Median Number Of Prior Therapies Research Articles

17 CDK4/6 inhibition with Abemaciclib in in patients (pts) with previously treated advanced renal carcinoma (RCC)

Abstract Background Preclinical data suggests rationale for CDK4/6 alone and in combination with HIF-2 inhibitors; single agent activity for CDK4/6 inhibitors in RCC has not been reported. Abemaciclib is an oral CDK4/6 inhibitor approved in combination with hormonal therapy for metastatic breast cancer. In our phase 1b clinical trial (NCT04627064), we investigated the safety and clinical efficacy of abemaciclib monotherapy in pts with advanced pretreated RCC with clear cell component. Methods In this single center trial, adult pts with advanced RCC with a clear cell component and ECOG status of ≤1 progressing after at least one prior regimen including immunotherapy and a VEGF TKI received abemaciclib 200 mg twice daily in 4-week cycles until progression or unacceptable toxicity. Primary objective was to evaluate the objective response rate (ORR) of abemaciclib with secondary endpoint of safety. First imaging was performed after 2 cycles. Response assessed per RECIST 1.1 and toxicity per CTCAE v5.0. Results 11 pts (10 clear cell RCC and 1 translocation RCC) were enrolled between 12/31/2020 and 10/03/2023. Median age was 62 years (range 54-68) with 18% (n=2) showing sarcomatoid features. 73% (n=8) had IMDC intermediate risk disease and one patient had translocation RCC (tRCC) with a clear cell component. Median number of prior therapies was 4 (range 1-9). Seven patients received 2 cycles and 4 patients received < 2 cycles. ORR was 0% (0/11; 8 progressive disease, 1 stable disease in tRCC stopping for clinical progression, 2 pts not evaluable with clinical progression). 27% (n=3) experienced grade ≥3 treatment-related adverse events (diarrhea n=1, nausea n=1, neutropenia n=1). Conclusions In pts with heavily pretreated RCC, abemaciclib had manageable toxicity profile but no clinically meaningful activity as monotherapy. This data will offer important insight into interpretation of results for ongoing trials exploring CDK4/6 inhibition in combination with HIF-2 inhibitors.

The PI3Kδ inhibitor zandelisib on intermittent dosing in relapsed/refractory follicular lymphoma: Results from a global phase 2 study.

In this global phase 2 study in patients with relapsed/refractory follicular lymphoma (FL), zandelisib was administered on intermittent dosing to mitigate immune-related adverse events and infections that have been reported with oral PI3Kδ inhibitors administered daily continuously. Eligible patients with measurable disease and progression after at least twoprior therapies were administered zandelisib until disease progression or intolerability. The primary efficacy endpoint was objective response rate (ORR) and the key secondary efficacy endpoint was duration of response (DOR). We report on 121 patients with FL administered zandelisib on intermittent dosing after 8 weeks of daily dosing for tumor debulking. The median number of prior therapies was 3 (range, 2-8) and 45% of patients had refractory disease. The ORR was 73% (95% confidence interval [CI], 63.9-80.4), the complete response (CR) rate was 38% (95% CI, 29.3-47.3), and the median DOR was 16.4 months (95% CI, 9.5-not reached). With a median follow-up of 14.3 months (range, 1-30.5), the median progression-free survival was 11.6 months (95% CI, 8.3-not reached). Twenty-one patients (17%) discontinued therapy due to an adverse event. Grade 3-4 class-related toxicities included 6% diarrhea, 5% lung infections, 3% colitis (confirmed by biopsy or imaging), 3% rash, 2% AST elevation, and 1% non-infectious pneumonitis. Zandelisib achieved a high rate of durable responses in heavily pretreated patients with relapsed/refractory FL. The intermittent dosing resulted in a relatively low incidence of severe class-related toxicities, which supports the evaluation of zandelisib as a single agent and in combination with indolent B-cell malignancies.

Phase I Trial of Brentuximab Vedotin Plus Cyclosporine in Relapsed/Refractory Hodgkin Lymphoma

IntroductionBV is an antibody-drug conjugate directed against CD30 and is safe and effective in relapsed/refractory (R/R) Hodgkin lymphoma (HL). Most patients with r/r cHL respond well to BV monotherapy; however, the large of majority of them eventually progress on this drug, and BV-resistant HL remains an unmet need. Preclinical data suggest that BV resistance is mediated at least in part by increased drug efflux associated with increased expression of multidrug resistance pump 1 (MDR1) while CD30 expression appears to be preserved in BV resistant cell lines and patient samples. We conducted a phase 1 study evaluating BV + cyclosporine (CsA) in BV-refractory HL and previous reported results in the dose finding cohort. Here we report the final results from the phase 1 study. MethodsThis was a phase I trial of BV + CsA in patients with r/r HL with dose-finding and dose escalation cohorts. Eligibility criteria included age ≥ 18 years with r/r HL after at least 1 prior line of therapy. Treatment consisted of 1.8 mg/kg BV intravenously on day 1 and CsA 5 to 7.5 mg/kg PO twice daily on days 1 to 5; cycles were 21 days long. Patients in the expansion cohort had to have cHL refractory to BV. The primary objectives were to evaluate safety and tolerability and to determine MTD of BV + CsA; the secondary objective was to determine efficacy of this combination. Results29 patients were enrolled onto the study, 14 in the dose finding cohort and 15 in the dose expansion BV refractory cohort. Study accrual was terminated before target accrual due to unacceptable toxicity. 62% of patients were male, and the median age was 36 years (range: 20-69). The median number of prior therapies was 5 (range: 3-12); all patients had prior BV, and 93% had PD-1 directed therapy, and 93% were BV-refractory. Of 22 evaluable patients, CR rate was 27% and ORR 64%; median DOR 4.9 months. Treatment-related deaths occurred in 3 patients, and another patient died during cycle 1 due to cardiac arrest deemed unlikely related to be protocol therapy. All grade GI toxicity was seen in 90% of patients (G3+ in 24%); other common adverse events were nausea (90%), hypertension (90%), nausea (90%), hypertension (90%), anemia (86%), fatigue (76%), neutropenia (76%), leukopenia (76%), hypomagnesemia (76%), anorexia (66%), and hyponatremia (66%). DiscussionBV + CsA demonstrated modest activity in BV-refractory r/r HL; however, toxicity is substantial.

Phase I safety and preliminary efficacy of PM1009, a bispecific antibody targeting TIGIT and PVRIG, in patients with advanced solid tumors.

e14695 Background: PM1009 is an anti-TIGIT x PVRIG bispecific antibody containing a fully human anti-TIGIT IgG1 fused with a fully human anti-PVRIG scFv at the C terminus. PM1009 can potently block the TIGIT/CD155/CD112 and PVRIG/CD112 signaling pathways, and supports the depletion of TIGIT-positive Treg cells in the tumor microenvironment through FcγR engagement. This leads to the enhancement of T cell and NK cell activity towards the killing of tumor cells. PM1009 showed robust in vitro and in vivo efficacy with good safety in preclinical studies. Methods: This is the first-in-human study of PM1009, which includes a dose escalation stage (accelerated titration & 3+3 design) followed by dose expansion. In the dose escalation stage, PM1009 was administered as flat doses of 120, 300, 600 and 1200 mg for DLT evaluation after 3 weeks followed by administration Q2W. Primary endpoints were safety and tolerability, and the secondary endpoints were PK, ORR and DCR (per RECIST 1.1). Results: As of February 1, 2024, a total of 12 patients were enrolled for dose escalation and received at least one dose of PM1009, with 3 patients in each of the 120, 300, 600 and 1200 mg dose-levels. Median number of prior therapies was 5 lines (range 1- 9). No DLTs were observed up to 1200 mg. Any-grade TRAEs occurred in 11 patients (91.7%), and ≥ Grade 3 TRAEs occurred in 2 patients (16.7%). Any-Grade irAEs occurred in 7 patients (58.3%), and ≥ Grade 3 irAEs occurred in 1 patient (8.3%). Treatment interruption due to TRAE occurred in 2 patients (16.7%), with infusion related reaction (the main symptom was nausea, and the single infusion was eventually completed), and neutrophil count decrease respectively. Treatment discontinuation due to TRAE occurred in 2 patients (16.7%), with acute myocardial infarction, and neutrophil count decrease respectively. The most common TRAEs were ALP elevation (33.3%) and AST elevation (25.0%). 12 patients completed at least one tumor evaluation. The DCR per RECIST 1.1 by investigator was 33.3% (4/12; 95% CI: 9.92 - 65.11), best overall response was SD. Pharmacokinetics were dose-proportional with a terminal half-life of 5.2-7.4 days across the dose range of 120-1200 mg. Conclusions: PM1009 was well-tolerated up to 1200 mg with signs of anti-tumor activity. These findings support further clinical investigation of PM1009 especially for the combination with chemotherapy or PD-1/L1-based checkpoint inhibitors. Clinical trial information: NCT05607563 .

