CT using Lugano criteria (Cheson et al. JCO 2014). Cytokine release syndrome (CRS) events were graded using the American Society for Transplantation and Cellular Therapy criteria (Lee et al. Biol Blood Marrow Transplant 2019) and other adverse events (AEs) by the Common Terminology Criteria for Adverse Events (v4.0). Hospitalization was not mandated for Glofit. Results: As of April 4, 2023, 56 pts were enrolled in this cohort. Median age was 68 years (range: 21-84), 54 pts (96.4%) had Ann Arbor stage III/IV disease, and median International Prognostic Index (IPI) score was 3 (IPI 1: 3.6% [2/56], IPI 2: 33.9% [19/56], IPI 3: 35.7% [20/56], IPI 4: 23.2% [13/56], IPI 5: 3.6% [2/56]). The cell of origin was germinal center B-cell (GCB) in 25 (44.6%) pts and non-GCB in 11 (19.6%) pts. After 17.1 (range: 0-26) months of median follow-up, the best overall response rate was 92.9% (52/56) and the complete metabolic response (CMR) rate was 83.9% (47/56). Median time to CMR was 1.8 months (95% confidence interval [CI]: 1.6-4.7). Most CMRs (44/47; 93.6%) were ongoing at data cut-off ( Figure). Among complete responders, the Kaplan-Meier estimated probability of ongoing responses at 12 months was 91.5% (95% CI: 82.2-100). Median duration of response and duration of complete response were not reached at data cut-off. The incidence of AEs and serious AEs (SAEs) were similar compared with earlier analyses. Grade (Gr) ≥3 AEs occurred in 42 (75.0%) pts and Gr ≥3 AEs related to Glofit in 14 (25.0%) pts. SAEs were reported in 20 (35.7%) pts and SAEs related to Glofit in six (10.7%) pts. Gr 5 AEs were reported in four (7.1%) pts (COVID-19 pneumonia, n=3; infusion related reaction associated with rituximab, n=1). AEs leading to dose interruption of Glofit occurred in 12 (21.4%) pts. Median dose intensity was 100% for all R-CHOP components. AEs leading to discontinuation of Glofit occurred in one (1.8%) patient. CRS events were reported in six (10.7%) pts: Gr 1, n=4; Gr 2, n=2; no Gr 3/4 CRS events were reported. All CRS events occurred during C2-3. Tocilizumab was used in two (33.3%) pts with CRS. Neurologic AEs (NAEs) occurred in 23 (41.1%) pts (most common NAEs (>5%) were peripheral neuropathy, n=7 [12.5%]; paraesthesia, n=5 [8.9%]; insomnia, n=4 [7.1%]; headache, n=3 [5.4%]); Gr 3 NAEs included cerebrovascular accident (n=1) and herpes zoster (n=1). No Glofit-related NAEs consistent with immune effector cell-associated neurotoxicity syndrome were reported. Neutropenia was reported in 26 (46.4%) pts (Gr ≥3 neutropenia: Gr 3, n=5; Gr 4, n=19). Infections and infestations were reported in 27 (48.2%) pts (of which the majority were Gr ≤2 [17/27]); Gr 3, n=7; Gr 5, n=3. Conclusions: Glofit + R-CHOP had a manageable safety profile with a low incidence of CRS, and continued to demonstrate durable responses with an improved CMR rate since the last data cut-off. These findings support the potential for favorable long-term outcomes with Glofit + R-CHOP as 1L treatment of DLBCL. Further analyses, including circulating tumor DNA data, will be presented.

Golcadomide (GOLCA; CC-99282), a Novel CELMoD Agent, Plus R-CHOP in Patients (pts) with Previously Untreated Aggressive B-Cell Lymphoma (a-BCL): Safety and Efficacy Results from Phase 1b Dose Expansion

Introduction Up to 40% of pts with diffuse large B-cell lymphoma (DLBCL) relapse after first-line chemo-immunotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). CELMoD agents such as GOLCA potently degrade target proteins Ikaros/Aiolos, resulting in antiproliferative, apoptotic, and immunomodulatory activity. GOLCA preferentially distributes to tissues and lymphoid organs. In a phase 1 study, GOLCA demonstrated a manageable safety profile with promising clinical activity as monotherapy in relapsed/refractory non-Hodgkin lymphoma (Michot et al. Blood 2021). CC-220-DLBCL-001 (NCT04884035) is an ongoing open-label, multicenter, dose escalation and expansion trial to assess safety and preliminary efficacy of CELMoD agents + R-CHOP for untreated a-BCL. GOLCA demonstrated a manageable safety profile in the dose escalation phase (Munoz et al. ICML 2023 abstract 438); we report combined results from the GOLCA dose escalation and expansion phases. Methods Eligible pts were ≥ 18 years, had untreated a-BCL with measurable disease (Lugano 2014), ECOG performance status ≤ 2 and International Prognostic Index (IPI) score 0-5 (2-5 in dose expansion). Pts were treated with R-CHOP plus GOLCA in 21-day (D) cycles (C) for up to 6C, or until disease progression/unacceptable toxicity/study withdrawal/physician decision. During dose escalation, pts received GOLCA at dose levels (DL): 0.2 mg D1-7 (DL-1), 0.4 mg D1-7 (DL1), and 0.4 mg D1-10 (DL2). DL2 met the dose-limiting toxicity threshold and was not continued in the expansion phase. During dose expansion, pts were randomized 1:1 to R-CHOP plus GOLCA at DL-1 or DL1. The primary endpoint for the expansion phase was safety of GOLCA at the recommended phase 2 dose (DL1) (based on adverse events [AEs]); secondary endpoints included overall response rate (ORR) and complete metabolic response (CMR) rate (assessed at end of treatment [EoT] by PET-CT [Lugano 2014]). Circulating tumor DNA (ctDNA) was measured at C1D1, C2D1, C3D1, and EoT using the PhasED-Seq assay. Results Across escalation and expansion, 78 pts were treated (DL-1, n = 35; DL1, n = 37; DL2, n = 6). Median age was 63.0 years, 56.4% were male, most had high-intermediate/high IPI (3-5) score at diagnosis (64.1%), Ann Arbor stage III-IV disease (83.3%), and germinal center B cell as cell of origin (51.3%); 83.3% pts had DLBCL histology. At data extraction (May 25, 2023), across escalation and expansion, 38 pts had treatment ongoing, 31 completed treatment, and 35 continued to follow-up. A total of 3 pts discontinued due to AEs, 1 each at DL-1, DL1, and DL2. In the safety population (n = 78), median GOLCA relative dose intensity (RDI) was 99.4%; 82.1% of pts received RDI ≥ 85%. RDI for CHOP components was > 90%. A total of 73 (93.6%) pts had ≥ 1 treatment-emergent AE (TEAE); 70 (89.7%) pts had ≥ 1 TEAE considered related to GOLCA; 65 (83.3%) pts had ≥ 1 grade 3/4 TEAE, 62 (79.5%) pts had ≥ 1 grade 3/4 TEAE considered related to GOLCA. The most frequently occurring grade 3/4 TEAEs were neutropenia (76.9%) and thrombocytopenia (32.1%) ( Table). A total of 30 (38.5%) pts had serious TEAEs, most frequently febrile neutropenia (preferred term: 11 pts, 14.1%); 12 (15.4%) pts had serious TEAEs of infection or infestation (system organ class); 6 pts (7.7%) had venous thromboembolisms considered related to GOLCA (4 deep vein thrombosis, 1 superficial thrombosis, 1 pulmonary embolism). Treatment-related AEs leading to GOLCA dose reduction or discontinuation occurred in 11 (14.1%) pts and 6 (7.7%) pts, respectively. After a median follow-up time of 4.1 months (range 0.3-12.3) and among all treated pts with EoT response available, 21/25 had CMR; together, 14/14 pts who received GOLCA 0.4 mg (DL1 and DL2) achieved CMR at EoT ( Figure). Among efficacy-evaluable pts (n = 56), ORR was 91.1% (95% CI 80.4-97.0). Pts treated with GOLCA at DL-1 and DL1 who were ctDNA high-risk (≥ 2.5 log hGE/mL) responded to study treatment (CMR-PMR) and had early decreases in ctDNA (Kaplan et al. ASH 2023). Conclusions GOLCA demonstrated a manageable safety profile, showed good combinability with R-CHOP, and did not compromise delivery of curative treatment. Efficacy results and substantial ctDNA decrease indicate robust clinical activity in frontline DLBCL, with a high CMR rate at EoT, particularly among patients treated at DL1. Study support Bristol Myers Squibb.

