Duration Of Response In Patients Research Articles

Enfortumab Vedotin Following Platinum Chemotherapy and Avelumab Maintenance in Patients with Metastatic Urothelial Carcinoma: A Retrospective Data from the ARON-2EV Study.

Enfortumab vedotin (EV) has been approved for the treatment of patients with locally advanced/metastatic urothelial carcinoma (la/mUC) who previously received platinum-based chemotherapy followed by immune checkpoint inhibitors. However, the pivotal clinical trials did not include patients previously treated with avelumab maintenance therapy. The aim of the present retrospective analysis was to assess the effectiveness of EV following avelumab in patients with mUC enrolled in the ARON-2EV study. The study included 182 patients with mUC treated with EV following avelumab maintenance. The primary objective was to assess clinical outcomes, including progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and duration of response (DoR). Statistical analysis involved Fisher exact test, Kaplan-Meier method, log-rank test, and univariate/multivariate Cox proportional hazard regression models. Median OS and PFS were 12.7 (95% CI 10.2-14.1) and 7.9 (95% CI 6.4-9.9) months, respectively. Complete response (CR) was achieved in 5% and partial response (PR) in 34% of patients, with an ORR of 39%. The DoR in patients who achieved CR/PR was 10.9 months (95% CI 8.1-11.4). The incidence of grade ≥ 3 peripheral neuropathy and skin rash was 9%, followed by 8% of grade ≥ 3 diarrhea and 4% of grade ≥ 3 hyperglycemia. The results of our large international retrospective study confirm the effectiveness of EV and endorse its use in the population of patients with mUC treated with EV following the frontline platinum-based chemotherapy and subsequent maintenance treatment with avelumab.

Point of care CD19 chimeric antigen receptor (CAR) T-cells for relapsed/refractory acute myeloid leukemia (AML) with aberrant CD19 antigen expression

Relapsed/refractory (r/r) acute myeloid leukemia (AML) is associated with poor prognosis. CD19 is a B-cell marker, is aberrantly expressed in AML, mostly with t(8; 21)(q22; q22.1). Here we report the results of a phase 2 study giving point of care produced CD19 CAR T- cells for r/r AML with aberrant expression of CD19 (NCT04257175). Lymphodepletion included fludarabine and cyclophosphamide The response was evaluated by bone marrow (BM) aspiration on day 28. Six patients (5 adults and 1 child) were included. Median number of previous chemotherapy lines was 4 (range, 3–8) and four patients received CAR T-cells 8–18 months post allogeneic hematopoietic stem cell transplantation (allo-HSCT). Cytokine release syndrome (CRS) of any grade occurred in all patients, and 1 patient had grade 3 CRS. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 2 patients at low grades. Tocilizumab was administered to 2 patients and corticosteroids to 3 patients. Four patients achieved a complete remission (CR), while 2/6 progressed (PD). Three patients (2 with CR and 1 with PD) underwent allo-HSCT (it was the second transplant in 2) 2–5 months post CAR T-cells infusion. The median duration of response in patients achieving CR was 8.5 (range; 3–14) months. However, all patients eventually died within 5 (1–18) months.In conclusion, CD19 CAR T- cell treatment for AML is feasible and safe. However, the response is short and should be followed by allo-HSCT. Hopefully, future long term results will be improved by combining the CAR T- cell therapy with the emerging novel effective anti-leukemic compounds.

Efficacy of Sacituzumab Govitecan in Hormone Receptor-Positive/Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: A Comprehensive Systematic Review and Meta-analysis.