A pilot study of axicabtagene ciloleucel (axi-cel) for relapsed/refractory primary and secondary central nervous system lymphoma (PCNSL and SCNSL).

2006 Background: Prognosis of patients with relapsed/refractory (R/R) CNSL is poor with no standard of care treatment options. Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy axicabtagene ciloleucel (axi-cel) has shown efficacy in R/R systemic large B-cell lymphoma (LBCL) and could be considered for R/R CNSL. Methods: We conducted a pilot study of axi-cel in patients with R/R CNS LBCL. No bridging therapy except corticosteroids was allowed after enrollment. Ommaya reservoir was placed before infusion. Patients underwent lymphodepletion with fludarabine and cyclophosphamide followed by axi-cel dosing of 2x106 cells/kg intravenous infusion. The study enrolled 18 patients, of whom the first 6 patients were observed for treatment-limiting toxicities (TLTs). Primary endpoint was safety, measured by rate of TLTs and grade 3+ adverse events (AEs). Secondary endpoints included objective response rate (ORR), complete response (CR) rate, duration of response (DOR), progression-free survival (PFS) and overall survival (OS). Exploratory analyses include paired peripheral blood (PB) and CSF analyses for axi-cel pharmacokinetics, pharmacodynamics, flow cytometry, single-cell RNA-Seq. Results: We report the results of the entire cohort of 18 patients (13 PCNSL, 4 SCNSL, 1 concurrent systemic & ocular L) enrolled. Median age was 62 years (33-80), 8/18 were women. Median number of prior therapies was 3 (1-7). No TLTs were observed; 16/18 (89%) patients developed cytokine release syndrome/CRS (grade 3+, 0%); 8/18 (44%) developed immune effector cell-associated neurologic syndrome/ICANS, 5/18 (28%) grade 3+. Two patients developed Ommaya-related meningitis requiring explant with recovery. One patient had grade 3 seizures that resolved with anti-epileptic agents. The ORR was 94% (17/18); 67% CR (12/18). The median time to best response was 3 months. As of January 25, 2024, the median follow up was 24.2 months, median DOR 13.4 months and 9 patients had progressed. The median PFS was 14.3 months (95% CI: 6.3-NR) and median OS, 26.4 months (95% CI: 11.2-NR). Seven patients have died, all from disease progression. At the time of presentation, there will be a minimum follow-up of 12 months. Correlative data on all 18 patients will be presented at the meeting. Axi-cel pharmacokinetics in the first 12 CNSL patients was similar to that previously reported for DLBCL patients without CNS involvement in ZUMA-1 and ZUMA-7. Patients with CR demonstrated increased peak levels of pro-inflammatory cytokines. CSF CAR T cells exhibit Type I interferon (IFN) transcriptomic signature compared to proliferative signature in blood. Conclusions: Axi-cel was safe and well-tolerated in CNSL patients with encouraging efficacy and median PFS and durability of response of more than 1 year. There was no apparent additional risk of adverse neurologic events including ICANS from axi-cel. Clinical trial information: NCT04608487 .

A Phase I Trial Evaluating the Addition of Lenalidomide to Patients with Relapsed/Refractory Multiple Myeloma Progressing on Ruxolitinib and Methylprednisolone.

Ruxolitinib (RUX), an orally administered selective Janus kinase 1/2 inhibitor, has received approval for the treatment of myelofibrosis, polycythemia vera, and graft-versus-host disease. We have previously demonstrated the anti-multiple myeloma effects of RUX alone and in combination with the immunomodulatory agent lenalidomide (LEN) and glucocorticosteroids both pre-clinically and clinically. This study aims to evaluate whether LEN can achieve clinical activity among patients with multiple myeloma progressing on the combination of RUX and methylprednisolone (MP). In this part of a phase I, multicenter, open-label study, we evaluated the safety and efficacy of RUX and MP for patients with multiple myeloma with progressive disease who had previously received a proteasome inhibitor, LEN, glucocorticosteroids, and at least three prior regimens; we also determined the safety and efficacy of adding LEN at the time of disease progression from the initial doublet treatment. Initially, all subjects received oral RUX 15 mg twice daily and oral MP 40 mg every other day. Those patients who developed progressive disease according to the International Myeloma Working Group criteria then received LEN 10 mg once daily on days 1-21 within a 28-day cycle in addition to RUX and MP, which were administered at the same doses these patients were receiving at the time progressive disease developed. Twenty-nine subjects (median age 64 years; 18 [62%] male) were enrolled in this part of the study and initially received the two-drug combination of RUX and MP. The median number of prior therapies was six (range 3-12). The overall response rate from this two-drug combination was 31% and the clinical benefit rate was 34%. The best responses were 1 very good partial response, 8 partial responses, 1 minor response, 12 stable disease, and 7 progressive disease. The median progression-free survival was 3.5 months (range 0.5-36.2months). The median time to response was 3.0 months. The median duration of response was 12.5 months (range 2.8-36.2 months). Twenty (69%) patients whoshowed progressive disease had LEN added to RUX and MP; all patients had prior exposure to LEN and all but one patient was refractory to their last LEN-containing regimen. After the addition of LEN, the overall response rate was 30% and the clinical benefit rate was 40%. The best responses of patients following the addition of LEN were 2 very good partial responses, 4 partial responses, 2 minor responses, 8 stable disease, and 4 progressive disease. The median time to response was 2.6 months (range 0.7-15.0 months). The median duration of response was not reached. The median progression-free survival following the addition of LEN was 3.5 months (range 0.3-25.9 months). For patients with multiple myeloma, treatment with RUX and MP is effective and well tolerated, and LEN can be used to extend the benefit of this RUX-based treatment. This study is registered with ClinicalTrials.gov, NCT03110822, and is ongoing.

Efficacy, Safety, and Tolerability of Tivozanib in Heavily Pretreated Patients With Advanced Clear Cell Renal Cell Carcinoma.