Tazemetostat in Combination with R-CHOP in Patients with High-Risk, Frontline Follicular Lymphoma (Epi-RCHOP): A Phase II Study from the Lysa

Background: Tazemetostat (TAZ), an enhancer of zeste homolog 2 (EZH2) inhibitor, is approved by the US Food and Drug Administration for the treatment of patients with relapsed/refractory (R/R) follicular lymphoma (FL) whose disease has mutant (MT) EZH2 and who have received ≥2 prior therapies or with R/R FL who have no satisfactory alternative treatment options. We previously reported that the RP2D of TAZ in combination with R-CHOP was 800mg BID in the phase 1 part of Epi-RCHOP study (NCT02889523). Here, we report results of the phase 2 part evaluating TAZ with R-CHOP + rituximab maintenance in a cohort of previously untreated high-risk FL patients. Methods: patients were eligible if aged 18-80 years, had histologically confirmed FL grade 1-3A, high-risk FLIPI (score of 3-5) and were in need of treatment according to GELF criteria. Induction treatment consisted in 6 cycles of RCHOP every 21 days and TAZ 800mg BID every day, starting on day 2 of cycle 1, plus 2 additional 21 days cycles of rituximab+TAZ (cycle 7 and 8). Responses were assessed at end of induction (EOI), and responders then received maintenance 1 (TAZ 6 mo + rituximab 12 mo) and maintenance 2 (12 mo of rituximab alone).The primary efficacy endpoint was PET-based complete response rate based on local assessment at the end of induction or at permanent treatment discontinuation, as determined by Cheson IWG 2014 Lugano Classification (Deauville scale 1-3); in addition bone marrow biopsy (BMB) was mandatory at EOI if involved at baseline and complete metabolic response (CMR) patients with missing assessment at EOI classified as partial responders. Sample size calculation was made with the expectation of an increase of 13% in CR, with an H0 hypothesis of 67% and an H1 assumption of 80%, leading to a theorical sample size of 62 pts, assuming a drop out of 10%. Initial assumption was that CR rate should be >76.4% to consider the combination eligible for further clinical evaluation in high risk FL patients. Results: As of June 14, 2022, 62 patients were enrolled between Aug2020 and Apr2022 across 20 centers (including a drop-out of 12 patients, 70 were enrolled in France, 4 in Belgium). Disease characteristics included: males 61.3%, median age 64.5 years, FLIPI 3/4/5 in 61.3%/32.3%/6.5%, EZH2 mutated 17.3% (n=9/46 assessed had EZH2 mutation; 16 undertermined), BM involvement 68.3%, circulating FL cells in 21%, and increased LDH in 50%. Fifty eight (93%) patients completed induction and initiated maintenance 1, 44 (71%) initiated maintenance 2. Fourteen patients permanently discontinued treatment: 4 before EOI not related to PD (2 COVID19 disease, 1 late onset neutropenia and 1 stopped therapy but accepted FU), and 9 after EOI (5 PD, 2 COVID19 disease, 1 neutropenia, 1 paralytic ileus and 1 patient's refusal). At EOI, 79% (95%CI 66.8; 88.3%) achieved complete metabolic response (CMR) and 16.2% PMR for an overall metabolic response rate of 95.2%, however, according to the stringent protocol definition, 16 patients who achieved CMR had no BMB assessment at EOI and were downgraded to PR leading to 53.2% CR and 41.9% PR rate at EOI. Complete response rates were significantly higher in EZH2 mutants (8/9 CMR 88.9%) versus 17/37 (45.9%) in EZH2 wild-type (WT) patients (Fisher exact test p=0.027). Figure 1 shows the AEs reported by more than 10% of patients. The most common grade 3-4 TEAEs were neutropenia (53.2%, only 3.2% febrile), thrombocytopenia (17.7%), anemia (16.1%). Serious AEs occurred in 14 patients, the two most frequent being Covid19 disease (6.5%) and gastrointestinal hypomotility (6.5%). This latter AE was the most frequent non-hematologic event (40.3%), followed by peripheral neuropathy (35.5%). After amending vincristine dose (Oct2020), 30 digestive AEs were reported (16 related to TAZ, mostly grade 1-2, only 1 grade 3, no sequelae). No SPM was observed. With a median follow-up of 19 months, 7 relapses (5 EZH2 WT and 2 undetermined) including 5 needing subsequent treatment and 2 deaths occurred (1 Covid19 disease, 1 after PD). Median PFS and median DOR were not reached and appeared to be similar irrespective of EZH2 status, 18-months PFS and OS rates were 89.3% and 98.3% respectively. Conclusions: Although the primary endpoint was not met due to missing BM assessments, TAZ + RCHOP combination demonstrated a promising complete metabolic response rate of 79% in this high-risk frontline FL population, with a manageable safety profile, after vincristine dose was reduced.

Chemotherapy-Free Combination of Blinatumomab and Ponatinib in Adults with Newly Diagnosed Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: Updates from a Phase II Trial

Background Blinatumomab and ponatinib demonstrated efficacy in patients with Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL). A chemotherapy-free regimen combining both drugs in the frontline setting may mitigate the risk of toxicities and the need for hematopoietic stem cell transplantation (HSCT). Methods In this phase II trial, patients ≥18 years of age with newly diagnosed Ph-positive ALL were eligible. They were required to have a performance status of ≤2, total bilirubin ≤2x the upper limit of normal (ULN), and ALT/AST ≤3x the ULN. Patients with uncontrolled cardiovascular disease or clinically significant central nervous system (CNS) comorbidities (except for CNS leukemia) were excluded. Patients received up to 5 cycles of blinatumomab in combination with ponatinib, followed by ponatinib maintenance for ≥5 years. Ponatinib 30mg daily was given during Cycle 1 and decreased to 15mg daily once a complete molecular response (CMR) was achieved. Patients also received 12 doses of prophylactic intrathecal (IT) chemotherapy with alternating cytarabine and methotrexate. The primary endpoint was the CMR rate. Secondary endpoints included response rates, safety measures, event-free survival (EFS), and overall survival (OS). Results Between June 2018 and May 2023, 62 pts with newly diagnosed Ph-positive ALL were treated. Baseline characteristics are shown in Table 1. Twenty-two patients were in complete remission (CR) at the start of therapy. Among 40 patients evaluable for hematologic response, 39 (98%) achieved CR/CRi; 1 patient had early death. Among 55 patients evaluable for molecular response, 37 (67%) achieved CMR after 1 cycle, and 46 (84%) achieved CMR at any time. Forty-seven patients were evaluated for measurable residual disease (MRD) by next-generation sequencing at a sensitivity level of 10 -6, of whom 43 (91%) were found to have negative MRD. Five of these patients with undetectable MRD by NGS had low-level BCR:ABL1 transcripts detected by PCR at the same time (ranging from 0.01% to 1.23% IS). Four of them had p190 transcript and one had p210. The median follow-up was 17 months (range, 2-61 months). Six patients (10%) relapsed after a median of 21 months of remission (range, 8-24 months): two relapsed in the bone marrow (one with acquired E225V mutation), one had an extramedullary-only relapse (Ph-negative and MYC-rearranged relapse), and three had a CNS-only relapse (after 20, 22, and 23 months). Four patients died (one from intracranial hemorrhage, one from post-procedural hemorrhage, one from brain aneurysm, and one following CNS relapse with intracranial edema and septic shock). One leukemia-related death occurred on study; the estimated 2-year EFS and OS rates were 77% and 89%, respectively (Figure 1). Only one patient underwent HSCT in first CR due to persistently low-level BCR:ABL1 positivity. Among the 52 patients in ongoing remission without HSCT, the median duration of response was 16 months (range, 2-61). Most adverse events were grade 1-2 and were consistent with the known toxicity profile of the two agents. Ponatinib was discontinued in two patients due to possibly related adverse events (cerebrovascular accident and coronary artery stenosis in one patient each). Conclusions The chemotherapy-free combination of blinatumomab and ponatinib is safe and effective in newly diagnosed Ph-positive ALL, with high rates of MRD negativity. Encouraging duration of remission and OS has been observed without the need for HSCT.

Epcoritamab SC + GemOx Leads to High Complete Metabolic Response Rates in Patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma Ineligible for Autologous Stem Cell Transplant: Updated Results from Epcore NHL-2