Breast cancer is the most diagnosed cancer in women, with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) being the predominant subtype. Sacituzumab govitecan (SG), a novel antibody-drug conjugate, has emerged as a promising treatment for metastatic HR+/HER2- breast cancer. This systematic review and meta-analysis aimed to evaluate its efficacy and safety. Adhering to "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" guidelines, a comprehensive search was conducted in PubMed, Scopus, and Cochrane databases up to December 2023. We included clinical trials and observational studies evaluating SG in patients with HR+/HER2- advanced breast cancer. The primary outcome was progression-free survival (PFS). In contrast, the secondary outcomes included overall survival, objective response rate, clinical benefit rate, duration of response (DOR), and adverse event profiles. Review Manager (Version 5.4) was used for the statistical analysis. Nine studies met the inclusion criteria for systematic review; 2 were suitable for meta-analysis. The pooled analysis showed a hazard ratio of 0.53 (95% CI: 0.34-0.83; P= 0.005; I2 = 86%) for PFSl and a hazard ratio of 0.63 (95% CI: 0.36-1.11; P= 0.11; I2 = 92%) for overall survival. The pooled analysis of the duration of response showed significant results with a standard mean difference = 0.22 (95% CI: 0.03-0.42; P = 0.02; I2 = 61%). SG demonstrates significant benefit in PFS and duration of response in patients of HR+/HER2- advanced breast cancer.

The role of upfront lenalidomide maintenance for primary central nervous system lymphoma following first-line methotrexate treatment: A retrospective study.

Consolidation therapy improves the duration of response among patients with primary central nervous system lymphoma (PCNSL). Lenalidomide maintenance has shown encouraging results in older patients with PCNSL. Herein, we performed a retrospective, single-center analysis to evaluate the effect of lenalidomide maintenance on the duration of response in patients with newly-diagnosed PCNSL. Sixty-nine adult patients with PCNSL who achieved complete remission or partial remission (PR) after induction therapy were enrolled. The median age of patients was 58.0 years. The maintenance group (n = 35) received oral lenalidomide (25 mg/day) for 21 days, every 28 days for 24 months; the observation group did not undergo any further treatment. After a median follow-up of 32.6 months, the maintenance group experienced fewer relapse events. However, the median progression-free survival (PFS) was similar between groups (36.1 vs. 30.6 months; hazard ratio, 0.78; 95% confidence interval, 0.446). Lenalidomide maintenance significantly improved PFS and overall survival (OS) only among patients who experienced PR after induction. The median duration of lenalidomide maintenance was 18 months; lenalidomide was well tolerated and minimally impacted the quality of life. The present study was the first to evaluate lenalidomide maintenance as a frontline treatment among patients with PCNSL, PFS and OS did not improve, although the safety profile was satisfactory.

Abstract CT246: Open-label, single-arm, multicenter, phase 2 trial of garsorasib in KRAS G12C-mutated non-small-cell lung cancer

Abstract Background: Garsorasib (D-1553), a potent KRAS G12C inhibitor, has previously demonstrated promising anti-tumor activity in KRAS G12C-mutated non-small-cell lung cancer (NSCLC) in a phase 1 study. Here we present the efficacy and safety of garsorasib in a pivotal phase 2 study. Methods: In this open-label, multicenter, single-arm phase 2 study, patients received garsorasib 600 mg twice daily in 21-day cycles. Eligible criteria included patients with locally advanced or metastatic NSCLC harboring KRAS G12C mutation, who had disease progression after prior anti-PD-(L)1 therapy and platinum-based chemotherapy or intolerance to the above regimens due to toxicity, and had measurable tumor lesions according to the RECIST, v1.1. The primary end point was objective response rate (ORR) evaluated by independent review committee (IRC) per RECIST v1.1. The secondary end points included duration of response (DOR), disease control rate (DCR), time to response (TTR), progression-free survival (PFS), overall survival (OS), and safety. Results: As of November 17, 2023, 123 patients (108 [87.8%] male, median age 64 [range: 33-80], and 11.4%/88.6% ECOG PS 0/1) were enrolled and treated, with a median follow-up of 7.92 months (range, 0.7, 16.5) and a median duration of treatment of 6.24 months (range, 0.7, 15.9). At data cutoff date, 82 patients (66.7%) discontinued treatment, with disease progression (46 patients [37.4%]) being the most common reason. Among 123 patients, IRC confirmed-ORR was 49.6% (61/123, 95% CI, 40.5 to 58.8) and DCR was 88.6% (109/123, 95% CI, 81.6 to 93.6). The median TTR was 1.38 months (range, 1.12 to 5.55). The median DOR was 12.78 months (95% CI, 6.21 to NE). The median PFS was 7.56 months (95% CI, 5.55 to 9.69), and the median OS was not reached. A total of 117 (95.1%) patients reported treatment-related adverse events (TRAEs) with 61 (49.6%) patients experiencing grade 3 or higher events. The most commonly reported (≥25%) TRAEs (any grade) were increased AST, ALT and γ-GGT, anemia, increased blood bilirubin, and increased blood ALP. No new safety signals were identified, and most of the adverse events were well managed. No TRAE resulted in permanent discontinuation of garsorasib. Conclusions: Garsorasib has shown a high tumor response rate and long response duration in patients with KRAS G12C mutated NSCLC that have progressed after prior anti-PD-(L)1 therapy and platinum-based chemotherapy. Its safety profile was also shown to be well-tolerated and manageable. Garsorasib could be considered as a promising treatment option for KRAS G12C-mutant NSCLC patients with a high unmet medical need. Citation Format: Ziming Li, Xiaomin Dang, Dingzhi Huang, Shi Jin, Weiwei Li, Jianhua Shi, Xicheng Wang, Yiping Zhang, Zhengbo Song, Junping Zhang, Wu Zhuang, Xuewen Liu, Liyan Jiang, Xiangjiao Meng, Mingfang Zhao, Jianying Zhou, Liangming Zhang, Pingli Wang, Hui Luo, Junquan Yang, Shundong Cang, Xiang Wang, Jing Wang, Jiuwei Cui, Yan Yu, Zhihong Zhang, Junguo Lu, Weihua Yang, Gaofeng Li, Jifeng Feng, Dongqing Lv, Lin Wu, Yong Fang, Yan Wang, Yanqiu Zhao, Baoshan Cao, Wei Zhu, Zhixiang Zhuang, Qingshan Li, Mingxi Wang, Huan Zhou, Xiaorong Dong, Sheng Hu, Jian Fang, Yihong Zhang, Wenjia Wang, Ziyong Xiang, Zhe Shi, Ling Zhang, Shun Lu. Open-label, single-arm, multicenter, phase 2 trial of garsorasib in KRAS G12C-mutated non-small-cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT246.