Tivozanib has been approved as a third-line or later therapy for advanced renal cell carcinoma based on the TIVO-3 trial, which was conducted before immune checkpoint therapies (ICT), cabozantinib, and lenvatinib/everolimus became incorporated in the current sequential treatment paradigm for advanced clear cell RCC (ccRCC). We performed a retrospective study of patients with advanced ccRCC treated with tivozanib at MD Anderson Cancer Center during 6/2021-7/2023. A blinded radiologist assessed tumor response by RECIST v1.1. We assessed overall response rate (ORR), clinical benefit rate (CBR) [percentage of all treated patients who achieved radiologic response or stable disease (SD) for ≥ 6 months], progression-free survival (PFS), overall survival (OS), and safety. Of 30 analyzed patients, 23% had performance status ≥ 2; 47% had International Metastatic RCC Database Consortium (IMDC) poor-risk disease. Median number of prior therapies was 4 (range 1-8). All patients received prior ICT, 87% cabozantinib and 60% lenvatinib ± everolimus. Of 26 evaluable patients, 2 patients had confirmed partial response (ORR 7.7%); 5 patients had SD for ≥ 6 months (CBR 23.3%). Median PFS was 3.8 months (range 0.7-13.9); median OS was 14.1 months (range 0.3-28.5). Fifteen patients (50%) had ≥ 1 treatment-related adverse event (TRAE). There were 6 grade ≥ 3 TRAEs [hypertension, congestive heart failure (3), mucositis, and GI perforation (grade 5)]. In this cohort of heavily pretreated patients with advanced ccRCC, tivozanib yielded a modest clinical benefit in a minority of patients who received prior ICT, cabozantinib, and lenvatinib ± everolimus. TRAEs were consistent with previously published reports.

A phase 2 study of AZD4635 in combination with durvalumab or oleclumab in patients with metastatic castration-resistant prostate cancer

BackgroundInhibition of the adenosine 2A receptor (A2AR) diminishes the immunosuppressive effects of adenosine and may complement immune-targeting drugs. This phase 2 study evaluated the A2AR antagonist AZD4635 in combination with durvalumab or oleclumab in patients with metastatic castration-resistant prostate cancer.MethodsPatients with histologically/cytologically confirmed disease progressing within 6 months on ≥ 2 therapy lines were randomly assigned to either Module 1 (AZD4635 + durvalumab) or Module 2 (AZD4635 + oleclumab). Primary endpoints were objective response rate per RECIST v1.1 and prostate-specific antigen (PSA) response rate. Secondary endpoints included radiological progression-free survival (rPFS), overall survival, safety, and pharmacokinetics.ResultsFifty-nine patients were treated (Module 1, n = 29; Module 2, n = 30). Median number of prior therapies was 4. One confirmed complete response by RECIST (Module 1) and 2 confirmed PSA responses (1 per module) were observed. The most frequent adverse events (AEs) possibly related to AZD4635 were nausea (37.9%), fatigue (20.7%), and decreased appetite (17.2%) in Module 1; nausea (50%), fatigue (30%), and vomiting (23.3%) in Module 2. No dose-limiting toxicities or treatment-related serious AEs were observed. In Module 1, AZD4635 geometric mean trough concentration was 124.9 ng/mL (geometric CV% 69.84; n = 22); exposures were similar in Module 2. In Modules 1 and 2, median (95% CI) rPFS was 2.3 (1.6 –3.8) and 1.5 (1.3– 4.0) months, respectively. Median PFS was 1.7 versus 2.3 months for patients with high versus low blood-based adenosine signature.ConclusionIn this heavily pretreated population, AZD4635 with durvalumab or oleclumab demonstrated minimal antitumor activity with a manageable safety profile. Clinical Trial.gov identifier: NCT04089553.

Phase II Clinical Trial of Trametinib and Low-Dose Dabrafenib in Advanced, Previously Treated BRAFV600/NRASQ61 Wild-Type Melanoma (TraMel-WT)

PURPOSE Patients with BRAF V600/ NRAS Q61 wild-type melanoma who progress after immune checkpoint inhibitors (ICIs) have a poor prognosis. MEK inhibition has shown activity in this patient population but is associated with treatment-limiting skin toxicity. Combining a BRAF inhibitor with a MEK inhibitor is associated with less skin toxicity. METHODS This phase II trial investigated trametinib (2 mg once daily) in patients with advanced BRAF V600/ NRAS Q61 wild-type, ICI-refractory melanoma. In case of treatment-limiting skin toxicity, low-dose dabrafenib (50 mg twice daily) was added to trametinib. After a trial amendment, both drugs were combined up-front. The confirmed objective response rate (cORR) served as the primary end point. RESULTS Twenty-four patients were included (50% male; median age 57 years; 92% Eastern Cooperative Oncology Group Performance Status 0-2; 75% stage IV-M1c/stage IV-M1d; median number of prior therapies: two [range, 1-5]). Three patients were enrolled before and 21 patients after the amendment, respectively. Seven confirmed and one unconfirmed partial responses (PRs) were observed (cORR, 29.2%). The median duration of response was 16.6 weeks (95% CI, 5.5 to 27.7). Stable disease (SD) was the best response in an additional five patients. Among the responding patients, genetic alterations causing mitogen-activated protein kinase (MAPK) pathway activation were documented in six patients. The disease control rate in patients with MAPK pathway–activating alterations was 64.3% (five confirmed PR, one unconfirmed PR, and three SD). The median progression-free survival was 13.3 weeks (95% CI, 3.5 to 23.1), and the median overall survival was 54.3 weeks (95% CI, 37.9 to 70.6). Adding low-dose dabrafenib to trametinib effectively mitigated or prevented treatment-limiting trametinib-related skin toxicity. CONCLUSION The combination of trametinib plus low-dose dabrafenib demonstrated encouraging efficacy and effective mitigation of skin toxicity in patients with advanced, ICI-pretreated BRAF V600/ NRAS Q61 wild-type melanoma patients. MAPK pathway–activating alterations hold promise as a predictive biomarker.

Real-world evidence of obinutuzumab and venetoclax in previously treated patients with chronic lymphocytic leukemia or small lymphocytic lymphoma

Venetoclax-obinutuzumab (Ven-O) is frequently administered off-label in relapsed/refractory (r/r) CLL/SLL where venetoclax-rituximab is the approved regimen. We conducted this retrospective, real-world study to evaluate Ven-O in r/r CLL/SLL. Between 7/2019 and 6/2022, 40 patients with r/r CLL/SLL on Ven-O were included. The median age was 72, 28.2% had TP53 mutation and/or 17p deletion, median number of prior therapies was 1 (range, 1–6), and 55% had prior BTK inhibitor exposure. The overall response rate was 90% (complete response [CR] or CR with incomplete marrow recovery in 27.5% and partial response in 62.5%) of patients, and the 2-year progression-free survival was 81.2% (95% CI, 69.5–94.8). Therapy was well tolerated. No laboratory or clinical TLS occurred with venetoclax (Howard criteria). One (3%) patient experienced laboratory TLS with obinutuzumab initiation. In summary, this retrospective cohort study demonstrated that Ven-O achieves frequent, durable responses and can be safely administered in r/r CLL/SLL.

A phase 1/2 study of mini-hyper-CVD plus venetoclax in patients with relapsed/refractory acute lymphoblastic leukemia

AbstractPreclinical studies suggest that Bcl-2 inhibition with venetoclax has antileukemic activity in acute lymphoblastic leukemia (ALL) and may synergize with conventional chemotherapy. We designed a phase 1/2 clinical trial to evaluate the safety and efficacy of low-intensity chemotherapy in combination with venetoclax in adults with relapsed or refractory ALL. Patients received the mini-hyper-CVD regimen (dose-attenuated hyperfractionated cyclophosphamide, vincristine, and dexamethasone alternating with methotrexate and cytarabine) in combination with venetoclax (200 mg or 400 mg daily) on days 1 to 14 in cycle 1 and on days 1 to 7 in consolidation cycles. Twenty-two patients were treated. The median number of prior therapies was 2 (range, 1-6). Thirteen patients (59%) had undergone prior allogeneic stem cell transplant (allo-SCT), and 7 of 18 patients (39%) with B-cell ALL had previously received both inotuzumab ozogamicin and blinatumomab. The recommended phase 2 dose of venetoclax in the combination regimen was 400 mg daily. The composite complete remission (CR) and CR with incomplete hematologic recovery (CRi) rate was 57% (CR, 43%; CRi, 14%), and 45% of responders achieved measurable residual disease negativity by multiparameter flow cytometry. Four patients proceeded to allo-SCT. The median duration of response was 6.3 months. The median overall survival was 7.1 months, and the 1-year overall survival rate was 29%. The most common grade ≥3 nonhematologic adverse events were infection in 17 patients (77%) and febrile neutropenia in 4 patients (18%). Overall, the combination of mini-hyper-CVD plus venetoclax was active in heavily pretreated relapsed/refractory ALL. Further development of venetoclax-based combinations in ALL is warranted. This trial is registered at www.clinicaltrials.gov as #NCT03808610.