Background: Patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) who fail or are ineligible for autologous stem cell transplant (ASCT) have poor outcomes with standard chemotherapy, and novel, effective therapeutic options are needed. A retrospective analysis showed that treatment with rituximab and gemcitabine + oxaliplatin (GemOx) in a transplant-ineligible population resulted in a complete response rate of 33% in the overall population; among patients refractory to previous therapy, 10% achieved complete response (Cazelles et al, Leuk Lymphoma 2021). Epcoritamab, a subcutaneously administered (SC) CD3xCD20 bispecific antibody, has demonstrated deep, durable responses with a manageable safety profile as a single agent in patients with R/R DLBCL. Based on these data, epcoritamab SC was approved by the US FDA for the treatment of adults with R/R DLBCL, not otherwise specified, including DLBCL arising from indolent lymphoma, and high-grade B-cell lymphoma, after ≥2 lines of systemic therapy. In the EPCORE ™ NHL-2 phase 1/2 trial (NCT04663347), epcoritamab + GemOx treatment showed encouraging preliminary efficacy with overall expected and manageable safety in patients with R/R DLBCL who failed or were ineligible for ASCT. Here, we present updated results with longer follow-up. Methods: Adults with R/R CD20 + DLBCL who had failed or were ineligible for ASCT were enrolled. Patients received epcoritamab SC in 28-d cycles (Cs) as follows: weekly, C1-3; every 2 weeks, C4-9; every 4 weeks, C≥10 until progressive disease or unacceptable toxicity. Patients received GemOx every 2 weeks in C1-4. Step-up epcoritamab dosing (step-up doses 1 and 2 followed by 48-mg full doses) and corticosteroid prophylaxis were required in C1 to mitigate CRS. The primary endpoint was overall response rate (ORR) as assessed by PET-CT per Lugano criteria. Results: A total of 34 patients (median age, 71 y; range, 47-87) with a median follow-up of 20.3 mo (range, 1.0+ to 26.8) received epcoritamab SC 48 mg + GemOx on or prior to August 24, 2022. At the data cutoff date (April 24, 2023), treatment was ongoing in 35% of patients. A majority of patients (68%) had stage III or IV disease, 53% had primary refractory disease, 38% were refractory to ≥2 consecutive lines of prior therapy, and 79% were refractory to the last line of therapy. The median number of prior lines of treatment was 2 (range, 1-6); 11 patients (32%) had 3 or more prior lines of treatment. A total of 7 patients (21%) had prior CAR T, and 5 patients (15%) had previously received ASCT. The most common treatment-emergent AEs (TEAEs) of any grade (G) were thrombocytopenia/decreased platelet count (68%), diarrhea (59%), anemia (56%), CRS (56%), and neutropenia/decreased neutrophil count (56%). This trial was conducted amid the COVID-19 pandemic and 32% of patients experienced COVID-19. Most CRS events were low grade (53% G1-2; 3% G3) and primarily occurred following the first full dose (C1D15); no incidence of CRS resulted in epcoritamab discontinuation, and all events resolved. ICANS (G1) was reported in 1 patient; this event resolved in 2 d. No clinical tumor lysis syndrome was reported. There were 10 G5 TEAEs; in 2 cases, the contribution of epcoritamab could not be ruled out by the investigator (small intestinal perforation and multiple organ dysfunction syndrome; both patients had multiple confounding factors). The ORR was 91% (31/34), with 59% (20/34) of patients achieving complete metabolic response (CMR). Median times to response and CMR were 1.5 mo and 2.6 mo, respectively. The ORR and CMR rates were 94% and 39% among patients with primary refractory disease, 89% and 78% among patients ≥75 y of age, and 90% and 50% among patients with IPI ≥3 ( Table). Response rates were comparable for patients with and without prior CAR T treatment: ORR of 86% and CMR rate of 57% among patients with prior CAR T; ORR of 93% and CMR rate of 59% among CAR T-naive patients. Conclusions: Epcoritamab SC + GemOx led to high CMR rates in this difficult-to-treat R/R DLBCL population ineligible for transplant with high unmet medical need. No new safety signals were identified, and the safety profile was consistent with those of the individual drugs. These data are encouraging and underline the versatility of epcoritamab SC for the treatment of R/R DLBCL. Additional data and subgroup analyses will be presented.

PD-1 Blockade before Autologous Stem Cell Transplantation Improves Outcomes in Relapsed/Refractory Classic Hodgkin Lymphoma: Results from a Multicenter Cohort

Introduction: Single arm studies incorporating PD-1 blockade and/or brentuximab vedotin (BV) to salvage regimen have produced encouraging results in transplant-eligible relapsed/refractory classic Hodgkin lymphoma (R/R cHL) and are increasingly used in practice. As prospective randomized studies comparing PD1 based salvage to other salvage regimens are lacking, we conducted a retrospective study comparing post-transplant outcomes of R/R cHL patients who received PD1-based regimen and other novel and conventional regimen. Methods: Consecutive adult patients with R/R cHL who received salvage therapy and underwent autologous stem cell transplant (ASCT) between 2010 and 2021 at 5 United States academic institutions were included. Demographics and clinical variables were recorded at relapse by electronic health records review. Study Objectives were post-ASCT progression free survival (PFS) and overall survival (OS). Results: 981 pts of R/R cHL were identified. At relapse, median age was 31 (IQR: 21-43) years, 504 (52%) were male, 323 (49%) had advanced stage, 353 (41%) had extranodal disease (END), 185 (22%) had B symptoms, 345 (45%) were refractory to frontline therapy and 317 (32%) relapsed within a year of frontline therapy.308 (31%) received >1 line of salvage before ASCT. Patients were divided into 3 groups based on salvage therapy received: 1) 195 (20%) patients received a PD-1 agent with or without BV at any point before ASCT (PD-1 group), 2) 312 (32%) patients received BV at any point before ASCT without PD-1 (BV group), and 3) 474 (48%) patients received no novel agent before ASCT (chemo group). PFS was significantly higher in PD1 group (2-yr PFS 93.1 (CI 95: 89.4-96.9)%); compared to BV (2 yr PFS 73.9 (CI 95: 69.1-79.1)% , p <0.0001) or chemo groups (2 yr PFS 71.6 (CI 95: 67.6-75.9)% , p<0.0001). PFS was not different between the BV and chemo groups (p=0.88) (Figure 1). OS was not significantly different between PD-1 group (2 yr OS 96.2 % (CI 95: 93.2-99.2), p=0.06), BV group (2 yr OS 94.3% (CI 95: 91.7-97.0), p=0.2) and chemo group (2 yr OS 91.8% (CI 95: 89.3-94.4)). Amongst pts who were transplanted in complete metabolic response (CMR), we assessed post-ASCT PFS and OS based on salvage therapy received immediately before ASCT. Pts who received PD-1 as last salvage therapy had improved PFS compared to chemo (HR: 0.15 (CI 95: 0.07-0.3), p= <0.0001) and BV (HR: 0.2 (CI 95: 0.08-0.5), p= <0.001). Pts receiving PD-1 immediately before ASCT also had higher OS compared to those receiving chemo (HR: 0.2 (CI 95: 0.05-0.8), p= 0.02) but not BV (HR: 0.8 (CI 95: 0.4-1.3), p=0.1). There was no difference between BV and chemo group in regards to PFS and OS. In multivariable analysis that included time to relapse, B symptoms, END, pre-ASCT response, number of salvage therapy lines before ASCT, year of transplant and BV consolidation, PD-1 salvage therapy had significantly higher PFS compared to chemotherapy (HR: 0.3 (CI 95: 0.2-0.5), p= <0.001). BV group had significantly lower PFS (HR: 3.34 (CI 95: 1.8-6.0), group=0.002) compared to PD1 group. PFS was not different between BV and chemo group (p= 0.7). OS was similar between all 3 groups. Similar PFS and OS were seen among patients receiving PD-1 + BV (n=83) and PD-1 with or without chemo (n =112) (p=0.96 for PFS; p= 0.72 for OS); as well as for patients receiving PD-1 as part of their first salvage therapy (n=151) or later salvage treatments (n=44) (p=0.45 for PFS, p= 0.3 for OS). Patients who received PD1 based regimen as last salvage therapy pre-ASCT had significantly better PFS (HR: 6.8 (CI 95: 2.4-19.2), p= <0.0001) and OS (HR: 10.6 (CI 95: 2.5-44.8), p= 0.0001) compared to patients who received PD1 prior to their last line of salvage therapy per-ASCT. Conclusion: Receipt of PD-1 based salvage therapy at any point before ASCT is associated with significantly improved PFS compared to either BV or chemotherapy-based salvage treatments. In the subgroup of patients transplanted in CMR, PD1 based last salvage regimen were associated with higher PFS compared to chemotherapy and BV and higher OS compared to chemotherapy. PD1 based last salvage therapy pre-ASCT was associated with better survival compared to PD1 prior to last salvage therapy. Results of this study strongly support the use of PD-1 based salvage therapy for patients with R/R cHL. S.D., R.M., H.S contributed equally. R.S., M.M. contributed equally.

Glofitamab Plus Polatuzumab Vedotin Continues to Demonstrate Frequent and Durable Responses and Has a Manageable Safety Profile in Patients with ≥2L Relapsed/Refractory DLBCL, Including HGBCL, and in Patients with Prior CAR T-Cell Therapy: Updated Results from a Phase Ib/II Study

