Key Secondary Objectives Research Articles

Multicenter Open Label Phase 3 Benefit Study of Isatuximab Plus Lenalidomide and Dexamethasone with/without Bortezomib in the Treatment of Newly Diagnosed Non-Frail Transplant Ineligible Multiple Myeloma Elderly Patients. IFM2020-05

Background. The current standard of care for non-transplant eligible (NTE) newly diagnosed multiple myeloma (NDMM) is the combination of anti-CD38 immunotherapy daratumumab to lenalidomide-dexamethasone (DRd) on the basis of the Maia study (Facon et al. NEJM). This regimen has considerably improved the survival objectives for the study and the patients, PFS and OS. Interestingly, the MRD sustained 10-5 negative rate of DRd in MAIA is lower than 15%, alluding to the hypothesis that DRd may be immunogenic more than profoundly debulking in its main MOAs. We and other have hypothesized that adding a proteasome inhibitor (PI) to antiCD38 IT +Rd combination would significantly increase the sustained MRD negativity rate and might improve even further survivals. Two phase 3 studies for registration investigate the role of adding antiCD38 IT to VRd (antiCD38VRd quadruplet-based combination versus VRd), questioning on the added value of antiCD38 to the old standard of care VRd. We believe it is of importance to study the added value of a PI to antiCD38 IT +Rd combination in comparison to antiCD38 IT +Rd (the optimal standard of care today in the NTE NDMM) to demonstrate the impact in debulking of the PI on top of the immunogenic effect with the study of the MRD negative rate. We therefore have conducted the present study of Isa-VRd compared to Isa-Rd (IFM2020-05/Benefit, (NCT04751877). Benefit has fully enrolled as of September 2022, and there has been no safety warnings from the safety committee with the prolonged use of bortezomib for 18 months on a weekly basis in combination to Isa-Rd. Study Design and Methods. 270 NTE NDMM patients, aged [65-79] years old and non-frail, were randomized 1:1 and assigned to either the anti-CD38 mAb isatuximab + Rd (Isa-Rd) or isatuximab + VRd (Isa-VRd lite). Stratification across arms was done according to high-risk MM, age cutoff of 75 years and study centers. Patients receive isatuximab IV 10 mg/kg on days 1, 8, 15, and 22 of cycle 1, days 1 and 15 from cycle 2 to 12 and day 1 from cycle 13 onward, 28-day cycles. Lenalidomide and dexamethasone were given orally as approved. Bortezomib was administered weekly and subcutaneously on days 1, 8, 15 at 1.3 mg/m² from cycle 1 to 12 and on days 1, 15 from cycle 13 to 18, and then stopped. All patients will discontinue dexamethasone after cycle 12. Patients will then continue receiving Isa-Rd until progression in both arms. The primary objective is to evaluate the MRD negativity rate at 10-5 at 18 months in both arms, sustained MRD being key secondary at [12-24] months. The study will be considered positive if the MRD negativity rate at 10-5 at 18 months is 30% in the Isa-VRd arm, and twice as much as Isa-Rd arm within the same time point. Key secondary objectives include the survival analysis (OS, PFS, EFS, TTNT), response rates, duration of response, and safety. Conclusion. The study is estimated to read out March 2024, 18 months after the last patient enrolls.

Maintenance Ruxolitinib Is Associated with Low Rates of Chronic Gvhd Requiring Systemic Treatment in Older Adults with AML/MDS Undergoing Allogeneic HCT: Results of a Phase II Multicenter Trial

Introduction: Despite recent advances in graft-versus-host disease (GVHD) prophylaxis, novel approaches to effective prevention of chronic GVHD remain of utmost importance. This is particularly true for older transplant recipients,for whom high-dose cyclophosphamide or prolonged treatment with corticosteroids is challenging. Ruxolitinib, an oral selective inhibitor of JAK1/2, is FDA-approved for the treatment of refractory acute and chronic GVHD. However, the clinical efficacy of JAK inhibition in preventing severe chronic GVHD is not well characterized. Methods: In this prospective, multicenter phase II trial (NCT03286530), older adult subjects (age 60-80) with AML in CR1 or MDS undergoing RIC allogeneic HCT were enrolled. Transplants could be conducted from HLA-matched related donors or 7/8 or 8/8 HLA-matched unrelated donors. Transplants were required to use busulfan- or melphalan-based reduced intensity conditioning and peripheral blood stem cells. Standard GVHD prophylaxis consisted of tacrolimus and methotrexate (5-10 mg/m 2 on Days +1, +3, and +6 ± +11). Subjects were enrolled prior to transplant. Ruxolitinib therapy could begin between Day +30 and Day +100, after meeting pre-treatment criteria, which included: donor engraftment, ongoing remission confirmed by biopsy, adequate hematopoietic recovery (Hgb ≥8 g/dL, PLT ≥50K/uL), and the absence of progressive acute GVHD. Ruxolitinib was administered at 10 mg BID continuously in 28-day cycles (allowing for dose reductions due to drug interactions or cytopenias), for up to 24 cycles. The primary objective was to evaluate the GRFS at 1-year after HCT. Key secondary objectives included the cumulative incidence of chronic GVHD, acute GVHD, and relapse, as well as overall survival. Results: Seventy-eight subjects were enrolled, and 63 subjects received ruxolitinib on trial. The reasons for not initiating ruxolitinib were acute GVHD (n=4), physician discretion (n=3), disease relapse (n=2), low chimerism (n=2), death (n=2), primary graft failure (n=1), and subject withdrawal (n=1). In the treated subjects, the median age was 68 years (range, 61-79). Fifty-five (87.3%) subjects had AML and 8 (12.7%) had MDS. Transplants were performed from HLA-matched related (n=16, 25.4%) or unrelated (n=47, 74.6%) donors with either Fludarabine/Melphalan (n=34, 54%) or Fludarabine/Busulfan (n=29, 46%). The median start date of ruxolitinib after HCT was day 45 (range, 32-93). The median follow-up of survivors was 19 months (range, 3-64) at last cutoff (2/14/23). At the time of analysis, the median number of cycles on treatment is 14 (range, 1-24). 17 subjects remain on therapy; the reasons for discontinuation include completed treatment (n=21), disease relapse (n=13), adverse events (n=7), and physician discretion (n=5). The most common (severe grade ≥3) adverse events experienced while on ruxolitinib were neutropenia (n=18, 29% of subjects), thrombocytopenia (n=17, 27% of subjects), and anemia (n=16, 25% of subjects). Seven subjects experienced grade ≥3 infectious events; no fungal infections have occurred. In subjects receiving ruxolitinib, the 6-month cumulative incidence of Grade II-IV acute GVHD was 14% (95%CI, 7-24) and Grade III-IV acute GVHD was 4.8% (95%CI, 1.3-12), with three cases of grade II-IV GVHD occurring prior to initiation of ruxolitinib. While the 12-month incidence of all cases of chronic GVHD is 27% (95%CI, 17-39), the 12-month incidence of chronic GVHD requiring systemic therapy is 8.4% (95%CI, 3.1-17). The 18-month cumulative incidence of NRM is 5.6% (95%CI, 1.4-14); with only one death attributed to GVHD and one death due to infection (COVID-19), thus far. The 18-month cumulative incidence of disease relapse is 27% (95%CI, 16-39). The 12-month GRFS (primary endpoint) is 70% (95%CI, 56-80). The 18-month OS, PFS, and CRFS are 78% (95%CI, 64-88), 68% (95%CI, 53-78) and 64% (95%CI, 50-76), respectively ( Figure 1). Conclusion: Prolonged administration of ruxolitinib following allogeneic HCT is associated with low rates of chronic GVHD requiring systemic treatment. The incidence of relapse is comparable to historical rates, suggesting no compromise of GVL effect. Despite the anticipated cytopenias with therapy, most subjects were able to remain on treatment. The incorporation of JAK inhibition into GVHD prevention approaches warrants further investigation.