Abstract B046: A first-in-human Phase 1a/b of PEP-010, a proapoptotic bifunctional peptide, administered as single agent and in combination with paclitaxel in patients with recurrent and/or metastatic solid cancer: results from the dose escalation study

Abstract Background: PEP-010 is a first-in-class bifunctional peptide that penetrates cells and specifically disrupts the interaction between Caspase9 and PP2A, two proteins involved in the apoptotic cascade, leading to Caspase9-dependent apoptosis in cancer cells. Safety, PK, and preliminary anti-tumor activity from the dose escalation part of a Phase 1a/b study of PEP-010 as a monotherapy and in combination with paclitaxel (P) in recurrent and/or metastatic solid cancer are presented. Methods: PEP-010 was administered as a 3-hour intravenous weekly infusion on 3 consecutive days in patients (pts) with advanced cancer ineligible for standard therapy, in monotherapy (Arm A) or in combination with weekly P (Arm B) for pts eligible for P. In Arm A, pts were enrolled into 8 dose cohorts starting at 0.15 mg/kg up to 15 mg/kg, using an accelerated titration design (first 4 dose levels (DLs)), followed by a 3+3 design. In Arm B, 5 DLs of PEP-010 combined with weekly P (80mg/m²) were explored. The primary objective was the determination of the maximum tolerated dose (MTD) and the recommended phase 2 dose (RP2D) of PEP-010 in both arms, based on occurrence of dose-limiting toxicities (DLTs). Secondary objectives were the safety and tolerability profile, PK and preliminary antitumor activity assessed by RECIST1.1. Results: At data cutoff (March 7, 2023), 19 (Arm A) and 15 (Arm B) pts received PEP-010 across 8 and 3 DLs, respectively. Median age was 57 [32-78] years and 56% were female. Median number of prior therapies was 6 [2-13]. A DLT (Grade 2 infusion-related reaction (IRR)) was observed in 1 pt in Arm A at DL 8 (15 mg/kg). In Arm B, 3 pts experienced a DLT at DL 5 mg/kg: 1 Grade 4 neutropenia and 2 IRR (inacceptable Grade 2 and 4). All DLTs led to permanent treatment discontinuation. MTD was defined as 15 mg/kg in Arm A and 2.5 mg/kg in Arm B. Most common adverse events (AE) related to PEP-010 included asthenia (26.5%) and IRR (14.7%) whereas most common AEs related to P included anemia (66.7%), peripheral neuropathy (33.3%), neutropenia (20%), onychopathy (20%), and diarrhea (20%). Median time on treatment was 5.1 weeks [2.1-25.3] in Arm A and 5.3 [3-18] in Arm B. In Arm A, for 7 pts (36.8%) a stable disease (SD) was observed for a median of 2.8 months [0.6-4.5]. In Arm B, 4 (26.7%) confirmed partial responses were observed in pts with ovarian, pancreatic and thyroid adenocarcinomas, and squamous cell lung carcinoma, and 2 pts (13.3%) had SD for a median of 4 months [2.7-9.6]. PK data indicated a proportionally dose-related increase of systemic exposure to PEP-010. No significant accumulation of PEP-010 over time or impact of P combination was observed. Conclusions: Data from the Escalation Part of the Phase 1a/b clinical trial showed an acceptable safety profile of PEP-010 in monotherapy. In combination, the dose of PEP-010 could not be escalated to the same level because of IRR. Preliminary antitumoral activity was observed with PEP-010 in combination with P including in pts who had previously received taxanes. Further clinical development is warranted. Citation Format: Pauline Du Rusquec, Elodie Coquan, Frederique Berger, Keyvan Rezai, Pierre-Emmanuel Brachet, Sophie Postel-Vinay, Zahra Castel-Ajgal, Gregoire Marret, Marie-Paule Sablin, Segolene Hescot, Raphael Sanchez, Anne-Claire Coyne, Claire Bertrand, Clementine Bouchez, Elsa Lafitte, Lucas Frezouls, Carole Mardesson, Abdelkrim Taamma, Chantal Krezel, Laura Dadon, Christophe Le Tourneau. A first-in-human Phase 1a/b of PEP-010, a proapoptotic bifunctional peptide, administered as single agent and in combination with paclitaxel in patients with recurrent and/or metastatic solid cancer: results from the dose escalation study [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B046.

Abstract PR012: Novel strategy for RAS-pathway targeting: Initial results from a phase 1b/2 clinical trial of the oral HDAC inhibitor bocodepsin (OKI-179) combined with binimetinib in patients with RAS-pathway mutated solid tumors and NRAS-mutated melanoma

Abstract Background: Activating RAS pathway mutations occur in > 30% of human cancers, including NRAS mutations in 15-20% of advanced melanoma. MEK inhibitors have modest single agent activity in NRAS-mutated melanoma, showing a 15% overall response rate and 2.8 month progression free survival. Bocodepsin (OKI-179) is a novel Class I-selective, oral histone deacetylase inhibitor (HDACi). The combination of bocodepsin and binimetinib is preferentially synergistic in RAS pathway mutated tumor models, leading to the unique mechanism of double strand DNA breaks and cellular apoptosis. Here we present the initial results of the Nautilus phase 1b/2 trial of bocodepsin and binimetinib (NCT05340621). Materials and Methods: In Phase 1b, patients with previously treated advanced solid tumors with any activating RAS pathway mutation were treated with binimetinib oral 45 mg twice daily with bocodepsin 200 mg (cohort 1) or 300 mg (cohort 2) oral daily 4 days on 3 days off in 28-day cycles. In Phase 2, patients with NRAS-mutated melanoma previously treated with immunotherapy were treated with bocodepsin 300 mg with binimetinib in a Simon optimal 2-stage study with a primary endpoint of objective response rate. Secondary endpoints included safety and PK. Results: As of July 6, 2023, 14 patients were enrolled in Phase 1b in 2 cohorts and across multiple tumor types (colorectal, n=4; melanoma, n=3; NSCLC, n=2; pancreatic, n=2; other, n=3) and RAS-pathway mutations (KRAS, n=9; NRAS, n=3; BRAF, n=1; NF1, n=1). The median age was 70 (41-76) and median number of prior therapies was 6 (1-13). No DLTs were observed. Bocodepsin 300 mg was identified as the RP2D in combination with standard dose binimetinib. The most common treatment-emergent adverse events were consistent with either binimetinib or bocodepsin alone known adverse events and included diarrhea (N=11, 78.57%), nausea (N=9, 64.29%), anemia (N=8, 57.14%), and dermatitis acneiform (N=8, 57.14%). The most common grade 3/4 events included anemia (N=4, 28.57%) and syncope (N=2, 14.29%). Of the 14 evaluable patients in Phase 1, the best response was partial response (PR) in 1 pt (NRAS-mutated melanoma) and stable disease (SD) in 6 pts, with a median time on study of 120 days (50-260). Phase 2 enrollment is ongoing. At the data cutoff, in the 9 response evaluable NRAS melanoma patients (between Ph1 and Ph2), 3 PR and 3 SD were observed. Conclusions: The combination of bocodepsin and binimetinib in patients with RAS-mutated advanced cancers is tolerable with manageable AEs. Initial response data in NRAS melanoma are supportive of potential combinatorial activity of binimetinib and bocodepsin. The data for Phase 2 will be updated at the time of presentation. Citation Format: Rodabe N Amaria, Herbert Duvivier, Katy Tsai, Robert Galamaga, Parisa Momtaz, Evan Pisick, Natalie Langr, Harish Dave, Duncan Walker, Jennifer Diamond, Kevin Litwiler, Ryan Sullivan. Novel strategy for RAS-pathway targeting: Initial results from a phase 1b/2 clinical trial of the oral HDAC inhibitor bocodepsin (OKI-179) combined with binimetinib in patients with RAS-pathway mutated solid tumors and NRAS-mutated melanoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr PR012.