Background: Glofitamab (Glofit) is a CD20xCD3 bispecific antibody which engages and redirects T cells to eliminate B cells. Glofit monotherapy recently received FDA and EMA approval for treatment of relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) after ≥2 prior lines of therapy. Polatuzumab vedotin (Pola) is a CD79b-targeted antibody-drug conjugate that has a complementary mode of action to Glofit, with little toxicity overlap. In this open-label, multicenter Phase Ib/II study (NCT03533283), Glofit+Pola demonstrated durable responses and a manageable safety profile in patients with R/R DLBCL (Hutchings et al. ICML 2023). We present updated results with longer follow-up in patients with R/R DLBCL, including high-grade B-cell lymphoma (HGBCL), and in patients with prior chimeric antigen receptor (CAR) T-cell therapy. Methods: Patients receivedobinutuzumab 1000mg on Cycle (C) 1 Day (D) 1 to mitigate the risk of severe cytokine release syndrome (CRS). Pola 1.8mg/kg was given on C1D2 and D1 of C2-6 (21-day cycles). Glofit was given with step-up dosing in C1 (C1D8 2.5mg; C1D15 10mg; D1 of C2-12 10/30mg) for up to 12 cycles. The primary objective was to establish the recommended Phase II dose of Glofit when combined with Pola; this was previously identified as 30mg based on the dose-escalation phase and the NCT03075696 study (Hutchings et al. ASH 2021; Hutchings et al. J Clin Oncol 2021). Results: At the data cut-off (Jan 25, 2023), 111 patients had received ≥1 dose of study drug (safety population). The median age was 68 (range 23-82) years; 61.3% of patients were male; 50.5% had DLBCL not otherwise specified (NOS), 24.3% had HGBCL, 23.4% had transformed follicular lymphoma (trFL), and 1.8% had primary mediastinal large B-cell lymphoma (PMBCL). Most patients were refractory to their last prior therapy (71.2%). Median number of prior lines of therapy was 2 (range 1-7; 61.3% of patients had received ≥2), 24.3% had received prior CAR T-cell therapy. The overall response rate (ORR) in 109 efficacy-evaluable patients was 78.0%, with a complete metabolic response (CMR) rate of 56.0%. In patients with DLBCL NOS (n=56), ORR and CMR rate were 85.7% and 60.7%, respectively. In patients with trFL (n=26), ORR and CMR rate were 76.9% and 53.8%, respectively. In patients with HGBCL (n=25), ORR and CMR rate were 60.0% and 44.0%, respectively. The two patients with PMBCL achieved a CMR. In patients who had prior CAR T-cell therapy (n=27), ORR was 77.8% and CMR rate was 44.4%. In 61 patients who had a complete response, estimated 6- and 12-month duration of complete response (DOCR) rates were 89.2% and 73.1%, respectively ( Figure). Estimated 6-month and 12-month DOCR rates in patients with DLBCL NOS (n=34) were 84.2% and 59.2%, respectively; with trFL (n=14), were 92.9% and 85.7%; with HGBCL (n=11), both were 100%. In patients with PMBCL (n=2), the estimated 6-month DOCR was 100%. With a median follow-up of 13.0 months, median progression-free survival was 10.4 (95% confidence interval [CI]: 5.8-19.0) months ( Figure). Median overall survival was not reached after a median survival follow-up of 15.2 months. In 108/111 patients who had received ≥1 dose of Glofit, the most common adverse event (AE) was CRS (45.4% [Grade 1, 30.5%; Grade 2, 13.9%]). One patient had Grade 5 CRS in the context of an unresolved infection; the patient declined further CRS management when the event was Grade 3. Of 111 safety-evaluable patients, 27 (24.3%) had peripheral neuropathy (all Grade 1/2, 8 events were resolved). Glofit-related AEs potentially consistent with immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 3 patients and were all Grade 1/2. Grade 3/4 AEs were reported in 61.3% of patients, with neutropenia the most common event (29.7%). Serious AEs occurred in 58.6% of patients, and Grade 5 AEs occurred in 6.3% of patients (5/7 events due to COVID-19); 9.9% of patients discontinued any treatment due to an AE (6.3% discontinued Pola; 9.0% discontinued Glofit). Conclusions: Glofit+Pola demonstrated high response rates and durable responses in heavily pre-treated patients, the majority of whom were refractory to their last prior therapy, across all histologies, including in patients with HGBCL and those with prior CAR T-cell therapy. The safety profile was manageable and consistent with the individual drugs. The rates of CRS events and AEs potentially consistent with ICANS were low. Updated data will be presented.

Epcoritamab SC + R-Mini-CHOP Leads to High Complete Metabolic Response Rates in Patients with Previously Untreated Diffuse Large B-Cell Lymphoma Ineligible for Full-Dose R-CHOP: First Disclosure from Arm 8 of the Epcore NHL-2 Trial

Background: Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is a standard of care for previously untreated (1L) diffuse large B-cell lymphoma (DLBCL); however, some patients are not candidates for full-dose R-CHOP due to advanced age, frailty, or underlying comorbidities. For these patients, various attenuated treatment regimens have been evaluated, with low-dose R-CHOP (R-mini-CHOP) being widely adopted as a standard 1L regimen. However, outcomes are suboptimal, with overall response rates (ORRs) and complete metabolic response (CMR) rates around 70% and 40-60%, respectively, and a 2-y progression-free survival rate of only 47%, leaving substantial room for improvement. Epcoritamab, a subcutaneous (SC) CD3xCD20 bispecific antibody, was approved by the US FDA for the treatment of adults with relapsed or refractory DLBCL, not otherwise specified, including DLBCL arising from indolent lymphoma, and high-grade B-cell lymphoma after ≥2 lines of systemic therapy. In the 1L setting in patients with high-risk DLBCL, epcoritamab SC with full-dose R-CHOP had a favorable safety profile and showed promising efficacy, including an ORR of 100% (Falchi et al, ASCO 2023). Here we report initial data from arm 8 of the EPCORE™ NHL-2 study (NCT04663347; phase 1/2) evaluating epcoritamab SC + R-mini-CHOP in 1L DLBCL. Methods: Adults with 1L CD20 + DLBCL who were not considered candidates for full-dose R-CHOP due to age ≥75 y or age ≥65 y with comorbidities (reduced left ventricular ejection fraction, history of myocardial infarction [>6 mo prior to enrollment], exertional chest pain, arrhythmia [grade ≤2], hypertension requiring treatment, or diabetes) were enrolled. Patients received epcoritamab SC (QW, cycles 1-2 [21 d each]; Q3W, cycles 3-6 [21 d each]; Q4W, cycles 7-8 [28 d each]) with R-mini-CHOP in cycles 1-6 (Q3W). A safety run-in was conducted to confirm acceptability of the safety profile. The primary endpoint of arm 8 was ORR as assessed by PET-CT per Lugano criteria. Results: As of April 24, 2023, 28 patients had received epcoritamab SC 48 mg + R-mini-CHOP. The median age was 81 y, 14 patients (50%) had IPI 3-5, 10 patients (36%) had bulky disease (>6 cm), and 15 patients (54%) had stage IV disease. At the data cutoff, median follow-up was 6.2 mo (range, 2.5+ to 11.7), with 9 patients (32%) having completed treatment and 15 patients (54%) still on treatment. R-mini-CHOP median relative dose intensity was ≥94%. There were no dose-limiting toxicities. The most common treatment-emergent AEs (TEAEs) of any grade were cytokine release syndrome (CRS; 43%), neutropenia (32%), fatigue (25%), anemia (21%), constipation (21%), and hypokalemia (21%). TEAEs decreased over time; 3 patients (11%) discontinued epcoritamab SC due to TEAEs. One grade 5 TEAE (cytomegalovirus infection reactivation) was recorded. CRS events were primarily low grade (grade 1-2: 39%, grade 3: 4%, grade ≥4: 0%), timing was predictable, and a majority of events were observed after the first full dose (cycle 1, day 15); all events resolved, with a median time to resolution of 3 d (range, 1-7). No ICANS events were reported. All 20 efficacy-evaluable patients had a response (ORR, 100%), with 17 patients (85%) achieving CMR. Median time to response was 1.4 mo ( Figure). At both month 6 and month 9, most patients who achieved CMR remained in CMR, suggesting durability of response. The study is ongoing and updated results will be presented. Conclusions: Epcoritamab SC + R-mini-CHOP showed encouraging efficacy with high response rates in patients with 1L DLBCL who cannot tolerate full-dose R-CHOP, including elderly, frail, and high-risk patients. There were no new safety signals, and findings were consistent with previously reported data, supporting the feasibility of the combination. These results warrant further investigation of epcoritamab-based therapies in 1L DLBCL.

Real World Data on Safety and Efficacy of Pegylated Interferon (PEG-IFN) in Patients with Myeloproliferative Neoplasms (MPN)