Efficacy and Safety of Processed Amniotic Fluid (pAF) Drops for the Treatment of Ocular Chronic Graft-Versus-Host Disease

Background: Ocular graft-versus-host disease (GVHD) affects more than 50% of patients with chronic GVHD and can lead to debilitating dry or painful eyes, impaired activities of daily living and poor quality of life. Management is mainly supportive, through control of surface inflammation, lubrication, and control of drainage and evaporation. Amniotic fluid (AF) is a rich source of nutrients, cytokines, and growth factors that has antimicrobial and immunomodulatory activities and may have reparative and regenerative roles in human disease. Investigators at the University of Utah developed protocols to collect AF from full-term pregnant women, process and sterile filter AF to separate cytokines and growth factors from residual cells and debris contained in the no-cellular fraction of AF, and treat patients with different conditions. We report the treatment effects and safety of processed AF (pAF) for the treatment of ocular GVHD. Methods: In this randomized, double-blinded, placebo-controlled phase II trial (NCT# 03298815), patients age ≥ 18 years diagnosed within 5 years after allogeneic hematopoietic transplant with ocular GVHD causing dry eye symptoms requiring lubricant drops >3x/day, punctal plugs, thermally cauterized puncta or special eyewear to relieve pain; or inability to work because of ocular symptoms; or loss of vision due to keratoconjunctivitis sicca were enrolled. Patients with any other chronic GVHD treated with >3 lines of therapy beyond corticosteroids with or without calcineurin inhibitors or sirolimus; or had a difference in dryness between both eyes of >2 points by the International Dry Eye WorkShop (DEWS) 2007 report; or were not willing to discontinue the use of medicated lubricant eye drops prior to randomization were excluded. Randomization was performed within participants, with one eye receiving one drop of pAF and the other eye saline treatment (placebo) twice daily for 30 days. In patients wearing scleral lenses, the eye drops were applied prior to lens insertion in the morning and after removal at night. Patients were allowed to resume their medicated eye drops after the 30-day treatment period. The primary objectives were to determine the day 30 overall response (complete and partial response) and safety of pAF. Response type to treatment is defined in Table 1. Key secondary objectives included longitudinal changes in visual acuity and the corneal surface, and patient-reported outcomes. Results: All fifteen patients' eyes were randomized to either pAF or saline treatment. The median age was 61 years (range, 35-72). At enrollment, six patients wore scleral lenses. The median baseline FACT-G score was 88 (range, 58-104). Baseline eye characteristics by treatment are shown in Table 2. Baseline NIH CC eye scores were similar between pAF and saline-treated eyes. The saline-treated group had more eyes with DEWS score 3 (n=7) compared to the pAF group (n=2). All 15 patients completed treatment. The overall response at day 30 in the pAF and saline-treated groups was 25% and 50%, respectively, p=0.38. All responding eyes had a partial response. No treatment-related serious ocular adverse events were observed. Two minor events occurred in the pAF treated eye group, including a change in eyelid position (n=1) and stinging after study drop application (n=1). There was no significant change in visual acuity and corneal surface staining between treatment groups at 30, 60, and 100 days. There was no significant change in the FACT-G score at 30, 60, and 100 days, and there was no significant difference in patient reported eye pain between pAF vs. saline-treated eyes over time (p=0.21). Conclusion: In this study, the primary endpoint of safety was met as there were few adverse events. One quarter of pAF-treated eyes responded. These findings justify evaluating pAF for ocular GVHD in a larger study. Limitations of this study included restricting patients to pAF application to twice a day and the study design of randomizing eyes within each subject as several patients had mild asymmetric disease between the two eyes. Other challenges included having delayed ocular assessments and/or altered perceptions of quality of life due to the COVID19 pandemic.

Multicenter Open Label Phase 2 Study of Quadruplet-Based Regimen Iskpd (isatuximab plus pomalidomide and dexamethasone with carfilzomib) in Early Relapsed or Refractory Multiple Myeloma - IFM2018-03

Background. RRMM (relapsed or refractory multiple myeloma) is associated to shortened OS (survival) with subsequent relapses and needs optimized treatment approaches. The current treatment paradigm is based on triplet-based association of antiCD38 immunotherapy (antiCD38 IT) with either Imids (Pomalidomide) and dexamethasone or proteasome inhibitors (PI) such as Carfilzomib and dexamethasone. However, quadruplet-based regimens (antiCD38 immunotherapy +Imids +PI +dexamethasone) have transformed the treatment landscape in the upfront setting, improving MRD (minimal residual disease) and survival. We hypothesized that a quadruplet-based regimens (antiCD38 immunotherapy +Imids +PI +dexamethasone) would further improved MRD and survival in early RRMM. We describe a phase II multicentric, open-label study, of isatuximab, pomalidomide and dexamethasone plus carfilzomib (IsKPd/ IFM2018-03, NCT04287855) for patients with early RRMM. Study design and Methods. Approximately 90 patients will receive the association of isatuximab, pomalidomide and dexamethasone with carfilzomib (IsKPd), and the study has fully enrolled 82 patients as of January 2023. Eligible patients are adults aged ≥18 years old with RRMM previously treated with 1 or 2 lines of therapy, including lenalidomide, prior to the study entry. Patients were excluded if they were refractory to any anti-CD38 monoclonal antibody or to carfilzomib, or if they were previously exposed to pomalidomide. Isatuximab will be given by IV route at 10 mg/kg on days 1, 8, 15, and 22 of cycle 1, on days 1 and 15 from cycle 2 to 12 and on day 1 only from cycle 13, 28-day cycles. Carfilzomib will be given by IV route at 20/27 mg/m² on days 1-2, 8-9, 15-16 during cycle 1, at 56mg/m² on days 1, 8, 15 from cycle 2 to 13 and at 56mg/m² on days 1 and 15 after cycle 13. Pomalidomide will be administered by oral route at 3 mg daily on days 1 to 21 in cycle 1 and at 4 mg daily from cycle 12. Dexamethasone will be given by oral route at 40/20 mg daily on days 1, 8, 15 and 22. The primary objective is to evaluate the MRD rate at 10-5 in patients with RRMM treated with IsKPd. Patients will pursue Isa-KPd until progression or unacceptable toxicity. Key secondary objectives include the survival analysis (OS, PFS, EFS, TTNT), response rates and duration of response and evaluation of the safety profile. The study is expected to read out in January 2024 with sustained MRD reported.

RNA Interference Therapy Targeting Apolipoprotein C-III in Hypertriglyceridemia

BackgroundApolipoprotein C-III (APOC3) inhibits triglyceride clearance by reducing lipoprotein lipase–mediated hydrolysis and hepatocyte uptake of triglyceride-rich lipoproteins. ARO-APOC3, a hepatocyte-targeting RNA interference therapeutic, inhibits APOC3 messenger ribonucleic acid expression, lowering triglyceride levels. The objective of this trial was to assess the safety, pharmacodynamic variables, and pharmacokinetic variables of ARO-APOC3 treatment.MethodsHealthy participants and adults with hypertriglyceridemia were randomly assigned to receive escalating single (day 1) or repeat (days 1 and 29) doses, respectively, of subcutaneous injections of ARO-APOC3 10, 25, 50, or 100 mg or placebo; they were followed up until day 113. Additional cohorts of healthy participants and adults with chylomicronemia received repeat doses of open-label ARO-APOC3. The primary objective was to evaluate the safety and side effect profile of ARO-APOC3. Key secondary and exploratory objectives included pharmacokinetic variables and changes in serum APOC3, triglyceride, and cholesterol levels.ResultsEighty-eight participants received ARO-APOC3 and 24 participants received placebo across double-blind and open-label cohorts. Treatment-emergent adverse events (AEs) of transient, mild to moderate liver transaminase changes occurred in 10 participants: 1 patient receiving ARO-APOC3 25 mg, 5 patients receiving ARO-APOC3 50 mg, and 4 participants receiving ARO-APOC3 100 mg (1 healthy participant and 3 patients with hypertriglyceridemia). These events were asymptomatic, and transaminase levels returned to near baseline by the end of the trial. No AEs related to thrombocytopenia or platelet declines were reported. In the hypertriglyceridemia cohorts, the day 113 mean changes from baseline in APOC3 at the 10-, 25-, 50-, and 100-mg doses were −62.0%, −81.7%, −90.1%, and −94.4%, respectively, compared with −1.6% with placebo. This corresponded to median changes in triglyceride levels of −65.6%, −69.9%, −81.2%, and −81.0% compared with −2.8% with placebo.ConclusionsIn this small trial of short duration, ARO-APOC3 was associated with few AEs and reduced serum levels of APOC3 and triglycerides in healthy participants and patients with hypertriglyceridemia. (Funded by Arrowhead Pharmaceuticals, Inc.; ClinicalTrials.gov number, NCT03783377.)