Abstract PR014: Preliminary safety and anti-tumor activity of RMC-6291, a first-in-class, tri-complex KRASG12C(ON) inhibitor, in patients with or without prior KRASG12C(OFF) inhibitor treatment

Abstract Background RMC-6291 is a potent, covalent, orally bioavailable KRASG12C(ON) inhibitor that uses a novel tri-complex mechanism to selectively target the active, GTP-bound state of the oncogenic KRASG12C. In preclinical models, RMC-6291 achieved a superior response rate, deeper regressions and longer duration of response compared to the KRASG12C(OFF) inhibitor, adagrasib. Receptor tyrosine kinase (RTK) overexpression and/or hyperactivating alterations and new synthesis of KRASG12C(ON) have been identified as potential resistance mechanisms to KRASG12C(OFF) inhibitors. Preclinical modeling shows KRASG12C(ON) inhibitors retain potency in cells with RTK activation and further are expected to rapidly extinguish newly synthesized KRASG12C(ON). Methods Patients with previously treated, advanced KRASG12C-mutated solid tumors received escalating doses of RMC-6291. Doses included 50, 100, and 200mg once daily (QD) and 100, 200, 300, and 400mg twice daily (BID). Each cycle had 21 days, with efficacy assessed every 6 weeks. Additional patients were enrolled to backfill cohorts at dose levels that cleared dose-limiting toxicity evaluation to further characterize PK, safety, and anti-tumor activity of RMC-6291. Results As of August 8, 2023, 47 patients with KRASG12C mutated solid tumors were treated, and 35 remained on treatment. The median number of prior therapies was 3 (range, 1-7). RMC-6291 exhibited dose-dependent exposure with a median Tmax of 1.0 hour and terminal half-life of 1.8 hours. Modeling projected average target occupancy of ≥~90% at 100mg BID and above. Treatment-related adverse events (TRAEs) occurring in ≥10% of patients were nausea (34%), diarrhea (30%), QTc prolongation (21%), vomiting and fatigue (15% each). The most common Gr3 TRAEs were QTc prolongation reported in 5 patients (3 at 400mg BID, 1 at 300mg, 1 at 200mg BID). Only one out of these 5 patients had an average QTc interval >501ms. Most events of Gr3 QTc prolongation resolved to Gr1 or normal following dose interruption and/or reduction, and all 5 patients were asymptomatic and remained on treatment at a reduced dose. No treatment-related ≥Gr3 hepatotoxicity was observed. No patients experienced a treatment-related Gr4 or 5 AE, or a treatment-emergent AE that led to treatment discontinuation. Efficacy analysis was conducted in two dominant subgroups and included patients enrolled ≥8 weeks before data cutoff across all dose levels. The objective response rate was 57% (4/7; 3 confirmed) in NSCLC patients with recent prior KRASG12C(OFF) inhibitor treatment, and 44% (4/9; 3 confirmed) in CRC patients naive to KRASG12C(OFF) inhibitor treatment. Conclusions This preliminary data set shows promising anti-tumor activity of RMC-6291 in KRASG12C-mutated NSCLC with recent prior KRASG12C(OFF) inhibitor treatment, and in KRASG12C-mutated CRC naive to KRASG12C(OFF) inhibitor treatment. Tolerability was acceptable below 400mg BID, suggesting the potential for combination with standard therapy, including immunologic agents. Dose optimization is ongoing. Citation Format: Pasi A. Jänne, Frédéric Bigot, Kyriakos Papadopoulos, Lauriane Eberst, David Sommerhalder, Loic Lebellec, Pei Jye Voon, Bruna Pellini, Ewa Kalinka, Kathryn Arbour, Benjamin Herzberg, Valentina Boni, Stephanie Bordenave, Hyun Woo Lee, Sai I. Ou, Jonathan Wesley Riess, Joseph T. Beck, Mariano Ponz-Sarvise, Paolo Antonio Ascierto, Yoon Ji Choi, Michelle Yang, Lei Bao, Rakesh Raman, Luxi Yang, Yunming Mu, Sofia Wong, Richa Dua, Melissa Johnson. Preliminary safety and anti-tumor activity of RMC-6291, a first-in-class, tri-complex KRASG12C(ON) inhibitor, in patients with or without prior KRASG12C(OFF) inhibitor treatment [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr PR014.

Reduced Dose Brentuximab Vedotin for Mycosis Fungoides Appears to Prolong Response Duration By Balancing Efficacy and Tolerability

Introduction: Brentuximab vedotin (BV) is one of the most active systemic agents for treating mycosis fungoides (MF); however, treatment duration and the duration of response is frequently limited by the development of peripheral neuropathy (PN). In the phase III ALCANZA study of BV, 44/66 (67%) of patients (pts) treated with BV developed PN, including grade 2 (G2) in 32% and grade 3 (G3) in 10%. The overall response rate (ORR) to BV was 65% and median duration of response (DOR) was 15.1 months (mo) (Prince et al, Lancet 2017). We hypothesized that reduced-dose BV would improve tolerability without compromising efficacy and therefore facilitate a longer duration of response for pts with MF. Methods: This is a multicenter phase II study evaluating reduced-dose BV in pts with relapsed or refractory MF who are BV-naive. Cohort 1A evaluated BV at 0.9 mg/kg every 3 weeks and cohort 1B evaluated BV at 1.2 mg/kg every 3 weeks. For each dose level, we utilized a Simon two-stage minimax design in which we set the desired ORR at 65% (as reported in ALCANZA) and the null hypothesis at 35%. Accordingly, stage I required 4 responses among the first 9 pts enrolled to expand to a total of 19 pts. In stage II, 11 responses were required to declare the dose promising. Global response was evaluated every 4 cycles using the International Society for Cutaneous Lymphomas consensus criteria (Olsen et al, JCO 2011). PN was evaluated according to the NCI Common Terminology Criteria for Adverse Events v. 4.0.3 and Total Neuropathy Score (TNSc). Additional outcomes include Health Related Quality of Life (HRQoL) measured by the FACT-Lym, FACT-GOG_NTX and Skindex-29 questionnaires completed by pts every four cycles. Results: Among 19 pts enrolled on cohort 1A, median age was 60 years (yrs) (range, 38-85) and 16/19 (84%) were male. Majority had stage I/II disease (n = 16, 84%) and 42% of pts had large cell transformation. Median number of prior therapies was 2 (range 0-9) (Table 1). 8/19 pts (42%) experienced PN, including 3/19 (16%) G2 and 0/19 ≥ G3. ORR was 42% (8/19) (8 PR, 0 CR). Median DOR was 19.6 mo (95% CI, 5.9 - NR) (Figure 1). The primary efficacy endpoint for cohort 1A was not met, leading to enrollment onto cohort 1B. To date, 14 of planned 19 pts enrolled onto cohort 1B. Majority had MF (86%), median age was 62 yrs (range 39-83) and 10/14 (71%) were male. 11/14 (79%) were early stage and 4/14 (29%) had large cell transformation. Median number of prior therapies was 1.5 (range 0-4). 10/14 (71%) pts experienced PN, including 4/10 (40%) G2 and 0/10 ≥ G3. The ORR is 50% (7 PR, 0 CR) and the median DOR has not been reached (95% CI, 5.4 - NR). Across the 2 cohorts, additional BV-related adverse events seen in >10% of pts included infusion-related reactions (G1, n = 3; G2, n = 1), hepatic transaminase elevation (G1, n = 4; G2, n = 1), diarrhea (G1, n = 4; G3, n =1), nausea (G1, n = 4; G2, n =1), fatigue (G1, n = 5; G2, n = 2), and maculopapular rash (G1, n = 4; G2, n = 3; G3, n =2). Conclusion: Treatment of MF with reduced-dose BV of 0.9 mg/kg was associated with lower clinical activity (ORR 42%) than full-dose BV (1.8 mg/kg, ORR 65%). However, while recognizing the limitations of cross-trial comparisons, there were numerically lower rates of PN and a longer median DOR than with full dose BV on the ALCANZA trial. Although unable to reject the null hypothesis for cohort 1A, 0.9 mg/kg dosing allowed for prolonged disease control and diminished toxicity for responding pts. As MF is a chronic, typically incurable condition, prolonged duration of treatment is particularly important. Enrollment onto cohort 1B (1.2 mg/kg) is ongoing; we will present updated results along with pt reported outcomes at the conference.