Introduction: Patients with Myeloproliferative neoplasms (MPN) require cytoreduction to normalise the elevated counts to reduce risk of thrombosis. We present real world data from a single centre in the UK on PEG-IFN in patients with MPN. Methods: Real World prospective data collection of patients who were commenced on PEGIFN between Jan 2014 to July 2022. Patient demographics, indications to treat, dose and response rates at quarterly follow up in year 1 and biannually from year 2 onwards, thrombotic events, transformation, discontinuation rate and adverse events were collected and presented here. Starting dose of PEG IFN was 45 mg/2 weeks; it was increased gradually to a maximum of 180 mg/week. Once complete response (CR) according to ELN criteria was achieved dose was reduced to minimum effective dose. Results: This study accrued 212 patients with MPN who commenced PEGIFN from Jan 2014 to July 2022. Median duration of follow up was 60 m (range 12 - 114 m); 92 males, 120 Females; 93 patients were diagnosed to have Polycythaemia Vera PV), 98 Essential Thrombocythemia (ET) and 21 had Myelofibrosis (MF). 154 patients had mutated JAK2, 41 CAL-R (type 1 in 25 and type 2 in 16), 3 MPL and 13 were negative for any mutations. PEG IFN was chosen as first line treatment in 89 patients and at subsequent line after Hydroxycarbamide (intolerant n=, ineffective n= or contraindicated n= due to ulcers) or phlebotomy in 123 patients. Complete Haematological response according to ELN criteria were achieved and sustained in 141 (66%) at a median of 6 m (range: 3 to 60), Partial response in 52 (24%) and no response in 15 (7%) patients. Molecular response was assessed in JAK2 mutated patients (n=153) and shown in figures 1 and 2 with respect to diagnosis and response rate. Complete molecular response was seen in 4 patients at a median of 58 m. Deeper sustained responses were associated with earlier use of PEG-IFN in the course of disease, younger patients as first line as compared to it being used at second or subsequent line (74% Vs 63%) . PEG IFN was discontinued in 36 patients at 6 to 18 m due to being ineffective in 7, intolerant in 18, unrelated causes in 10 and disease progression/transformation in 3 patients (1 AML 2 MF). Thrombotic events whilst on PEG-IFN were seen in 14 patients (11 arterial and 3 venous) unrelated to control of blood counts, 12 were JAK2+ MPN and 10 patients had PV. Adverse events such as hypothyroidism in 8 (3.7%), grade 1-2 hepatitis in 46 (21.6%), grade 3 hepatitis in 4 (1.8%), alopecia in 2, skin rash in 3, worsening of psoriasis in 2 patients were managed with reduction or temporary suspension of PEG IFN and recommencing at a lower dose and frequency. 29 patients had underlying depression and 22 were stable on anti-depressants, 4 patients came off interferon due to panic attacks. 5 patients developed second primary malignancy on PEG IFN. Conclusion: PEG-IFN is a safe and effective cytoreductive agent in all myeloproliferative neoplasms and is an alternative to Hydroxycarbamide, as a second line option in older patients and a first line option in younger patients. It corrects the elevated counts but also modifies the disease course as evident in JAK2 VAF reduction and sustained haematological responses and reduced risk of thrombosis and transformation. In addition, it is least restrictive in terms of quality of life such as family and holiday planning. Figure 1: Waterfall plot: JAK2 allele burden percentage change on Peg-IFN, each bar represents the % change in allele burden for one patient, and ranked Figure 2: Fall in JAK2 VAF with respect to type of Haematological Response

Subcutaneous Mosunetuzumab Is Active and Has a Manageable Safety Profile in Patients with Previously Untreated, Low-Tumor Burden Follicular Lymphoma: Initial Results from the Phase II Morningsun Study

Background: Mosunetuzumab is a CD20xCD3 bispecific antibody that is approved for the intravenous (IV) treatment of patients with relapsed/refractory (R/R) follicular lymphoma (FL) who have received at least two prior lines of systemic therapy, and is suitable for administration in the outpatient setting. In an ongoing Phase I/II study (NCT02500407), IV mosunetuzumab induced durable responses and had a manageable safety profile in patients with heavily pre-treated R/R indolent and aggressive B-cell non-Hodgkin lymphomas (NHL) when administered as a fixed-duration treatment (Budde et al. J Clin Oncol 2022). Subcutaneous (SC) dosing was also evaluated and showed similar efficacy to IV dosing and a manageable safety profile (Budde et al. ASH 2022). MorningSun (NCT05207670) is an ongoing, open-label, multicenter, Phase II study evaluating the efficacy, safety and pharmacokinetics of SC mosunetuzumab in patients with selected B-cell NHLs, including those without prior treatment (Flinn et al. ASCO 2022). For the first time, we present initial efficacy and safety data for patients with previously untreated, low-tumor burden FL who were enrolled into MorningSun at community and academic centers in the United States. Methods: Inclusion criteria include previously untreated Grade (Gr) 1 or 2 FL, low tumor burden by GELF criteria, Ann Arbor stage III or IV disease, and ECOG performance status 0-2. Mosunetuzumab is administered without mandatory hospitalization by SC injection in 21-day cycles. In Cycle (C) 1, mosunetuzumab is given on Day (D) 1 (5mg), D8 (45mg) and D15 (45mg). In C2+, mosunetuzumab is given on D1 only (45mg). Treatment is continued for up to 17 cycles (~1 year). Patients who are in complete metabolic response (CMR) at C8 can discontinue active treatment and enter long-term follow-up. Premedication with dexamethasone (20mg) is mandatory in C1 and C2 and optional thereafter. Acetaminophen and diphenhydramine may also be given. The primary endpoint is the rate of progression-free survival at 24 months. Results: At data cut-off (March 6, 2023), 30 patients had been enrolled (19 at community centers and 11 at academic centers). Median age was 56 years. All patients had ECOG performance status 0-1, and a minority had B symptoms ( Table 1). The median duration of follow-up was 4.2 months (range: 0.2-11.1) and the median number of cycles received was 7 (range: 1-13). Among 24 patients who had at least one post-baseline tumor assessment, 23 achieved an objective response (95.8%; 95% CI: 78.9-99.9), including 20 who achieved a CMR (83.3%; 95% CI: 62.6-95.3). All responses were observed at the first post-baseline tumor assessment in C4 (median time to response: 2.6 months; 95% CI: 2.6-2.8). At cut-off, responses were ongoing in all patients who achieved CMR and 2 of 3 patients who achieved partial metabolic response. The most common adverse event (AE) was injection site reaction (53.3% of patients), all of which were Gr 1 (43.3%) or Gr 2 (10.0%). Cytokine release syndrome (CRS) occurred in 43.3%. Most patients had Gr 1 CRS ( Table 2). No Gr ≥3 CRS events or discontinuations due to CRS were reported. CRS occurred in C1 only. All CRS events resolved. Other common (>20%) AEs were headache (50.0%), nausea (30.0%), fatigue (26.7%), pyrexia (23.3%), chills (23.3%) and alanine aminotransferase increased (23.3%). Gr ≥3 AEs in ≥5% of patients were neutrophil count decreased (2 patients; 6.7%). Serious AEs (SAEs) in ≥5% were CRS (2 patients; 6.7%). No SAEs of infection were reported. AEs potentially consistent with immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 2 patients (Gr 1 confusional state and Gr 1 memory impairment in one patient each); both events resolved. No mosunetuzumab-related AEs leading to discontinuation occurred and no Gr 5 (fatal) AEs were reported. Conclusions: Initial MorningSun data support that SC mosunetuzumab is active in patients with previously untreated, low-tumor burden FL. Safety data demonstrate a manageable safety profile that is consistent with that seen in patients with R/R B-cell NHLs and is supportive of outpatient administration.

Phase 2 Trial of Single-Agent Cobimetinib for Adults with Histiocytic Neoplasms

Background: Histiocytic neoplasms (HN) are clonal hematopoietic disorders characterized by diverse mutations in the mitogen-activated protein kinase (MAPK) pathway. BRAF inhibition is highly effective for patients with HN harboring the BRAFV600E mutation, and implementation of BRAF inhibitors transformed management of BRAFV600E-mutated Erdheim-Chester disease (ECD) and Langerhans cell histiocytosis (LCH). No standard or approved therapies existed, however, for patients with HN lacking the BRAFV600E mutation. Efficacy of mitogen-activated protein kinase (MEK) inhibition for HN harboring various MAPK pathway mutations has been observed in case reports and series. We present here results from 26 patients treated in a phase 2 trial of single-agent cobimetinib for adults with HN (NCT02649972). The data were submitted to the Food and Drug Administration (FDA) in a supplemental new drug application for cobimetinib, and FDA approval was granted in October, 2022. Methods: This is an open-label phase 2 trial of cobimetinib 60mg daily for patients with (1) BRAFV600-wildtype (wt) histiocytosis or (2) BRAFV600-mutant histiocytosis intolerant or without access to BRAF inhibitor therapy. Eligible patients were age 16 or older, had histologic confirmation of HN diagnosis, ECOG 0 to 3, multi-system HN or HN refractory to conventional (i.e. chemotherapeutic or immunosuppressive) therapy or single-system HN deemed unlikely to benefit from conventional therapy, and with disease measurable by positron emission tomography (PET) Response Criteria (PRC). Patients were eligible with any tumor mutation or with no identified tumor mutation. The primary endpoint was overall response rate (complete metabolic response + partial metabolic response; ORR) by PRC. Secondary endpoints included safety (CTCAE 4.0), duration of response (DoR) and progression-free survival (PFS) as determined by modified PERCIST, overall survival (OS), and response rate by RECIST. Data cut-off was March 28, 2019 for efficacy evaluation, and safety follow-up cut-off was September 28, 2019. Results: Twenty-six patients (13 ECD, with Rosai-Dorfman disease [RDD], 4 with LCH, 2 with juvenile xanthogranuloma [JXG], 3 with mixed histiocytosis) with a median age of 50.5 were analyzed. Six patients had BRAFV600E-mutant disease, one of these with additional mutations in KRAS and NRAS. Of the remaining 20, 15 had non-BRAFV600 MAPK pathway mutations (4 KRAS [one of them with ARAF mutation as well], 6 MEK1, 1 MEK2, 1 RAF1, 1 ARAF, 2 non-V600 BRAF mutations, and 5 had no mutation identified). Twenty-six patients were evaluable for safety, 24 for PRC, 19 for RECIST. Response rates are listed in Table 1 and PRC responses are presented in Figure 1. The ORR by PRC was 83.3% (95% CI 62.62-95.26), in the PRC-evaluable population. Responses were observed across MAPK mutations, histiocytosis subtypes and tumor genotypes. By BRAFV600 status, in PRC-evaluable population, the ORR for BRAFV600E-mutant disease was 100% (95% CI 47.82-100), and for BRAFV600-wt disease was 78.9% (95% CI 54.43-93.95). Median DoR was 31.1 months (95% CI 16.8-NE) in the PRC-evaluable population. ORR by RECIST was 63.2% (95% CI 38.36-83.71), in the RECIST-evaluable population. Three patients died on study, none related to cobimetinib. Grade 3 or 4 toxicities in >10% of patients included decreased lymphocyte count (19%), increased blood creatine phosphokinase (12%), decreased ejection fraction (12%), hypokalemia (12%), hyponatremia (12%), acute kidney injury (12%) and dyspnea (12%). Conclusions: Cobimetinib demonstrates robust efficacy in HN irrespective of underlying MAPK pathway mutation, including BRAF-wt and BRAFV600-mutant HN. Safety of cobimetinib in this patient population was consistent with the known safety profile.