The MAGIC Algorithm Probability Predicts Long-Term Outcomes and Treatment Response to Second-Line Therapy for Acute Gvhd

Introduction: Risk stratification approaches using clinical criteria or biomarkers in acute graft-versus-host disease (GVHD) have traditionally been implemented at diagnosis or initiation systemic treatment with corticosteroids. For patients who require second-line treatment, the significance of biomarkers at salvage therapy and the relationship between biomarker risk and choice of therapy are unknown. Methods: We studied adult patients who received second-line treatment for acute GVHD between January 2016 and December 2021 in the Mount Sinai Acute GVHD Consortium (MAGIC) database, which collects clinical data and longitudinal serum samples from allogeneic HCT recipients using a rigorous PRoBE study design. Exclusion criteria included relapse of underlying malignant disease prior to second-line therapy, missing response data, or missing serum sample. Serum samples collected from 7 days prior to 3 days after initiation of second-line therapy met criteria for biomarker analysis. The MAGIC algorithm probability (MAP) was calculated as a single value based on concentrations of ST2 and REG3α and was stratified at a threshold of 0.290 to define high MAP and low MAP groups. The primary objective evaluated the association between MAP and survival for patients receiving second-line therapy for acute GVHD. The key secondary objective was to investigate the MAP and choice of second-line systemic agent on Day 28 overall response rate (ORR) and survival. Results: In total, 316 adult patients received second-line treatment for acute GVHD; 149 patients (47%) were excluded for disease relapse (n=27), missing response data (n=48), or missing sample (n=74).Of the 167 evaluable patients, most had steroid-refractory acute GVHD (n=146, 87%), rather than steroid-dependent (n=8, 5%) or steroid-sensitive (n=14, 8%) disease. 62 patients received ruxolitinib while 102 received other systemic agents (best available therapy: BAT). Baseline clinical characteristics of the study population according to treatment choice were similar, except for donor type (Rux: MRD 15%, MUD 74%, haplo 11%; BAT: MRD 30%, MUD 67%, haplo 3%; P=0.014) and median days from corticosteroids to second-line treatment (Rux: 18, BAT: 12; P=0.02).In total, 81 patients had high MAPs and 86 patients had low MAPs, with similar distribution in each treatment cohort (P=0.53). For the entire cohort, the median follow-up for survivors was 22 months (range, 1.5-27).The MAP separated patients into 2 groups (high vs low) with significantly different mortality (NRM at 2 years, 76% vs 29%, P<.0001) and survival (OS at 2 years, 12% vs 63%, P<.0001). Patients who received ruxolitinib as second-line therapy had lower mortality (NRM at 2 years, 35% vs 60%, P<.002) and improved survival (OS at 2 years, 51% vs 32%, P<.008), compared to those who received other systemic agents. However, the outcomes of patients with high MAP were poor, regardless of second-line treatment choice ( Figure 1A). The MAP (low vs high), time from corticosteroids to second-line treatment (≥14 days vs < 14 days), GVHD grade at second-line (0-2 vs 3-4), and choice of second-line therapy (Rux vs BAT) were all significant (P<0.05) predictors of lower NRM and higher OS in multivariate analysis. The MAP also separated patients into 2 groups with significantly different D28 ORR (low: 49%, high: 30%, P<.0001). In agreement with prospective trials, ruxolitinib resulted in higher D28 response rates compared to other systemic therapies (ORR 54.9% vs 30.5%, P=0.005), which was observed in both low MAP (ORR, 64.5% vs 38.5%, P=0.017) and high MAP cohorts (ORR, 42.9% vs 22.6%, P=0.06) ( Figure 1B). The MAP (low vs high), GVHD grade at second line (0-2 vs 3-4), and choice of second-line therapy (Rux vs BAT) were significant predictors (P<0.05) of higher D28 ORR in multivariate analysis. Conclusion: The MAP measured at the initiation of second-line systemic treatment for acute GVHD predicts NRM and OS, as well as treatment response. The outcomes of patients with high MAP are poor, regardless of second-line treatment choice, and the higher CR rate in low MAP patients may drive higher survival rates. Incorporation of MAP into clinical trials in this setting warrants investigation. The results also support the current use of ruxolitinib as second-line treatment for acute GVHD, particularly in patients with low MAP.

First Results from a Phase 1, First-in-Human Study of the Bruton's Tyrosine Kinase (BTK) Degrader Bgb-16673 in Patients (Pts) with Relapsed or Refractory (R/R) B-Cell Malignancies (BGB-16673-101)

Introduction: BTK inhibitors (BTKis) are approved for chronic lymphocytic leukemia (CLL), Waldenström macroglobulinemia (WM), mantle cell lymphoma (MCL), and marginal zone lymphoma (MZL). Disease that progresses on BTKis often has BTK mutations that lead to treatment (tx) resistance; novel BTK-targeting agents that overcome BTKi resistance are needed. BGB-16673 is a heterobifunctional small molecule that binds to BTK and E3 ligase, resulting in BTK degradation via ubiquitination. In preclinical models, BGB-16673 degraded wild-type (WT) BTK and known covalent and noncovalent BTKi-resistant mutant proteins, leading to tumor suppression. Methods: Pts with R/R CLL, WM, MCL, MZL, non-germinal center B-cell diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), or Richter transformation (RT) were eligible for this open-label, first-in-human, phase 1 trial (BGB-16673-101; NCT05006716). Pts must have received ≥2 prior therapies (≥1 for RT) and have an ECOG performance status of 0-2 and adequate end-organ function. In the US and Australia, pts must have received a covalent BTKi (cBTKi) if approved for their disease. BGB-16673 was dosed daily by mouth in 28-day cycles. Escalation using a Bayesian optimal interval design with 6 dose levels (50-600 mg once daily) is planned. Primary objectives are to assess safety/tolerability and establish the maximum tolerated dose (MTD) and recommended phase 2 dose. Key secondary objectives are to assess pharmacokinetics, pharmacodynamics (PD), and preliminary antitumor activity. Safety was assessed according to CTCAE v5.0 (all pts) and iwCLL hematologic toxicity criteria (pts with CLL). Dose-limiting toxicities (DLTs) were assessed in the first 4 weeks. Response was assessed per Lugano criteria for all except CLL (iwCLL 2018 criteria) and WM (iwWM-6 criteria). Results: As of May 26, 2023, 26 pts (10 CLL, 4 MCL, 2 MZL, 4 WM, 4 FL, 1 DLBCL, 1 RT) were enrolled at 5 dose levels (50 mg, 4; 100 mg, 9; 200 mg, 9; 350 mg, 3; 500 mg, 1). Median age was 70.5 y (range, 25-83). Median number of prior therapies was 3.5 (range, 2-9), including cBTKis (n=21; 10 CLL, 4 WM, 4 MCL, 1 MZL, 1 RT, 1 DLBCL), BCL2 inhibitors (n=12; 9 CLL, 2 WM, 1 RT), and noncovalent BTKis (ncBTKis; n=4; 2 CLL, 1 WM, 1 FL). In CLL, del17p/ TP53 mutation (n=8) and unmutated IGHV (n=7) were frequent. Median follow-up was 3.5 mo (range, 0.2-13.9). MTD was not reached. Treatment-emergent AEs (TEAEs) were reported by 88.5% of pts (grade [gr] ≥3, 46.2%; serious, 38.5%). The most common TEAEs were contusion (30.8%; no gr ≥3), pyrexia (23.1%; no gr ≥3), neutropenia/neutrophil count decreased (23.1%; gr ≥3, 15.4%), and lipase increased (23.1%; gr ≥3, 3.8%; all transient and asymptomatic). No hypertension or atrial fibrillation was observed. One pt died from sepsis with possible disease progression. No discontinuations due to AEs occurred. Two pts had dose reductions due to TEAEs (gr 3 hematuria with urinary tract infection and recurrent urothelial carcinoma and gr 2 arthralgia). One DLT occurred in 1 pt at 200 mg (gr 3 maculopapular rash on day 27; after 5-day dose hold, assigned dose was recommenced with persistent gr 1 rash). BGB-16673 exposure increased in a dose-dependent manner. At steady state with doses ≥50 mg daily, BGB-16673 exposure exceeded the calculated half maximal degradation concentration for WT and cysteine 481-mutated BTK for the dosing interval. Preliminary PD data showed deep, sustained reductions in BTK protein levels in peripheral blood and tumor tissue, even at the lowest dose. Most CLL pts experienced lymphocytosis during the first 3 cycles of tx. Twenty of 26 pts (77%) remain on therapy (discontinuation: 4 progressive disease, 2 withdrawal). Of 18 response-evaluable pts, 12 (67%) responded (5/6 CLL, 1/3 MCL, 2/2 MZL, 3/4 WM, 1/2 FL, 0/1 DLBCL; 1 CR in MCL, all others had PR; Figure), including pts who received a cBTKi (n=10) and an ncBTKi (n=2). Responses started at the lowest dose level. All responders remain in response, the longest responder remaining on tx for 60 weeks. Conclusions: Preliminary data from this ongoing, first-in-human study of the novel BTK degrader BGB-16673 demonstrate a tolerable safety profile and clinical responses in heavily pretreated pts with B-cell malignancies, including those with BTKi-resistant disease. Substantial reductions in BTK protein levels in peripheral blood and tumor tissue were also observed, demonstrating proof-of-concept of a strong, on-target effect.