Valemetostat for Relapsed or Refractory B-Cell Lymphomas: Primary Results from a Phase 1 Trial

Introduction: B-cell non-Hodgkin lymphomas (B-NHLs), including diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL), are among the most common NHLs. Enhancer of zeste homolog (EZH)2 and EZH1 are methyltransferases that catalyze the trimethylation of histone H3 at lysine 27 (H3K27me3); this repressive transcriptional mark is broadly associated with gene silencing. EZH2 is involved in mediating B-cell development. Valemetostat tosylate (valemetostat) is a novel, potent, and selective dual inhibitor of EZH2 and EZH1. The clinical activity of valemetostat in patients (pts) with relapsed or refractory (R/R) NHL was investigated in the phase 1 DS3201-A-J101 (“J101”; NCT02732275) trial. Interim data were reported previously. Here we report primary clinical outcomes for the subgroup of pts in J101 with R/R B-NHLs, including DLBCL and FL. Methods: This phase 1, open-label, multicenter study was conducted in Japan and the United States (US). Eligible pts were aged ≥ 18 years (y; US) or ≥ 20 y (Japan), had confirmed B-NHL or T-cell NHL (T-NHL), and were relapsed from, refractory to, or ineligible for standard therapies. The trial included a dose-escalation portion (Japan only) followed by a dose-expansion phase (Japan & US). Pts with a histological diagnosis of B-NHL were enrolled in the dose-escalation phase and received valemetostat once daily at doses of 150-300 mg/day (d) in continuous 28-d treatment (Tx) cycles. Preliminary efficacy assessment included objective response rate (ORR), complete response (CR) rate, and duration of response (DOR). DOR was estimated for responding pts using Kaplan-Meier methods. Due to the small number of pts with B-NHL, safety was assessed among all enrolled pts, including those with T-NHL in the dose-escalation and dose-expansion cohorts. Results: At the primary trial cutoff (Dec 31, 2022), 19 pts with R/R B-NHLs were registered and had received ≥ 1 dose of study drug, including 7 with DLBCL, 7 with FL, 3 with indolent B-NHL, and 2 with other B-NHLs. Median age was 66 (range 44-88) y. Most (79%) pts had an Eastern Cooperative Oncology Group performance status score of 0. Median number of prior therapies was 2.0 (range 0-6); no pt in this cohort had received prior hematopoietic cell transplantation. Overall, 90 pts with R/R NHLs were enrolled. All pts experienced at least 1 treatment-emergent adverse event (TEAE), including 78 (87%) who had treatment-related TEAEs. The most common TEAEs (any grade) were decreased platelet count (64%), dysgeusia (50%), anemia (43%), decreased neutrophil count (34%), and alopecia (33%). The most common grade ≥ 3 TEAEs were cytopenias, including decreased neutrophil count (24%), platelet count (24%), and lymphocyte count (19%). TEAEs required Tx interruption for 42 (47%) pts, dose reduction for 9 (10%) pts, and Tx discontinuation for 7 (8%) pts. The overall response rate in pts with R/R B-NHL was 47% (9/19; 95% confidence interval [CI], 24.4-71.1). Clinical responses were seen in 3/7 pts with DLBCL and 4/7 pts with FL; 1 pt in each of these groups achieved CR ( Table). Of 19 pts, 9 (47%) achieved reductions of ≥ 50% from baseline in the sum of target lesion areas during valemetostat Tx ( Figure). A gain-of-function EZH2 mutation was identified in 1 pt with FL, and this pt achieved a partial response. Median time to response overall was 3.7 (range 1.9-10.1) months (mo) and estimated median DOR for the 9 responding pts was 18.4 mo (95% CI, 5.3 mo to not reached). Among all pts who received valemetostat 200 mg/d with pharmacokinetic (PK) data available (n = 74), mean [standard deviation; SD] maximum plasma concentration (C max) on cycle 1 day 1 was 2140 [1620] ng/mL, with a median time to C max (T max) of 3.9 (range 0.2-27.8) h and a mean [SD] AUC tau of 17,500 [21,400] ng × h/mL. Conclusions: Valemetostat demonstrated encouraging clinical activity in pts with R/R B-NHLs. The safety profile of valemetostat was acceptable; cytopenias were common but manageable and did not require Tx discontinuation between 150-300 mg/d. Clinical responses were durable, with a median DOR of > 1.5 y. Results for pts in this trial with R/R T-NHLs are presented in another abstract (Jacobsen et al.) at this congress. Ongoing trials of valemetostat in pts with R/R B-NHLs include a phase 2 monotherapy trial in France and Belgium (NCT04842877) and a phase 1/2 trial of valemetostat plus rituximab and lenalidomide (R 2) in the US (NCT05683171).

A Phase I/II Study of Combination of ASTX727, Gilteritinib and Venetoclax in Patients with Relapsed/Refractory FLT3 Mutated Acute Myeloid Leukemia (AML)