A Phase 1 Dose Escalation Trial of Third-Generation CD19-Directed CAR T-Cells Incorporating CD28 and Toll-like Receptor 2 (TLR2) Intracellular Domains for Relapsed or Refractory B-Cell Non-Hodgkin Lymphomas (ENABLE)

Introduction: Chimeric antigen receptor (CAR) T cell therapies directed against CD19 and incorporating either CD28 or 4-1BB intracellular co-stimulatory domains are a standard of care for relapsed or refractory (r/r) B-cell lymphomas. CD19-directed CAR T-cell products employing CD28 co-stimulation yield high response rates, but have been associated with higher rates of immune effector cell-associated neurotoxicity syndrome (ICANS) and severe cytokine release syndrome (CRS) than 4-1BB co-stimulated products. There is a need for CAR T-cell products that combine high efficacy with low toxicity. Toll-like receptor 2 (TLR2) is expressed by T-cells, and its engagement enhances T-cell expansion, modulates cytokine production, and promotes long-lived T-cell memory. In preclinical studies, interposition of an intracellular domain from TLR2 between CD28 and CD3ζ resulted in reduced CAR T-cell production of ICANS-associated cytokines GM-CSF and IFN-γ, while maintaining production of the homeostatic cytokine IL-7. We investigated the safety and efficacy of a novel third generation CD19-directed CAR T-cell product, which combines CD28 and TLR2 co-stimulatory domains ( Figure). Methods: We completed a first-in-human phase 1 dose escalation trial of WZTL-002, comprising autologous 1928T2z CAR T-cells (‘ENABLE’, NCT04049513) for patients with r/r B-cell non-Hodgkin lymphomas (B-NHL). A 3+3 dose escalation design was used, with doses from 5 × 10 4 to 1 × 10 6 viable CAR T-cells/kg body weight. Eligible participants had radiologically assessable disease, satisfactory organ function and no central nervous system (CNS) involvement by lymphoma. Bridging therapy was permitted after leukapheresis and pending CAR T-cell manufacture and release. WZTL-002 CAR T-cells were administered intravenously after 3 days of fludarabine (30mg/m 2/day) and cyclophosphamide (500mg/m 2/day) lymphodepletion. Adverse events (AEs) were graded by CTCAE 5.0 except CRS and ICANS (graded by American Society for Transplantation and Cellular Therapy criteria). Response assessment was by PET/CT at month 3, per Lugano 2014 criteria. Pharmacokinetic analyses were by droplet digital PCR for CAR transgenes in blood mononuclear cells. Results: Of 21 patients treated within the dose escalation trial, median age was 57 years (range 23 - 70); 10 (48%) were female; 4 (19%) Māori. Lymphomas were of large cell histology in 17 (81%, Table). Participants had received a median of 4 prior lines of therapy, including autograft in 11 (52%) and allograft in 1. Product phenotyping showed WZTL-002 CAR T-cells were median 49% CD4 +, 41% CD8 + and 34% CD62L +. As of June 14 2023, all patients had reached the primary follow-up timepoint (3 months after WZTL-002 administration). Grade ≥ 3 AEs occurring in ≥ 10% of recipients were: neutropenia (95%), lymphopenia (57%), hypogammaglobulinemia (57%), anaemia (43%), febrile neutropenia (43%), thrombocytopenia (24%) and tumor pain (19%). Grade 1 - 2 CRS occurred in 13 patients (62%); 6 received tocilizumab and 3 dexamethasone. No CRS of grade ≥ 3, and no ICANS of any grade, occurred. Two grade 4 cytopenia dose limiting toxicities occurred at day 21 (one each at 5 × 10 5 and 1 × 10 6 cells/kg), both resolved to grade 2 by day 90. Maximum tolerated dose was not reached. Responses were seen at all dose levels with complete metabolic response in 11 (52%) at month 3. WZTL-002 CAR T-cells expanded at all dose levels. Among recipients of 0.5 - 1.0 × 10 6 CAR T-cells/kg (n = 12), median peak CAR T-cell level (C max) was 93,950 transgene copies/μg genomic DNA (reached at median day 10) and CAR T-cells persisted in 9 of 11 assessed (82%) at day 90. A recommended phase 2 dose (RP2D) range of 0.5 - 1 × 10 6/kg was selected. Conclusions: In this dose escalation trial of a novel third-generation CD19-directed CAR T-cell product that combines CD28 and TLR2 co-stimulatory domains for r/r B-NHL, we observed no severe CRS, no ICANS of any grade and complete responses at all dose levels. At RP2D, in vivo CAR T-cell expansion was similar to or greater than other CD19-directed products. In conjunction with preclinical findings, this study suggests interposition of a TLR2 domain between CD28 and CD3ζ domains may reduce CAR T-cell-related ICANS risk while retaining efficacy. Enrolment to a dose expansion cohort has commenced and will assess outpatient management and the safety and efficacy of WZTL-002 CAR T-cells manufactured using a closed automated process.

Efficacy and Safety of Reduced-Dose Polatuzumab Vedotin, Rituximab, Cyclophosphamide, Doxorubicin, and Prednisone (Pola-R-CHP) in Patients over 80 with Newly Diagnosed Diffuse Large B-Cell Lymphoma (DLBCL)

Background: The standard treatment for newly diagnosed DLBCL has been R-CHOP for many years. Recently, Pola-R-CHP using polatuzumab vedotin has been reported to have superior efficacy to R-CHOP and is available as first-line treatment for DLBCL. However, the patients in the phase 3 POLARIX trial were under 80, and the efficacy and safety for patients over 80 are not established. To investigate the efficacy and safety of Pola-R-CHP in the elderly, we conducted this study. Patients and Methods: From September 2022 to March 2023, we retrospectively analyzed patients with newly diagnosed DLBCL treated with Pola-R-CHP at Anjo Kosei Hospital. Patients previously treated for hematologic malignancies were excluded. The dosages of polatuzumab vedotin and rituximab were not reduced, and the dosages of cyclophosphamide, doxorubicin, and prednisone or treatment schedules were determined by the treating physician. The primary endpoint was the rate of treatment continuation without early termination, and secondary endpoints were efficacy, progression free survival (PFS), and safety. Results: A total of 29 patients (younger group: under 80, n = 21; elderly group: over 80, n = 8) were consecutively enrolled. The median age in the younger group was 64 (range 42-78) and in the elderly group was 82.5 (range 80-94). Patient characteristics, including history of malignancy (24% vs 13%, p=0.50), lifestyle diseases (43% vs 50%, P = 0.73), and sanctuary lesions (10% vs 25%, P = 0.28), were comparable in both groups. However, advanced disease was significantly higher in the younger group (76% vs 38%, P = 0.05). The Revised IPI scores were similar in both groups (Very good: 5% vs 0 %, Good: 29% vs 50%, Poor: 67% vs 50%, P = 0.50). Cyclophosphamide, doxorubicin, and prednisone were administered at full dose in 71% of the younger group, but were reduced in all patients in the elderly group (P = 0.001). Peg-GCSF was administered during treatment in all cases in the elderly group. The median days to the 6th cycle were 111 (range 105-126) in the younger group and 114.5 (range 107-124) in the elderly group, with no significant difference (P = 0.37). The rate of treatment continuation until the 6th cycle was 86% in the younger group and 100% in the elderly group, with no significant difference (P = 0.27, Fig A). Three patients in the younger group discontinued treatment due to deterioration of comorbidities (n=1), early death due to infection (n=1), and insufficient treatment effect leading to regimen change (n = 1). In the positron emission tomography (PET) / computer tomography (CT)-based response evaluation after treatment, complete metabolic response was observed in 48% of the younger group and 50% of the elderly group, and partial metabolic response was observed in 19% and 13% respectively (P = 0.90, Fig B). The CT based response were evaluated during the treatment. After 2 cycles of treatment, partial response was achieved 86% of patients in younger group and 75% of those in elderly group (P = 0.50). In the elderly group, complete response was confirmed in 75% of the patients at the end of cycle 6. The 6-month PFS after treatment initiation was 95% in the younger group (95% confidence interval, 71-99%) and 100% in the elderly group (p = 0.54). The incidence of grade 3 or higher non-hematologic toxicity was 28% in the younger group and 48% in the elderly group (P = 0.27). The incidence of febrile neutropenia or grade 3 or higher infection was 76% in the younger group and 75% in the elderly group (P = 0.95), and one case of grade 5 sepsis was observed in the younger group. There were no cases of cytomegalovirus reactivation or infection. Peripheral neuropathy occurred in 3 cases (14%) in the younger group but not in the elderly group. Conclusion: Pola-R-CHP is a feasible and effective treatment in clinical practice for patients over 80 with newly diagnosed DLBCL, with efficacy equivalent to that in younger patients. Further confirmation of long-term treatment effects and safety is necessary, but reduced-dose Pola-R-CHP is a reasonable choice as a standard treatment for newly diagnosed DLBCL in the elderly.