Early Safety Results of P-BCMA-ALLO1, a Fully Allogeneic Chimeric Antigen Receptor T-Cell (CAR-T), in Patients with Relapsed / Refractory Multiple Myeloma (RRMM)

P-BCMA-ALLO1 is an allogeneic CAR-T that targets B-cell Maturation Antigen (BCMA) and is currently being investigated for the treatment of RRMM. P-BCMA-ALLO1 cells are manufactured from healthy donor T-cells using non-viral transposon-based integration (piggyBac® DNA Delivery System) that introduces a human anti-BCMA V H-based CAR and an iCas9 safety switch. The piggyBac® DNA delivery system produces a highly enriched T stem cell memory product. The Cas-CLOVER™ Site-Specific Gene Editing System eliminates endogenous T cell receptor (TCR) expression via knockout of the TCR beta chain 1 gene to prevent graft-vs-host disease (GvHD), and the beta-2 microglobulin gene to reduce Major Histocompatibility Complex (MHC) class I expression to eliminate host-vs-graft responses. P-BCMA-ALLO1 demonstrated compelling activity in MM xenografts, providing rationale for this first-in-human phase I study. The primary objective is to assess the safety and maximum tolerated dose (MTD) of P-BCMA-ALLO1 based on dose limiting toxicity (DLT) in RRMM patients with measurable disease who have received a proteasome inhibitor (PI), immunomodulatory agent (IMiD) and anti-CD38 monoclonal antibody therapy. Key secondary objective will assess the anti-myeloma effect of P-BCMA-ALLO1. Exploratory objectives will assess CAR-T related cytokines, serum BCMA levels and cellular kinetics. The trial utilizes a standard 3 + 3 dose escalation design to test seven planned dose levels of intravenous P-BCMA-ALLO1 ranging from 0.0625 × 10 6 to 15 × 10 6 cells/kg (NCT04960579). Multiple lymphodepletion (LD) strategies and cyclic administration of P-BCMA-ALLO1 are being investigated. Repeat P-BCMA-ALLO1 administration is allowed for patients who do not achieve at least a partial response with the first dose after 4 weeks of follow up. We are currently dosing patients in arm S (Cyclophosphamide (Cy) 300 mg/m 2 + Fludarabine (Flu) 30 mg/m 2 X 3 days), arm P1 (Cy 500 mg/m 2 + Flu 30 mg/m 2 X 3 days), arm P2 (Cy 1,000 mg/m 2 + Flu 30 mg/m 2 X 3 days) and arm C (multiple P-BCMA-ALLO1 doses following Cy 300 mg/m 2 + Flu 30 mg/m 2 X 3 days). The median patient age was 73 (33, 85) years, 61% were female, and median time since MM diagnosis was 6.27 (1.48,18.95) years. Eight (35%) patients had high risk disease by cytogenetic criteria. The enrolled patients were heavily pretreated, having received median 7 (2,16) prior lines of therapy, with 30% having undergone prior BCMA targeting therapy. As of 10 Jul 2023, 24 patients received P-BCMA-ALLO1 at 4 dose levels. Twenty-two were treated in arm S, 1 each in arms P1 and P2. One patient received 0.25 X 10 6 cells/kg (cohort -1, arm S), 7 received 0.75 X 10 6 cells/kg (cohort 1, arm S), 12 received 2 X 10 6 cells/kg (cohort 2, 10 in arm S, 1 in arm P1 and 1 in arm P2), and 4 received 6 X 10 6 cells/kg (cohort 3). One of the cohort 2 patients received a second P-BCMA-ALLO1 infusion at the cohort 2 dose level following disease progression. The median time from enrollment to start of LD chemotherapy was 2 (1-8) days and from enrollment to CAR-T infusion was 7 (6-13) days. No patient needed bridging therapy between enrollment and the start of LD. Twenty-two (all in arm S) of the 24 treated patients completed DLT evaluation by data cutoff. None of the patients treated thus far had DLTs. Most common treatment emergent adverse events (TEAEs) were anemia (36%), neutropenia (36%), constipation (36%) and leukopenia (32%). Most common ≥ grade (G) 3 TEAEs were neutropenia (36%), leukopenia (32%) and anemia (23%). Most of the AEs were considered unrelated to P-BCMA-ALLO1. Three (14%) patients developed grade 1 Cytokine Release Syndrome (CRS). One (4%) patient experienced grade 1 Immune Effector Cell Associated Neurotoxicity Syndrome (ICANS), which resolved with one dose of corticosteroids. None of the patients experienced GvHD by the last follow up. P-BCMA-ALLO1 is a non-viral transposon-generated allogeneic “off-the-shelf” CAR-T that is rapidly available for administration and well tolerated in a heavily pretreated RRMM patient population with minimal CRS/ICANS risk. Updated results including safety, preliminary efficacy, and selected biomarkers will be presented at the American Society of Hematology 2023 meeting.

Efficacy and Safety of Venetoclax in Combination with Azacitidine for the Treatment of Patients with Treatment-Naive, Higher-Risk Myelodysplastic Syndromes