Background Activating mutations in FLT3 occur in approximately 30% of patients (pts) with AML. Gilteritinib (GILT), a second-generation type I oral FLT3 inhibitor, has been approved in pts with relapsed/refractory (R/R) FLT3-mutated AML. We conducted a phase I/II study to evaluate the combination of decitabine/cedazuridine (ASTX727), venetoclax (VEN), and GILT in pts with FLT3-mutated R/R AML or intermediate-2/high risk MDS/CMML. Methods This phase I/II study included pts with 1) R/R FLT3-mutated AML or R/R intermediate-2/high risk MDS/CMML or 2) newly diagnosed FLT3-mutated AML unfit for intensive chemotherapy (eligible for phase II only). Here we report the initial data from the R/R cohort. In the phase I portion there was no restriction to the number of prior therapies received; however, in the phase II portion pts who had received ≥3 prior therapies were excluded. Pts with FLT3-ITD and/or TKD mutations were eligible. Pts were required to have a performance status ≤3, total bilirubin ≤2.5 x ULN, ALT/AST ≤3 x ULN, and creatinine clearance ≥30 mL/min. In cycle 1 (C1), pts received decitabine/cedazuridine (35mg/100mg) orally on days 1-5, VEN (ramp-up to 400mg with adjustment for concomitant azole) orally on days 1-28, and GILT orally continuously. The GILT dose ranged from 80mg to 120mg daily during the phase I dose escalation (3+3 design). A bone marrow biopsy was performed on day 14, and if blasts were <5% or the marrow was insufficient/aplastic, the VEN was held. For C2 and beyond, ASTX727 was given for 5 days, VEN was given for 14-21 days and GILT was given continuously. The primary endpoint for the phase I was the MTD; and for the phase II, the overall response (defined as CR, CRh, CRi, or MLFS within 2 cycles of therapy). Results The phase I portion is complete with 12 pts enrolled (11 AML, and 1 high-risk CMML). Nine pts received GILT 80mg and 3 received 120mg. No DLTs at either dose level were observed. However, 80mg of GILT was selected for the phase II portion of this study based on the more favorable safety/efficacy profile and better count recovery observed in a parallel study of azacitidine combined with VEN and GILT in AML. In the combined phase I/II cohort of pts with R/R AML or MDS/CMML, 15 pts have been treated. The median age was 65 years (range 38-83 years). Thirteen pts had a FLT3-ITD mutation (including 2 with a concomitant TKD mutation), and 1 pt had a FLT3-TKDmutation alone. Among pts with a FLT3-ITD, the median allelic ratio was 0.21 (range, 0.09 - 10.6). Among pts with a FLT3-TKD, the median allelic ratio was 0.05 (range, 0.02-0.09). Nine pts had diploid karyotype, 2 had adverse risk karyotype, and 4 had miscellaneous, intermediate-risk cytogenetic findings. The median number of prior therapies was 1 (range 1-9). Among the 15 pts treated, 8 (53%) responded: 1 (6%) with CRh, 3 (20%) with CRi, and 4 (27%) with MLFS. The pt with an isolated FLT3-TKD mutation (along with del7q) did not respond. The pt with high-risk CMML achieved a CRi. Six of 12 pts who received prior HMA + VEN responded (2 CRi and 4 MLFS), and 2 of 3 pts without prior HMA + VEN responded (1 CRh and 1 CRi). The median number of cycles received by pts was 2 (range 1-8). Best response was achieved by the end of C1 in 50% of responders, and by the end of C2 in the other 50% of responders. Of the 8 responders, 1 proceeded to alloSCT (with flow positive MRD at 0.3% but FLT3 negative by PCR), 1 is still receiving treatment on protocol with continued response, 5 relapsed without HSCT (median time to relapse 2 months [range, 0.5-7 months]), and 1 died in MLFS. The transplanted pt remains in MRD-negative remission 5 months after alloSCT and is receiving maintenance GILT off protocol. With a median follow-up of 3.8 months (range, 1-18 months), the median overall survival for the cohort was 6.1 months. There were 3 pts with grade 1-2 toxicities (1 with elevated liver enzymes, 2 with skin rash), 9 pts with grade 3 toxicities (9 with neutropenic fever, 4 of which became septic), no pts with grade 4 toxicities, and 2 patients with grade 5 toxicities (both had neutropenia and died from sepsis while on trial). Conclusion In this poor-risk population of pts with R/R FLT3-mutated AML or MDS/CMML, many of whom received prior HMA + VEN, the combination of ASTX727, VEN, and GILT was active, with an ORR of 53%. The trial continues to enroll to the R/R cohort, and is now open for patients with newly diagnosed FLT3-mutated AML who are unsuitable for intensive chemotherapy.

Preliminary Results from a Phase 1b/2 Open-Label, Multicenter, Dose Optimization Clinical Study of the Safety, Tolerability, and Pharmacokinetic (PK) and Pharmacodynamic (PD) Profiles of Cfi-400945 As a Single Agent or in Combination with Azacitidine in Patients (Pts) with Acute Myeloid Leukemia, Myelodysplastic Syndrome or Chronic Myelomonocytic Leukemia (TWT-202)

Background: CFI-400945 is a potent, selective, orally administered, first-in-class inhibitor of the serine/threonine kinase Polo-like kinase 4 (PLK4), a unique Polo-like kinase family member, that is a conserved upstream regulator of centriole duplication. Dysregulation of PLK4 expression causes loss of centrosome numeral integrity, promotes genomic instability and also potentially enables cancer cells to tolerate genomic instability (Mason et al, Cancer Cell 2014). Its inhibition likely causes mitotic catastrophe. An investigator-initiated study (IIS) demonstrated clinical activity in relapsed/refractory AML with adverse cytogenetics. Dose limiting toxicity was colitis, sepsis and the RP2D 96 mg, three CR's (9 evaluable pts) across 2 dose levels were observed [Data on File, Murphy et al]. We report updated data on a company sponsored study (TWT-202; NCT04730258). Study Design and Methods: TWT-202 is a study of CFI-400945 with 3+3 design in escalation and Simon 2 stage in expansion. For Part 1 (CFI-400945), pts with relapsed and/or refractory AML, MDS, or CMML after >1 prior therapy will be included. Pts with MDS or CMML must have progressed or no response after 4 cycles of hypomethylating agents. For Part 2, (CFI-400945 with azacitidine), pts should have relapsed and/or refractory AML, untreated MDS or CMML. Untreated pts ineligible for intensive therapy may be included. The maximum tolerated dose (MTD) is defined as the dose where dose-limiting toxicities (DLTs) are <1 out of 6 at or below the maximally administered dose. Pharmacokinetics (PK) and pharmacodynamic (PD) markers will be assessed. Results: At 2May2023 cut, 26 pts were enrolled into Part 1. Eighteen (69%) pts had AML, 4 (15%) MDS, 4 (15%) CMML. The median number of prior therapies was 3 (range 1-8), 7 (27%) pts had received a previous stem cell transplant. Twenty (77%) were male, the median age 68 years (range 22, 85). Approximately 80% pts with AML were adverse risk by ELN 2022 criteria. Six pts with AML had TP53 mutations. At 21 days on/7 days off schedule, 5 pts received 32mg, 4 pts 48mg, 3 pts 64mg, 5 pts 80mg, 9 pts 96mg daily. The 28 days on/0 days off schedule was introduced at 96mg, 3 pts enrolled, with 0 DLTs to date. There was 1 DLT at 96mg on the 21/7 schedule (fungemia, gastroparesis, septic shock, enteritis). There have been 23 (89%) SAEs with the following occurring in >3 pts (febrile neutropenia (13 pts), sepsis (5 pts), diarrhea (4 pts), pneumonia (4 pts)). Common treatment emergent adverse events (TEAE) in > 5 pts, all grades, all doses; febrile neutropenia-15 pts (58%), nausea-11 pts (42%), diarrhea, vomiting-both 10pts (39%), hypokalemia- 9 pts (35%), dsypnea, hypophosphatemia-8pts each (31%), anemia-7pts (27%), and abdominal pain, fatigue, hypomagnesemia, pneumonia -6 pts each (23%). 31 % (33 events, 8 pts) ≥grade 3 TEAE's were considered related to CFI-400945 . Three pts (50%) with AML (all with prior venetoclax based therapies) at the 96mg dose level (21/7) from 6 evaluable achieved a response after 1 cycle. One pt (85M) with ELN2022 adverse genetics: complex karyotype, TP53 mutation, achieved CRi, and remains in remission after 3 cycles. One pt (70M) with AML (ELN2022 adverse genetics, complex cytogenetics, TP53 mutation), 2 prior regimens, achieved an MLFS and is pending count recovery. Third pt (51M) had AML normal cytogenetics, ELN 2022 adverse genetics (RUNX1, IDH2, SRSF2), and had relapsed/refractory disease after 5 regimens. The pt achieved an MLFS, however medical complications not related to study drug resulted in dose reduction, therapy hold and subsequent relapse. Pharmacokinetic (PK) evaluations indicated mean terminal-life ranged from 7 - 12 hours. Low accumulation was observed after 21d (AR <2-fold). Exposure in this study is overlapped with that observed in the IIS (Data on File, Murphy et al) study. PD studies evaluating the effect of CFI-400945 on markers of mitosis, ploidy and centriole function are ongoing. Conclusion: CFI-400945 has been generally well tolerated in this difficult to treat patient population, including patients whose disease progressed on or following venetoclax based therapies. Three of 6 evaluable patients with AML achieved a response (MLFS=2, CRi=1) at the 96mg dose. PK characteristics support daily dosing of CFI-400945 and PD studies are ongoing. Dose expansions are planned and a combination with azacitidine will open shortly. Murphy et al, Data on File, PMCC Mason et al Cancer Cell 26, 163-176