Subcutaneous Epcoritamab Plus Lenalidomide in Patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma from EPCORE NHL-5

Background: The prognosis for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) is poor, even if treated with salvage chemotherapy and autologous stem cell transplantation. CAR T cell therapy provides long-term remission in only 40% of patients. Epcoritamab, a subcutaneous CD3xCD20 bispecific antibody developed using the DuoBody ® platform, received accelerated FDA approval for adults with R/R DLBCL not otherwise specified, including DLBCL arising from indolent lymphoma, and high-grade B-cell lymphoma after ≥2 lines of systemic therapy. Single-agent epcoritamab has demonstrated deep and durable responses (overall response rate, 63%; complete responses, 40%) and a manageable safety profile in patients with R/R large B-cell lymphoma in the EPCORE NHL-1 trial (Karimi et al, ASCO 2023, abstract 7525). Combining epcoritamab with antineoplastic agents that have different mechanisms of action may offer enhanced clinical benefit to patients. Therefore, EPCORE NHL-5 (NCT05283720) evaluated the safety, tolerability, and preliminary efficacy of epcoritamab, as well as defining its recommended dose when coadministered with other antineoplastic agents in patients with non-Hodgkin lymphoma. Here, we present results from arm 1 that evaluated epcoritamab combined with lenalidomide in patients with R/R DLBCL. Methods: EPCORE NHL-5 is a phase 1b/2, nonrandomized, open-label, multicenter study. In arm 1, adults with CD20 + R/R DLBCL (ECOG 0-2) received subcutaneous epcoritamab (weekly during cycle 1-3, every 4 weeks during cycle 4-12) and oral lenalidomide (once daily on days 1-21) for 12 cycles of 28 days. Patients had received at least 1 prior combined systemic therapy that contained an anti-CD20 monoclonal antibody. The primary endpoint was the identification of dose-limiting toxicities (DLTs). Key secondary endpoints included investigator-assessed best overall response by Lugano 2014 criteria and time to response. Safety endpoints included severity and incidence of adverse events (AEs) including AEs of special interest to epcoritamab (cytokine release syndrome [CRS], immune cell-associated neurotoxicity syndrome [ICANS], and clinical tumor lysis syndrome). Results: As of May 22, 2023, 26 patients (median age, 71 years; DLBCL, n=24 [92%]; follicular lymphoma grade [G] 3b, n=2 [8%]) had received epcoritamab plus lenalidomide. Median duration of epcoritamab exposure was 3.8 months (range, 0-7.5) and median duration of lenalidomide exposure was 4.0 months (range, 0.1-8.2); 15 patients (58%) remain on epcoritamab and lenalidomide. Median number of prior lines of therapy was 1 (range, 1-4), with 15 (58%) receiving 1 prior line of anticancer therapy. Six patients (23%) had received prior CAR T and 2 patients had undergone hematopoietic stem cell transplantation. One DLT (neutropenia) was observed. The most common G3-4 treatment-emergent AEs (TEAEs) were neutropenia (n=15; 58%), anemia (n=4; 15%), thrombocytopenia (n=4; 15%), and febrile neutropenia (n=3; 12%). Primary granulocyte colony-stimulating factor prophylaxis was not mandatory. TEAEs led to epcoritamab discontinuation in 1 patient (3.8%; thrombocytopenia). No patients experienced a TEAE leading to death that was considered related to epcoritamab. CRS was predominantly low grade (73% [19/26] any grade; 65% G1-2; 8% G3) and occurred mostly after the first full dose (C1D15). Preliminary biomarker analysis showed pharmacodynamic profiles consistent with the mechanism of action of epcoritamab. These include predictable cytokine peaks immediately after the first full dose (IFN-gamma, IL-2, and IL-6) with a rapid and sustained depletion of peripheral B cells. One patient experienced ICANS (G3), which resolved after 2 days. Among response-evaluable patients (n=24), the overall response rate was 75% (95% CI, 53.3, 90.2). Complete metabolic responses were seen in 14 patients (58%) and partial responses in 4 patients (17%), of which 3 were ongoing at time of data cutoff ( Table). Median time to first response was 1.8 months (range, 1.0-2.8). Follow-up is ongoing. Conclusions: Epcoritamab combined with lenalidomide showed promising antitumor activity with a tolerable safety profile in patients with R/R DLBCL.

Efficacy and Safety of Valemetostat Monotherapy in Patients with Relapsed or Refractory Peripheral T-Cell Lymphomas: Primary Results of the Phase 2 VALENTINE-PTCL01 Study

Introduction: Peripheral T-cell lymphoma (PTCL) is an aggressive non-Hodgkin lymphoma (NHL), with limited available treatment options for patients (pts) with relapsed or refractory (R/R) disease. Valemetostat tosylate (valemetostat) is a novel and potent dual inhibitor of enhancer of zeste homolog (EZH)2 and EZH1, which is approved in Japan for the treatment of R/R adult T-cell leukemia/lymphoma (ATLL). Here, we report primary results for pts with R/R PTCL treated with valemetostat in the open-label, single-arm, global, phase 2 VALENTINE-PTCL01 study (DS3201-A-U202; NCT04703192). Methods: Pts were ≥ 18 years of age, had a confirmed diagnosis of PTCL, had R/R disease after ≥ 1 prior line of systemic therapy, and pts with anaplastic large cell lymphoma (ALCL) had received prior brentuximab vedotin treatment. Pts received oral valemetostat 200 mg/day in continuous 28-day cycles until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR), assessed by blinded independent central review of PTCL following computed tomography (CT)-based response assessment according to Lugano 2014 criteria. Secondary efficacy endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Positron emission tomography (PET)-CT-based response assessment by Lugano 2014 criteria was an exploratory endpoint. Efficacy analyses included all pts who received ≥ 1 dose of valemetostat and had an eligible PTCL subtype confirmed by central hematopathology review; safety analyses included all pts who received ≥ 1 dose of valemetostat. Results: A total of 133 pts with R/R PTCL were enrolled and received ≥ 1 dose of valemetostat. Pts had a median age of 69 years (range 22-85) and 91 pts (68.4%) were male. Pts had received a median of 2 prior lines of therapy (range 1-12) and 35 pts (26.3%) received prior hematopoietic cell transplant (HCT; autologous, n = 32; allogeneic, n = 5). PTCL subtype eligibility was confirmed in 119 pts: 42 pts (31.6%) had angioimmunoblastic T-cell lymphoma (AITL), 41 (30.8%) had PTCL, not otherwise specified (PTCL, NOS), 9 (6.8%) had ALCL (7 [5.3%] ALK-negative and 2 [1.5%] ALK-positive), 8 (6.0%) had nodal PTCL with T follicular helper cell phenotype, and 19 (14.3%) had other PTCL subtypes. As of data cutoff (May 5, 2023), 32 pts (24.1%) were still receiving treatment; reasons for treatment discontinuation included progressive or relapsed disease in 46 pts (34.6%), clinical progression in 19 pts (14.3%), adverse event in 13 pts (9.8%), and 12 pts (9.0%) discontinued study drug to proceed with allogeneic HCT. Median treatment duration was 18 weeks (range 0.3-93.4) and median duration of follow-up was 10.5 months (range 0.2-21.5). Among 119 efficacy-evaluable pts, the CT-based ORR was 43.7% (n = 52) (95% confidence interval [CI], 34.6-53.1), including 17 pts (14.3%) achieving CR and 35 pts (29.4%) achieving PR as best overall response. Median DOR was 11.9 months (95% CI, 7.8-not evaluable [NE]) and median time to response was 8.1 weeks (range 5-37). ORR by PTCL subtype ranged from 31.7% for PTCL, NOS to 54.8% for AITL (Table 1). Using PET-CT-based response assessment, ORR was 52.1% (n = 62) (95% CI, 42.8-61.3), including 32 pts (26.9%) with a complete metabolic response. Median CT-based PFS was 5.5 months (95% CI, 3.5-8.3) and median OS was 17.0 months (95% CI, 13.5-NE). Of 133 pts in the safety analysis set, 128 pts (96.2%) experienced ≥ 1 treatment-emergent adverse event (TEAE) of any grade, 77 pts (57.9%) experienced grade ≥ 3 TEAEs, and 53 pts (39.8%) experienced serious adverse events. The most common all grade and grade ≥ 3 TEAE was thrombocytopenia (Table 2). Overall, 13 pts (9.8%) experienced a TEAE that led to treatment discontinuation, 21 pts (15.8%) had a TEAE that led to dose reduction, and 66 pts (49.6%) had a TEAE that led to dose interruption. Conclusions: Valemetostat demonstrated a high ORR of 43.7% with durable responses (median DOR of 11.9 months) in pts with R/R PTCL, and responses were observed across all PTCL subtypes. A valemetostat dose of 200 mg/day was tolerable; safety analysis showed that the most common TEAEs were cytopenias. These primary results from the VALENTINE-PTCL01 study suggest that valemetostat provides a clinically meaningful benefit for pts with R/R PTCL.