Introduction: Azacitidine (Aza) has been shown to prolong survival in patients with treatment-naive, higher-risk myelodysplastic syndrome (HR MDS) compared to lower-intensity, conventional treatment regimens; however, improvement in clinical outcomes are needed. Clinical data on the synergy of Aza with venetoclax (Ven)-a selective, potent BCL-2 inhibitor-in the treatment of myeloid malignancies and the unmet need in HR MDS provide a rationale to evaluate Ven in combination with Aza in treatment-naive HR MDS. Here, we report efficacy and safety data in patients with treatment-naive HR MDS treated with Ven+Aza at the recommended Phase 2 dose (RP2D) in the safety expansion part of the Phase 1b study (NCT02942290). Methods: Adult patients were enrolled with de novo treatment-naive HR MDS defined by the Revised International Prognostic Scoring System (IPSS-R) score of >3 with an Eastern Cooperative Oncology Group performance status of ≤2, and bone marrow (BM) blasts <20% at baseline. Patients received Ven 400 mg orally daily on Days 1-14 and Aza 75 mg/m 2 intravenously or subcutaneously on Days 1-7 or on Days 1-5, 8, and 9 of each 28-day cycle (RP2D). The primary objective was to assess the complete remission (CR) rate. Key secondary objectives included determining marrow CR (mCR), overall response rate (ORR), hematologic improvement (HI), postbaseline red blood cell (RBC) and platelet transfusion independence (TI), overall survival (OS), duration of CR, time to next treatment (TTNT), transformation to acute myeloid leukemia (AML), and time to AML transformation. Responses were assessed by International Working Group 2006 criteria. Prophylactic antibiotics were mandated in Cycle 1 and recommended for Grade ≥3 neutropenia thereafter. Safety was analyzed in patients who received ≥1 dose of study treatment. Results: At thedata cutoff of May 31, 2023, 107 patients had received Ven+Aza at the RP2D. Key baseline characteristics for all treated patients are shown in Table 1A. Median age was 68 years (range, 26-87), 64% of patients had intermediate or poor cytogenetic risk, and >89% had ≥5% BM blasts. Median number of treatment cycles before transplantation was 3.0 (range, 1.0-11.0). At the median follow-up of 31.9 months (95% CI, 30.4-42.5), CR rate was 29.9% (95% CI, 21.4-39.5), with a median CR duration of 16.6 months (95% CI, 10.0-not reached [NR], Table 1B). Median OS was 26 months (95% CI, 18.1-51.5), with an estimated 12-month OS of 71.2% (95% CI, 61.4-78.9)and 24-month OS of 51.3% (95% CI, 41.2-60.5). Median OS for CR was NR. Median TTNT including transplantation was 6.8 months (95% CI, 5.6-8.3). Sixty-two (57.9%) patients received subsequent treatment, including transplantation in 42 (39.3%) patients; the median time to transplantation was 4.8 months (range, 1.4-16.8). Among patients who received transplantation post-study, 17 were transplant ineligible at study entry. Postbaseline TI rate was 61.7% for RBC and 72.0% for platelets. Median maximal duration of TI achieved was 5.4 months (range, 1.8-50.8) and 5.4 months (range, 1.9-56.0) for RBC and platelets, respectively. Postbaseline overall hematologic improvement (HI) was achieved in 51 (49.0%) of 104 evaluable patients, and specific responses included erythroid (40/93; 43.0%), platelet (32/74; 43.2%) and neutrophil (10/57; 17.5%) indices. All patients experienced ≥1 treatment-emergent adverse event (TEAE), with 94.4% of patients reporting grade ≥3 TEAEs. Serious adverse events (SAEs) occurred in 68.2% of patients. Common TEAEs of any grade were constipation (53.3%), nausea (49.5%), neutropenia (48.6%), thrombocytopenia (44.9%), febrile neutropenia (42.1%), diarrhea (41.1%), anemia (39.3%), vomiting (36.4%), and hypokalemia (26.2%). Grade ≥3 TEAEs reported in ≥20% of patients were neutropenia (48.6%), thrombocytopenia (43.0%), febrile neutropenia (42.1%), and anemia (34.6%). Infections were reported in 57% of patients, including SAEs in 40.2% of patients. Of the 59 deaths (55.1%) reported, 23 (21.5%) were due to disease progression and 7 (6.5%) to adverse events. Within 60 days after study start, 7 deaths (6.5%) were reported. Conclusion: Ven 400 mg for 14 days plus Aza combination was well tolerated with favorable responses of CR+PR+mCR in >80% and HI in nearly 50% of patients with treatment-naïve HR MDS. A separate Phase 3 study of this combination is ongoing to confirm survival benefit.

A Phase I Study of CD19-Targeted 19(T2)28z1xx CAR T Cells in Adult Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma

Background: Autologous CD19 CAR T cell therapies have demonstrated favorable clinical responses in relapsed or refractory (R/R) diffuse large B-cell lymphomas (DLBCL), but only a subset of patients (pts) experience durable remissions. We hypothesized that the redundancy of CD28 and CD3ζ signaling in a CAR design incorporating all 3 CD3ζ immunoreceptor tyrosine-based activation motifs (ITAMs) might negatively affect T cell differentiation and promote exhaustion. Therefore, we created a new CD19 CAR construct with calibrated CAR activation potential by mutating 2 of the 3 ITAMs, termed 1XX, and hypothesized that a 1XX CAR would afford durable responses at lower dose and fewer toxicities compared to CARs comprising 3 ITAMs. We previously presented the data from the dose-escalation portion of the phase I clinical trial of 19(T2)28z-1XX CAR T cells in DLBCL (Park J et al. ASH 2022). We have now completed accrual and report the updated results from both dose escalation and expansion portion of the study with a longer follow-up (NCT04464200). Methods: This is a single-center, phase I, dose-escalation and expansion trial of 19(T2)28z1XX CAR T cells in adult pts with R/R DLBCL conducted at Memorial Sloan Kettering Cancer Center. Pts received fludarabine and cyclophosphamide lymphodepleting chemotherapy followed by a single infusion of CAR T cells. There were 4 dose levels in the dose escalation cohort: dose level (DL) 1 (25x10 6), DL2 (50x10 6), DL3 (100x10 6) and DL4 (200x10 6 CAR T cells). The primary objective of the trial was to evaluate safety and tolerability and determine the recommended phase 2 dose. Key secondary objectives include assessment of overall response and complete response rates. Results: 28 pts have been enrolled and treated; 16 pts on the dose escalation and 12 pts on the dose expansion phase of the study. Median age was 62 (range, 48-86). 20 pts (71%) had primary refractory disease, 3 pts (11%) had prior autologous HSCT, and 2 pts (7%) had prior autologous CD19 CAR T therapy. In the dose-escalation phase (n=16), 15 pts experienced grade 1-2 CRS (94%) and no pt experienced ≥grade 3 CRS. Two pts (13%) experienced ICANS: 1 pt with grade 1 and 1 pt with grade 3 (Table 1). Eight pts received tocilizumab and 5 pts received corticosteroid. Complete response (CR) was observed in 11 of 16 pts (69%) and partial remission (PR) in 1 pt (6%) with overall response rate (ORR) of 75%. Responses were seen across all dose levels (Table 1). The lowest dose (DL1: 25x10 6) was selected for dose-expansion based on exposure-response analysis and 12 additional pts were treated at that dose level. In a pooled analysis of 16 pts who received DL1 dose (4 in dose escalation and 12 in dose expansion), 12 pts and 1 pt experienced grade 1-2 (75%) and grade 3 CRS (6%), respectively. Only 1 pt experienced ICANS (6%) at grade 3 (same pt who had grade 3 CRS), which was reversible and transient (Table 1). 11 pts received tocilizumab and 9 pts received corticosteroids. Twelve pts achieved CR (75%) and 2 pts (12%) PR with the best ORR of 87% (Table 1). A lower metabolic tumor volume (MTV) at screening but not at post-bridging was associated with a higher likelihood of achieving CR (p=0.039). With a median follow-up of 345 days (range, 33-1024), 4 pts experienced relapse (1 CR and 3 PR pts) and 16 pts have ongoing CR > 6 months (Figure 1). While CAR T cell persistence analysis is ongoing, 5 pts have CAR T cells detected beyond one year in ongoing CR including a patient treated at DL1 with detectable CAR T cells at 2 years. Conclusions: Treatment with 19(T2)28z1XX CAR T cells was shown to be safe with durable remissions with low rates of severe CRS (4%) and ICANS (7%). The overall CR rate of 71% is encouraging and appears durable with the majority of CR patients in ongoing remission > 6 months at a median follow-up of 345 days and with persisting CAR T cells. With more patients treated at DL1 with a longer follow-up, the study demonstrates a high efficacy of 19(T2)28z1XX CAR T cells at a dose significantly lower (25x10 6) than those of approved CD19 CAR T cells (100-300x10 6) and support that the 1XX single ITAM signaling domain may lead to enhanced efficacy of CD19 CARs and allow infusion of a lower T cell dose with favorable toxicity profiles.

Trial in Progress: An Open-Label, Multi-Center Phase 2 Study to Assess the Safety and Efficacy of Burixafor (GPC-100) and Propranolol with and without G-CSF for the Mobilization of Stem Cells in Patients with Multiple Myeloma Undergoing Autologous Stem Cell Transplant