Lisocabtagene Maraleucel in Relapsed/Refractory Large B-Cell Lymphoma: Real World Analysis from the Cell Therapy Consortium

Introduction Lisocabtagene maraleucel (liso-cel) is an autologous CD19-directed CAR T cell therapy approved for the treatment of relapsed/refractory (R/R) large B-cell lymphoma (LBCL) based on the TRANSCEND (Abramson et al, Lancet 2020), TRANSFORM (Kamdar et al, Lancet 2022), and PILOT studies (Sehgal et al, Lancet Oncol 2022). Extending clinical trial results for liso-cel to the real-world setting, we performed a multicenter retrospective study to evaluate the safety and efficacy of liso-cel in standard of care practice. Methods Patients (pts) aged ≥18 years with LBCL who received commercial liso-cel infusion between February 2021 (time of FDA approval) and June 2023 at 7 academic US medical centers were identified from the Cell Therapy Consortium registry. Pt and treatment characteristics were summarized descriptively, and the Kaplan Meier method was used for survival outcomes. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were graded per ASTCT consensus criteria. Tumor response was assessed per Lugano criteria locally by the treating clinician. Results As of 6/10/2023, 101 pts underwent liso-cel infusion. Detailed baseline pt characteristics are shown in Table 1. Median age at apheresis was 71 years (range: 30-85) with 35% of pts ≥75 years, 60% were male, 16% had an ECOG PS of ≥2 at apheresis, and 11% had active secondary CNS involvement. By histology, 86% of pts had DLBCL, 7% HGBL, 5% TFL, and 2% PMBCL. Baseline comorbidities included diabetes (18%), stage IV chronic kidney disease (5%), cerebrovascular disease (5%), impaired cardiac ejection fraction (2%), pulmonary dysfunction (2%), impaired hepatic function (2%), and active infection (3%), with 68% having a Charlson Comorbidity Index score of ≥3. Due to comorbidities, 30% of pts would have been ineligible for the TRANSCEND clinical trial. The median number of prior therapies was 3 (range: 1-8) and 16% of pts underwent prior autologous stem cell transplant. Bridging therapy was used in 62% of pts including 41% receiving polatuzumab-based treatment, 24% chemoimmunotherapy, and 21% radiation therapy. Seven (7%) pts received liso-cel on an expanded access trial (NCT04400591) due to a non-conforming product. Median time from apheresis to CAR T-cell infusion was 39 days (IQR: 34-43) and 85% of CAR T-cell infusions occurred inpatient. Any Grade CRS occurred in 49% (3% were Grade ≥3) and any Grade ICANS occurred in 26% (10% were Grade ≥3). Median onset of CRS and ICANS was 4 and 6 days following liso-cel infusion, respectively. Tocilizumab was administered in 31% and 31% of pts received steroids for toxicity management. Nine deaths (9%) unrelated to lymphoma progression occurred at a median of 1.2 months (range: 0.3-4.3) with 2 due to infectious complications, 2 due to other malignancy, 1 due to grade 5 neurologic toxicity, 1 due to concurrent grade 5 neurologic toxicity and grade 5 CRS, 1 due to accidental death, and 2 due to unknown causes. The 6-month incidence of non-relapse mortality was 8% (95% CI, 3.4% - 15%). The overall response rate (ORR) to bridging therapy, as assessed prior to lymphodepletion, was 45% with 17% achieving a complete response (CR). Following liso-cel infusion, response assessment was performed at day 30 and/or day 90 according to treating center practice, or in those determined to have clinical progression. Of the 89 pts evaluable at day 30, the ORR was 81% with 63% achieving a CR. Among 76 pts evaluable at day 90, the ORR was 63% with 58% achieving a CR. With a median follow-up of 10.3 months (range 0.3-22.8), month 6 outcomes were 62.7% (95% CI, 52.8% - 74.3%) for progression-free survival, 71.6% (95% CI, 60.9% - 84.1%) for duration of response, and 77.1% (95% CI, 68.4% - 86.9%) for overall survival ( Figure 1). Conclusions These analyses confirm that efficacy and safety are similar or superior to those of patients enrolled in liso-cel prospective clinical trials for R/R LBCL. Notably, these outcomes were achieved in pts predominately of advanced age and with a significant comorbid burden, recognizing that one-third would have been ineligible for TRANSCEND. These results also likely reflect advancements in patient selection and toxicity management including the real world utilization of novel bridging therapy to temporize and debulk disease. Follow-up is ongoing and updated data will be presented at the meeting.

A Phase 1 Trial Evaluating the Addition of Lenalidomide to Relapsed/Refractory Multiple Myeloma Patients Progressing on Ruxolitinib and Methylprednisolone

Background Ruxolitinib (RUX), an orally administered selective JAK 1/2 inhibitor, has received approval for the treatment of myelofibrosis, polycythemia vera, and graft-versus-host disease. We have previously demonstrated the anti-multiple myeloma (MM) effects of RUX alone and in combination with the immunomodulatory agent lenalidomide (LEN) and glucocorticosteroids both preclinically and clinically. Although we have previously demonstrated that LEN and steroid refractory MM patients respond to the addition of RUX, no studies have evaluated whether LEN can achieve clinical activity among those progressing on the combination of RUX and methylprednisolone. Methods Patients included those with MM showing progressive disease (PD) who had previously received a proteasome inhibitor, LEN, glucocorticosteroids, and at least three prior regimens. Initially, subjects received oral RUX 15 mg twice daily and oral methylprednisolone 40 mg every other day. Those patients who developed PD according to International Myeloma Working Group criteria had LEN 10 mg once daily days 1-21 on a 28-day cycle added to RUX and methylprednisolone which were administered at the same doses they were receiving at the time of PD. Results A total of 29 subjects were enrolled and initially received the combination of RUX and methylprednisolone. Follow up was until June 30, 2023. The median number of prior therapies was 6 (range, 3-12). The overall response rate (ORR) was 31% and the clinical benefit rate (CBR) was 34%. The best responses were 1 very good partial response (VGPR), 8 partial responses (PR), 1 minor response (MR), 12 stable disease (SD), and 7 PD. The median progression-free survival (PFS) was 3.5 mo (range, 0.5-36.2 mo). The median time to response was 3.0 mo (n=10). The median duration of response (DOR) was 12.5 mo (range, 2.8-36.2 mo). Twenty (69%) showed PD and had LEN added to the RUX and methylprednisolone combination: all of these patients were refractory to their last LEN-containing regimen. After the addition of LEN, the ORR was 30% and CBR was 40%. The best responses of patients following the addition of LEN were 2 VGPR, 4 PR, 2 MR, 8 SD, and 4 PD. The majority of patients (71%) who initially achieved a > MR to the two-drug combination responded following the addition of LEN whereas only 23% of patients who did not initially achieve a > MR responded to the addition of the third drug. The median time to response was 2.6 mo (range, 0.7-15 mo). The median DOR was undefined (range, 1.2-10.9 mo). The median PFS was 3.5 mo (range, 0.3-25.9 mo). The median PFS2 (including time from first treatment to end of study or June 30, 2023) was 7.3 mo (range, 0.5-39.9). Treatment was well tolerated with no additional toxicity identified following the addition of LEN. Interestingly, PFS2 was predicted by the patient's baseline serum B-cell maturation level; patients with values above the median (128 ng/mL) had significantly shorter PFS2 than those below it (3.5 mo vs. undefined, p = 0.0337). Conclusion The addition of LEN to heavily, previously treated relapsed/refractory MM patients progressing on RUX and methylprednisolone shows significant clinical activity. This three-drug combination is well tolerated and is able to extend the benefit of RUX-based treatment for these patients. The promising results from this phase 1 clinical trial demonstrate a potential novel, all oral therapeutic approach for treating RRMM patients.