Comprehensive Analysis of Treatment Related Morbidity and Progression -Free Survival in the GHSG Phase III HD21 Trial

INTRODUCTION The GHSG-HD21 trial for newly diagnosed adult patients with advanced-stage classical Hodgkin lymphoma (AS-cHL) compares the BrECADD regimen (Brentuximab vedotin, etoposide, cyclophosphamide, doxorubicin, dacarbazine, dexamethasone) to eBEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisone) in a PET adapted approach. Separate analyses of the co-primary endpoints for tolerability and efficacy demonstrated a significant and relevant reduction in treatment-related morbidity (TRMB) and non-inferiority of PFS, respectively. Here, we report the first combined comprehensive analysis of the primary endpoints of the HD21 trial. METHODS This international open-label phase III trial included adult patients aged ≤ 60 yrs with AS-cHL. Patients were randomized in a 1:1 ratio to PET2-guided 4-6 21-day cycles of either eBEACOPP or BrECADD. PET2 and PFS events were assessed by blinded panel review. At a planned interim analysis at 36 months follow-up, the efficacy endpoint PFS was determined in the ITT cohort comprising 1,482 patients (eBEACOPP n=740, and BrECADD n=742) while the safety endpoint TRMB was determined in 1,470 patients (BEACOPP n=732, and BrECADD n=738). Subgroup analyses were calculated with 95% confidence intervals (Cis). The trial was registered at clinicaltrials.gov (NCT02661503) and conducted according to ICH-GCP guidelines. RESULTS Between July 2016 and August 2020, we enrolled 1,500 patients from 9 countries across 233 trial sites. Actual median follow-up for this analysis was 40 months. Baseline characteristics were well balanced between treatment arms, median age was 34 yrs (range 18-61), and 47% were high-risk (international prognostic index IPS ≥ 3). Overall, the relative risk for a TRMB event was 0.72 (95% CI, 0.65-0.79) in favor of BrECADD. Subgroup analyses confirmed a consistent, highly significant TRMB benefit in all relevant subgroups. Dose reductions were required less frequently with BrECADD than with eBEACOPP (figure 1); full dose treatment at cycle 4 was administered in 58.5% of patients in the eBEACOPP group compared to 77.8% in the BrECADD group. In PET2-positive patients at cycle 6, full dose treatment was received by 42.5% in the eBEACOPP group versus 67.3% in the BrECADD group. Most frequent reasons for dose reductions were leukopenia for eBEACOPP (in 33.7% of patients) and thrombocytopenia for BrECADD (in 23.1 % of patients). 59% of patients achieved a PET2-negative response and were treated with a total of 4 cycles in each group; conversely, 41% of patients were PET2-positive and received 6 cycles. At the end of treatment with either 4 or 6 cycles, a complete metabolic response was seen in 80% and 82% of patients in the eBEACOPP and BrECADD cohorts, respectively. The 3-yr PFS was 94.9% for BrECADD (95% CI 93.5% - 96.7%), and 92.3% for eBEACOPP (95% CI 90.3% - 94.3%), with a corresponding HR of 0.63 (95% CI 0.42-0.94). A HR favoring BrECADD was consistently observed across all relevant subgroups (figure 2). Notably, HRs favoring BrECADD were generally lower in lower-risk cohorts including IPS (0, 1; 2, 3; 4-7: HR 0.45, 0.59, 0.87, respectively), stage (Ann-Arbor stage II, III, IV: HR 0.35, 0.6, 0.78, respectively), or PET-2 response (negative versus positive, HR 0.4, 95% CI 0.21-0.76 vs 0.78, 95% CI 0.44-1.38). Corresponding 3-yr PFS rates for BrECADD versus eBEACOPP were 97.1% (95% CI 95.5% - 98.7%) versus 93.6% (95% CI 91.3% - 95.9%) for PET2-negative patients and 93.5% (95% CI 90.6% - 96.5%) versus 90.6% (95% CI 87.1% - 94.1%) for PET2-positive patients, respectively. CONCLUSION With the novel BrECADD regimen, we observed the highest 3-yr PFS rates reported to date in a randomized clinical trial in advanced-stage cHL. Our analyses suggest that the unexpectedly high and improved efficacy of the new BrECADD regimen compared to eBEACOPP is a direct consequence of its improved tolerability and deliverability. Importantly, while the larger patient cohort of PET2-negative patients achieves a very high 3-yr PFS of 97% with a very short and safe 12-week treatment, this benefit was also observed for PET2-positive patients. In conclusion, the optimized risk-benefit ratio of the BrECADD regimen combined with the individualized PET2-guided treatment duration sets a new benchmark for the treatment of adult patients with newly diagnosed advanced stage cHL

A Prospective, Phase-II Study to Evaluate the Efficacy and Safety of Obinutuzumab, Ibrutinib, and Venetoclax (GIVeRS) in Patients with Richter's Syndrome

Background: Richter's syndrome (RS) is an aggressive histologic transformation of chronic lymphocytic leukemia (CLL), most commonly to diffuse large B-cell lymphoma (DLBCL). RS is characterized by a rapid clinical course, low responses to therapy, and poor long-term survival. Chemoimmunothreapy for RS achieves overall response rates of 40% to 60%, and median progression-free survival (PFS) and overall survival (OS) of 3 to 10 months and 6 to 21 months, respectively. More recently, single targeted agents of either ibrutinib or venetocolax have been shown some clinical activity in RS. Furthermore, ibrutinib combined with venetoclax with or without anti-CD20 antibodies has a synergistic activity in CLL, resulting in deep and prolong responses along with a good safety profile. Methods: This is a prospective phase 2, open-label, non-randomized, single-arm, multi-center study aimed to assess the efficacy and safety of ibrutinib, venetoclax, and obinutuzumab in treatment-naïve or relapsed/refractory patients with biopsy-confirmed RS to DLBCL (NCT04939363). The experimental regimen consisted of 12 months of fixed-duration treatment with obinutuzumab, ibrutinib, and venetoclax. Obinutuzumab was administered at a dose of 100 mg intravenously on day 1, 900 mg on day 2, and then 1000 mg on day 8 and 15 of cycle 1. On day 1 of the subsequent five cycles, obinutuzumab at a dose of 1000 mg was administered. Ibrutinib was administered at a dose of 560mg orally daily initiated together with the first obinutuzumab infusion on day 1 of cycle 1 and was continued throughout the 12 treatment 28-day cycles. Venetoclax was given at a dose of 400 mg orally daily for 12 treatment cycles after an accelerated ramp-up phase from day 15 in cycle 1. The primary endpoint was investigator-assessed overall response rate (ORR) defined as the proportion of patients who achieve complete metabolic response (CR) and partial metabolic response (PR) determined by PET-CT imaging at 6 months per Lugano 2014 criteria. Other key endpoints included; investigator-assessed ORR at 3 and 12 months, PFS, Duration of response (DOR), OS, and safety. Results: From August 2021 until the data cut-off on July 20, 2023, a total of 10 patients with RS were enrolled. Median age was 76.0 (range, 62‒88) years and 70% were male. Six patients were treatment-naïve, 4 had relapsed/refractory RS, 50% had extra-nodal disease, 70% had elevated LDH, 70% were double or triple expressors, and the median number of prior therapies among the R/R patients was 1 (Table 1). Median follow-up was 255 days (95% CI, 158.7-351.3), median treatment duration was 160 days (range: 29-362) and treatment is still ongoing in 3 patients. At 3 and 6 months, the ORRs were 70.0% (7/10) and 22.2% (2/9), respectively, and CR rates (CRRs) were 40.0% (4/10) and 11.1% (1/9), respectively. At the data cutoff, 6/10 (60.0%) patients progressed and 5/10 (50.0%) died. The median PFS was 162 days (95% CI, 66.9-257.1), median DOR 272 days, and median OS was 228 days (95% CI: 184.2-271.8). The causes of death included RS in 2 patients and one case each of Covid-19, secondary malignancy, and general deterioration. Most common related treatment-emergent AEs (TEAEs) of all grades were neutropenia 40%, thrombocytopenia 50%, diarrhea 40%, and skin rash 50%, 2 patients developed Covid-19 who recovered during the protocol. None of the patients developed tumor lysis syndromes. Conclusions: In patients with RS triplet treatment with ibrutinib, venetoclax, and obinutuzmab was well tolerated, achieved high rates of early metabolic response (ORR-70% and CRR-40%) at 3 months. Given the high early response rate but subsequent progression, this triplet therapy may serve as a bridge to consolidation with cellular therapy.