Background and Significance: Poor stem cell mobilization with failure to produce the target cell dose of ≥2x10 6 CD34 cells/kg required for autologous stem cell transplant (ASCT) occurs in 15-50% of patients with lymphoma or multiple myeloma (MM). Newer therapies may also have a negative impact on mobilization, supporting a need for newer treatment options. Burixafor (GPC-100) is a potent and selective small molecule antagonist of CXCR4. Previous clinical trials with burixafor alone or in combination with G-CSF have demonstrated safe and effective mobilization of stem cells. Preclinical murine studies demonstrated that burixafor in combination with propranolol is a potent mobilizer of white blood cells and mouse stem cells, and mobilization was further augmented with the addition of G-CSF. The goal of the current clinical study is to evaluate the efficacy of burixafor and propranolol in the presence and absence of G-CSF. The triple combination is predicted to be best in class and can target patients at risk for poor mobilization while burixafor plus propranolol will allow for an option when G-CSF is not tolerated, such as in sickle cell disease or patients with autoimmune disease. Study Design and Methods: This study (NCT05561751) is an open-label, randomized, multi-site (U.S. only) Phase 2 trial. Approximately 40 participants will be enrolled across 8-10 sites and randomized in a 1:1 ratio to one of two treatment arms: Burixafor in combination with propranolol or burixafor in combination with propranolol and G-CSF. The study will employ a Bayesian Optimal Phase 2 (BOP2) design for participant enrollment to characterize the safety and clinical activity of burixafor. Participants must be at least 18 years of age, be diagnosed with MM and be eligible for ASCT. Key exclusion criteria include: no more than one year of therapy administered prior to stem cell mobilization, previous stem cell transplant, history of another malignancy, and history of poorly controlled or uncontrolled cardiovascular or pulmonary disease. All participants will self-administer 30 mg propranolol orally twice daily from Days 1 to 8. For participants in the treatment arm receiving G-CSF, they will receive SC injections of 10g/kg/day G-CSF in the afternoon on Days 3 to 7. On days 7 and 8, participants will receive 3.14 mg/kg dose of burixafor via IV and undergo leukapheresis for stem cell collection two hours post drug administration. Participants may undergo additional optional days of the treatment regimen and stem cell collection, per Investigator's discretion to meet institutional standards. The primary objective is to determine the proportion of patients that will achieve at least ≥2 x 10 6 CD34 + cells/kg in 2 leukapheresis sessions following the treatment regimens. Key secondary objectives include: assessment of safety and tolerability of GPC-100 and propranolol with and without G-CSF, evaluation of the pharmacodynamics by determining levels of circulating CD34 + cell counts and levels of the chemokine CXCL12 in peripheral blood, and assessment of mean time to ANC and platelet count recovery after ASCT. Exploratory objectives are also included to discover key biomarkers for patient selection, to evaluate cancer/stem/immune cell profiles, and to evaluate treatment impact on patient quality of life.

A Phase I Clinical Trial of CLL-1 CAR-T Cells for the Treatment of Relapsed/Refractory Acute Myeloid Leukemia in Adults

Background: Relapsed/refractory acute myeloid leukemia (r/r AML) has a poor prognosis, and most patients fail standard chemotherapy and hematopoietic stem cell transplantation or relapse after treatment. We previously reported and evaluated CLL-1-targeted chimeric antigen receptor T-cell therapy in adult r/r AML patients, demonstrating for the first time the efficacy and tolerable safety of CLL-1 CAR-T cell therapy in adult r/r AML patients. On this basis, we expanded the data volume and continued to evaluate the safety and efficacy of CLL-1 CAR-T in AML with dose escalation. Methods: This is a single-center, phase I, dose-escalation trial of CLL-1 CAR-T cell in adult patients with r/r AML (ChiCTR2000041054）admitted to Tianjin First Central Hospital from January 2021 to June 2023. All patients received a lymphodepleting chemotherapy with cyclophosphamide (500mg/m2) and fludarabine (30mg/m2) 3 days before CAR-T cell infusion, followed by 4 incremental doses of CAR-T cells: dose level (DL)1 (0.5×10^6/kg），DL2（1×10^6/kg），DL3（1.5×10^6/kg）and DL4（2×10^6/kg）CAR-T cells. The primary objective of the trial was to evaluate safety and tolerability, and to determine the recommended Phase 2 dose. Key secondary objectives included the assessment of overall response rate, complete response rates as well as progression free survival and overall survival. Results: Thirty patients were enrolled and treated in the dose-escalation phase of the study. The median age of the patients was 38 years (range 18-73), and the median number of prior lines of treatment was 4(2-10), 5(16.67%) patients progressed from MDS to AML, 13(43.33%) patients relapsed after treatment, of which 8(26.67%) patients had previously received HSCT. There were 9, 9, 6 and 6 patients receiving DL1, DL2, DL3 and DL4, respectively. All patients experienced cytokine release syndrome (CRS) (100%): grade 0-2(n=18), grade 3(n=11), grade 4(n=1), and only one patient (3.33%) experienced grade 4 neurotoxicity (NTX), which improved after plasma exchange. In addition, all patients experienced hematological toxicity, with 29 patients (96.67%) developing grade 3/4 granulocytopenia, 28 patients (93.33%) developing grade 3/4 anemia, and 30 patients (100%) developing thrombocytopenia. Patients who received haploidentical bridge transplantation after infusion had normal granulocyte, erythrocyte, and platelet transplantation and did not develop serious infection, suggesting that when severe agranulocytosis occurs after CAR-T infusion, bridge transplantation can reverse this toxicity (Table 1). Efficacy evaluation showed that 73% of patients responded to the infusion, with 12(40%) patients achieving MRD-CR/CRi and 10(33.33%) patients achieving MRD+CR/CRi, for an overall response rate (ORR) of 73.33% (Figure 1). All patients who underwent bridging haploidentical HSCT after CAR-T cell infusion achieved MRD-CR/CRi, and the median time to transplantation was 0.7 months (0.3-1.13). The median OS rate of patients after transplantation was higher than that of patients without transplantation after infusion (P=0.015), as was PFS (p=0.044). The maximum tolerated dose was not determined as no dose-limiting toxic effects were observed. Responses were observed at all dose levels, with a median follow-up of 132 days (range 15-914 days). Patients had a median PFS of 300 days (95% CI, 191.320 to 408.680) and a median OS of 348 days (95% CI, 234.011 to 461.989). The expansion of CLL-1CAR-T cells was tracked by flow cytometry, and the median peak of CAR-T expansion occurred at day 11 (range 2-15) after infusion. When comparing the peak CAR-T expression in CR/CRi and NR patients, the proportion of peak CAR-T cells was significantly higher in CR/CRi patients. Conclusion: CLL-1 is a potential therapeutic target in AML. The proportion of patients who developed severe CRS was low and only 1 patient experienced NTX. Although severe agranulocytosis may occur, patients receiving CLL-1CAR-T therapy may have the opportunity to achieve CR/CRi prior to transplantation, which may reduce the risk of relapse and mortality, and prolong patient survival with encouraging results. Due to the small sample size, no relevant dose-response relationship was observed, and the trial is currently enrolling more cases and will be progressively expanded to Phase II clinical trials.

Sustained Efficacy and Safety with Asciminib (ASC) after Almost 4 Years of Median Follow-up from Ascembl, a Phase 3 Study of ASC Vs Bosutinib (BOS) in Patients (Pts) with Chronic Myeloid Leukemia in Chronic Phase (CML-CP) after ≥2 Prior Tyrosine Kinase Inhibitors (TKIs): An End of Study Treatment (EOS Tx) Update, Including Results from Switch Population

CONCLUSIONS CML requires chronic therapy, emphasizing the need for Txs that are characterized by high, durable efficacy and a low adverse event (AE) burden. ASC, the first BCR::ABL1 inhibitor Specifically Targeting the ABL Myristoyl Pocket (STAMP), demonstrated significantly superior efficacy and better safety/tolerability compared with BOS in pts with CML-CP who received ≥2 prior TKIs in the phase 3 ASCEMBL study. Major molecular response (MMR) rate was 25.5% with ASC vs 13.2% with BOS at wk 24, meeting the primary objective, and 37.6% vs 15.8% at wk 96, meeting the key secondary objective. Despite the longer duration of exposure to ASC, safety/tolerability remained consistently better with ASC vs BOS, with fewer all-grade and grade ≥3 AEs and AEs leading to Tx discontinuation observed. After a median follow-up of 3.7 y, we report EOS Tx results from ASCEMBL (cutoff: March 22, 2023). We also report the first available data from pts who experienced Tx failure on BOS and switched to ASC. Adults (aged ≥18 y) with CML-CP after ≥2 prior TKIs, with intolerance or lack of efficacy per 2013 ELN recommendations were randomized 2:1 to receive either ASC 40 mg twice daily or BOS 500 mg once daily. Pts who met Tx failure criteria per 2013 ELN while on BOS could switch to ASC and were analyzed separately. Pts who discontinued BOS due to intolerance could not switch. EOS will occur 5 y from when the last enrolled pt received first Tx dose. A total of 233 pts were randomized to ASC (n=157) or BOS (n=76). The most common reason for discontinuation was lack of efficacy in 40 (25.5%) pts on ASC and 28 (36.8%) on BOS. At the time of EOS Tx cutoff, Tx with ASC and BOS was ongoing in 77 (49.4%) and 8 (10.5%) pts, respectively; pts deriving benefit from study Tx at EOS TX, per investigator assessment, continued receiving posttrial access. MMR rate at wk 156 continued to be higher with ASC (33.8%) than with BOS (10.5%) (Figure 1). The difference after adjusting for baseline (BL) major cytogenetic response was 23.2%(95% CI, 13.1%-33.2%; 2-sided P<.001). The BCR::ABL1IS ≤1% rate at wk 156 in pts without this level of response at BL also continued to be higher with ASC (43.0%) than with BOS (11.1%). Despite the longer median duration (range) of exposure to ASC (156.0 [0.1-256.3] wk) vs BOS (30.5 [1.0-239.3] wk), safety/tolerability of ASC continued to be better compared with BOS and were consistent with previous analyses. Two new pts had AEs leading to Tx discontinuation since the wk 96 cutoff (1 pt on ASC reported pregnancy; 1 pt on BOS reported diarrhea), and rates remained lower with ASC vs BOS (8.3% vs 27.6%). The most frequent (≥10%) grade ≥3 AEs with ASC vs BOS were thrombocytopenia (22.4% vs 9.2%), neutropenia (18.6% vs 14.5%), diarrhea (0% vs 10.5%), and increased alanine aminotransferase (0.6% vs 14.5%). Most AEs occurred within the first 6 months (Figure 2). Exposure-adjusted incidence rates of arterial occlusive events (AOEs) with ASC decreased since the wk 96 cutoff, from 3.0 to 2.2 per 100 pt-y, and no new AOEs occurred with ASC, indicating that the risk of AOEs did not increase over time. Among pts who discontinued Tx due to lack of efficacy or disease progression, no new mutations occurred since the wk 96 cutoff. Of 28 pts who discontinued BOS for lack of efficacy, 25 switched to ASC. Almost all switch pts (96%) had BL BCR::ABL1IS >10% prior to switch. No switch pts achieved MMR at or by wk 48 post switch. However, at wk 48, 24% achieved BCR::ABL1IS ≤10% and 8% achieved BCR::ABL1IS ≤1%. The safety profile of ASC in switch pts was consistent with that in pts receiving ASC in the randomized period. Most frequent (≥10%) grade ≥3 AEs were neutropenia (32.0%) and thrombocytopenia (24.0%). AEs leading to Tx discontinuation occurred in 8.0% of switch pts. With almost 4 y of follow-up in ASCEMBL, ASC continued to show greater efficacy and better safety/tolerability than BOS in pts with CML-CP after ≥2 prior TKIs. The robust safety profile of ASC was sustained through each analysis in ASCEMBL (wk 24, wk 96, and EOS Tx), confirming that pts receiving ASC can maintain a high level of response and continue Tx without experiencing late-emerging AEs. Results in the switch population support the use of ASC early in the Tx paradigm. ASCEMBL EOS Tx results continue to strongly support ASC as the therapy of choice for pts with suboptimal responses and/or intolerance to ≥2 prior TKIs, allowing more pts to remain on Tx and achieve their Tx goals without needing to switch.

Considerations for Subgroup Analyses in Cluster-Randomized Trials Based on Aggregated Individual-Level Predictors

In research assessing the effect of an intervention or exposure, a key secondary objective often involves assessing differential effects of this intervention or exposure in subgroups of interest; this is often referred to as assessing effect modification or heterogeneity of treatment effects (HTE). Observed HTE can have important implications for policy, including intervention strategies (e.g., will some patients benefit more from intervention than others?) and prioritizing resources (e.g., to reduce observed health disparities). Analysis of HTE is well understood in studies where the independent unit is an individual. In contrast, in studies where the independent unit is a cluster (e.g., a hospital or school) and a cluster-level outcome is used in the analysis, it is less well understood how to proceed if the HTE analysis of interest involves an individual-level characteristic (e.g., self-reported race) that must be aggregated at the cluster level. Through simulations, we show that only individual-level models have power to detect HTE by individual-level variables; if outcomes must be defined at the cluster level, then there is often low power to detect HTE by the corresponding aggregated variables. We illustrate the challenges inherent to this type of analysis in a study assessing the effect of an intervention on increasing COVID-19 booster vaccination rates at long-term care centers.

A Phase 1/2, open label dose-escalation and expansion trial of NKT2152, an orally administered HIF2α inhibitor, to investigate safety, PK, PD and clinical activity in patients with advanced ccRCC

Abstract Background: Inactivation of the VHL gene leading to aberrant HIF2α activity is nearly universal in clear cell renal cell carcinoma (ccRCC). NKT2152 is a novel, potent, selective orally available HIF2α inhibitor optimized for enhanced PK exposure and sustained target inhibition which has demonstrated robust activity in both ccRCC cell line-derived and patient-derived xenograft RCC and other solid tumor models. This is a Phase 1/2 open label, multicenter, first in human study of NKT2152 in adults with advanced clear cell renal cell carcinoma (ccRCC) (NCT05119335). In Phase 1, up to ~60 patients will be enrolled according to a 3 + 3 design with backfill as permitted by the Safety Review Committee. The primary objective of phase 1 is to determine the recommended dose for expansion (RDE) based on the totality of clinical data. Phase 2 will enroll ~50 additional patients with the primary objective of determining investigator-assessed by RECIST v1.1. Key secondary objectives include safety, tolerability, PD effects, progression free survival, duration of response, and disease control rate. Exploratory objectives include evaluation of biomarkers predictive of tumor response. Adults who have advanced ccRCC without available standard therapy), ECOG PS 0-2, with measurable disease per RECIST 1.1 are eligible. Patients who have had prior HIF2a inhibitors, require supplemental oxygen, and with significant cardiac disease are excluded. Tumor assessments by CT or MRI are conducted every 8 weeks until 48 weeks, then every 12 weeks thereafter. Adverse events will be monitored and graded in severity using CTCAE v5.0. The Phase 1 study is currently actively accruing in the United States with Phase 2 dose expansion anticipated to start in Q3, 2023.

Long-term follow-up of allergic bronchopulmonary aspergillosis treated with glucocorticoids: A study of 182 subjects.

The long-term outcomes of allergic bronchopulmonary aspergillosis (ABPA) are poorly characterised. We retrospectively included treatment-naïve subjects of acute stage ABPA-complicating asthma from three randomised trials. All the subjects received oral prednisolone for 4 months and were monitored every 6 weeks for 6 months and then every 6 months. Our primary objective was to estimate the incidence rate and the frequency of subjects experiencing ABPA exacerbation. The key secondary objectives were to evaluate the factors predicting ABPA exacerbation and the changes in serum total IgE seen during treatment. We included 182 subjects. Eighty-one (44.5%) patients experienced 120 exacerbations during 512 patient-years of follow-up. The incidence rate of ABPA exacerbations was 234/1000 patient-years. Most (73/81, 90.1%) subjects experienced ABPA exacerbation within three years of stopping therapy. On multivariate logistic regression analysis, peripheral blood eosinophil count ≥1000 cells/μL (adjusted odds ratio [aOR] 2.43; 95% confidence interval (CI), 1.26-4.67), the extent of bronchiectasis (aOR 1.10; 95% CI, 1.03-1.18), age (aOR 0.97; 95% CI, 0.94-0.99), and female sex (aOR 2.16; 95% CI, 1.10-4.24) independently predicted ABPA exacerbation after adjusting for serum total IgE and high-attenuation mucus. The best cut-off for serum total IgE after 6 weeks for identifying treatment response and ABPA exacerbations was a 20% decline and a 50% increase, respectively. ABPA exacerbations were common within 3 years of stopping treatment. Age, female sex, peripheral blood eosinophilia and the extent of bronchiectasis predicted ABPA exacerbations. The optimal serum total IgE cut-off for defining ABPA response and exacerbations is a 20% decline and a 50% increase, respectively.

Role of C-Reactive Protein and Erythrocyte Sedimentation Rate in the Diagnosis and Monitoring of Treatment Response in Treatment Naïve Subjects with Chronic Pulmonary Aspergillosis.

The role of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) for diagnosing chronic pulmonary aspergillosis (CPA) remains unknown. Herein, we investigate the diagnostic performance of serum ESR and CRP in CPA. We retrospectively analyzed the data of treatment-naïve subjects with CPA and diseased controls (post-tuberculosis lung disease on CT thorax). We treated CPA subjects with six months of oral itraconazole. Our primary objective was to evaluate the sensitivity and specificity of ESR and CRP in diagnosing CPA. The key secondary objective was to study the change in the inflammatory markers with treatment. We included 434 subjects and 20 diseased controls. The sensitivity and specificity of ESR (n = 434) and CRP (at cut-off value of 10mg/L, n = 308) in diagnosing CPA were 42.9% and 65%, and 52.3% and 65%, respectively. Both ESR and CRP had erratic trend following treatment. ESR and CRP declined or remained stable in approximately 60% of subjects but increased in approximately 40% of the subjects despite treatment. Serum CRP and ESR have limited utility in diagnosing and following subjects with CPA.

Soluble Nogo-Receptor-Fc decoy (AXER-204) in patients with chronic cervical spinal cord injury in the USA: a first-in-human and randomised clinical trial

Spinal cord injury (SCI) causes neural disconnection and persistent neurological deficits, so axon sprouting and plasticity might promote recovery. Soluble Nogo-Receptor-Fc decoy (AXER-204) blocks inhibitors of axon growth and promotes recovery of motor function after SCI in animals. This first-in-human and randomised trial sought to determine primarily the safety and pharmacokinetics of AXER-204 in individuals with chronic SCI, and secondarily its effect on recovery. We conducted a two-part study in adults (aged 18-65 years) with chronic (>1 year) cervical traumatic SCI at six rehabilitation centres in the USA. In part 1, AXER-204 was delivered open label as single intrathecal doses of 3 mg, 30 mg, 90 mg, or 200 mg, with primary outcomes of safety and pharmacokinetics. Part 2 was a randomised, parallel, double-blind comparison of six intrathecal doses of 200 mg AXER-204 over 104 days versus placebo. Participants were randomly allocated (1:1) by investigators using a central electronic system, stratified in blocks of four by American Spinal Injury Association Impairment Scale grade and receipt of AXER-204 in part 1. All investigators and patients were masked to treatment allocation until at least day 169. The part 2 primary objectives were safety and pharmacokinetics, with a key secondary objective to assess change in International Standards for Neurological Classification of SCI (ISNCSCI) Upper Extremity Motor Score (UEMS) at day 169 for all enrolled participants. This trial is registered with ClinicalTrials.gov, NCT03989440, and is completed. We treated 24 participants in part 1 (six per dose; 18 men, six women), and 27 participants in part 2 (13 placebo, 14 AXER-204; 23 men, four women), between June 20, 2019, and June 21, 2022. There were no deaths and no discontinuations from the study due to an adverse event in part 1 and 2. In part 2, treatment-related adverse events were of similar incidence in AXER-204 and placebo groups (ten [71%] vs nine [69%]). Headache was the most common treatment-related adverse event (five [21%] in part 1, 11 [41%] in part 2). In part 1, AXER-204 reached mean maximal CSF concentration 1 day after dosing with 200 mg of 412 000 ng/mL (SD 129 000), exceeding those concentrations that were efficacious in animal studies. In part 2, mean changes from baseline to day 169 in ISNCSCI UEMS were 1·5 (SD 3·3) for AXER-204 and 0·9 (2·3) for placebo (mean difference 0·54, 95% CI -1·48 to 2·55; p=0·59). This study delivers the first, to our knowledge, clinical trial of a rationally designed pharmacological treatment intended to promote neural repair in chronic SCI. AXER-204 appeared safe and reached target CSF concentrations; exploratory biomarker results were consistent with target engagement and synaptic stabilisation. Post-hoc subgroup analyses suggest that future trials could investigate efficacy in patients with moderately severe SCI without prior AXER-204 exposure. Wings for Life Foundation, National Institute of Neurological Disorders and Stroke, National Center for Advancing Translational Sciences, National Institute on Drug Abuse, and ReNetX Bio.

RARE-02. OBSERVATIONAL REGISTRY STUDY OF TREATMENT PRACTICES AND LONG-TERM OUTCOMES OF CHILDREN WITH NEUROFIBROMATOSIS TYPE 1 (NF1) AND PLEXIFORM NEUROFIBROMAS (PN) INITIATING SELUMETINIB IN REAL-WORLD PRACTICE IN THE UNITED STATES (US): STUDY DESIGN AND METHODOLOGY

Abstract Selumetinib (ARRY-142886, AZD6244) is an oral, allosteric MEK1/2 inhibitor approved in the US for children aged ≥2 years with NF1 and symptomatic, inoperable PN, based on results from the pivotal SPRINT study. Aims of the US Selumetinib Registry study [NCT05683678] include understanding treatment practices and assessing short- and long-term safety and effectiveness outcomes of selumetinib treatment in children with NF1-PN in real-world US practice. Clinical and non-clinical factors affecting outcomes will also be explored. This observational registry study of pediatric patients with NF1-PN will be conducted in up to 22 US centers. Eligible patients will be 2–18 years old at the time of selumetinib initiation (on/after April 10, 2020), and not currently participating in a clinical trial. Patients will be divided into three cohorts: Cohort 1 – treatment discontinued before enrollment, Cohort 2 – treatment initiated before enrollment and currently on treatment, Cohort 3 – treatment initiation intended within 3 months of enrollment. Patients will be followed for ≥36 and up to 60 months. Primary objectives are to describe patient demographics and disease characteristics (including diagnosis criteria and related manifestations, diagnostic tests and results, and PN-related morbidities), selumetinib treatment course, short- and long-term effectiveness and safety, and disease course and treatment following discontinuation. Key secondary objectives include measures of quality of life, pain and physical functioning before, during, and after selumetinib. Target enrollment is 200 patients with a 24-month enrollment period and will begin in 2023. The US Registry study will facilitate understanding of treatment practices and assess short and long-term outcomes of selumetinib for NF1-PN in a real-world setting.

The final analysis of a phase I/II study of nivolumab, ipilimumab combined with nintedanib in advanced non-small cell lung cancer.

9102 Background: Nintedanib (NT) is an oral triple kinase inhibitor that is active against NSCLC and inhibits the activity of the immunosuppressive cancer associated fibroblasts in the tumor microenvironment (TME). Targeting the TME with NT may represent an important synergistic approach in improving immunotherapy (IO) outcomes for NSCLC. We initiated a phase Ib/II trial to evaluate the combination of NT, nivolumab (N) and ipilimumab (I) in advanced (a)NSCLC. Based on the phase IB (dose escalation) results, the combination of N (3mg/kg/2w), I (1mg/kg/6w) and NT (150mg once daily) was declared as the recommended phase 2 dose (RP2D). Here we present the final analysis of the regimen in treatment naïve (TN), and IO pretreated (IP) aNSCLC. Methods: This is a single institution, non- randomized, parallel assignment phase I/II clinical trial of aNSCLC pts. Eligible pts were TN (Arm A) or with disease progression following IO (Arm B) with planned sample size of 40/arm. Enrollment into phase II was by the Bayesian two-stage design method with the primary objective of determining the overall response rate (ORR) in the intent to treat population. Key secondary objectives were overall survival (OS) and progression-free survival (PFS). Descriptive statistics were used to summarize demographic and safety data. The Kaplan- Meier method with log-rank test (5% level of significance, 95% CI and 2-sided test) was used for survival analysis. Results: 22 and 29 pts received the N+I+NT at the RP2D in Arm A and B, respectively. The median age was 67 [42;92] with 53% (27/51) females, 84% (42/51) Caucasian, ECOG 1 in 88% (45/51), and a current/prior history of tobacco use in 88% (45/51) pts. Adenocarcinoma histology was common (64%, 33/51) with PD-L1 ≥1% in 52% (22/42) pts. As of Oct 24, 2022, 18 and 26 pts were evaluable for response in Arm A and B, respectively. Clinical efficacy was observed in the TN and IP cohorts (Table). The most common treatment-related adverse events (TRAEs) were similar in both cohorts. TRAE of any grade in Arm A were nausea (8, 36%), diarrhea (8, 36%), fatigue (7, 32%), and in Arm B were nausea (10, 34%), fatigue (9, 31%), anorexia (8,27%). Conclusions: The combination of nivolumab, ipilimumab and nintedanib had a manageable toxicity profile and demonstrated promising antitumor activity in both TN and IP aNSCLC patients. Clinical trial information: NCT03377023 . [Table: see text]