Durable Response to Enfortumab Vedotin Compared to Re-challenging Chemotherapy in Metastatic Urothelial Carcinoma After Checkpoint Inhibitors.

Enfortumab vedotin (EV), an antibody-drug conjugate targeting Nectin-4, has been used for patients with metastatic urothelial carcinoma (mUC) after progressing on checkpoint inhibitors (CPIs). Re-challenging chemotherapy with platinum agents and continuing CPIs beyond progressive disease (PD) have often been chosen following PD on CPIs, and several studies indicate favorable treatment effects of re-challenging chemotherapy. There is little evidence for comparing EV and re-challenging chemotherapy in real-world clinical practice. The aim was to reveal the real-world treatment outcomes of EV, re-challenging chemotherapy, and continuing CPIs beyond PD in mUC patients. A multi-institutional dataset of 350 mUC patients treated with CPIs was utilized. Overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR) were evaluated to compare the treatment arms. One hundred and nine mUC patients were treated with EV with a median follow-up of 6.4months. The ORR and disease control rate (DCR) were 48% and 70%, respectively. The OS from PD on pembrolizumab exhibited significant differences among the three groups, with a median OS of 8, 14, and 29months in continuing pembrolizumab beyond PD, re-challenging chemotherapy, and EV, respectively. When comparing the survival outcomes from the initiation of the treatment, there is neither a difference in OS (p=0.124), PFS (p=0.936), nor ORR (p=0.816) between EV and re-challenging chemotherapy. Notably, the DOR in patients who achieved an objective response was significantly longer in the EV group than the re-challenging chemotherapy group (a median of 11 and 5months, p=0.049). For OS, the difference was not statistically significant (27 and 11months in EV and re-challenging chemotherapy, respectively: p=0.05). A superior effect of EV on patient survival compared to re-challenging chemotherapy and continuing pembrolizumab beyond PD was observed in our real-world analysis, which is attributed to the durable DOR in EV treatment despite the similar ORR to re-challenging chemotherapy.

Phase 3 KEYNOTE-676 cohort A: Bacillus Calmette-Guérin (BCG) with or without pembrolizumab for high-risk (HR) non–muscle-invasive bladder cancer (NMIBC) that persists/recurs after BCG induction.

TPS722 Background: Intravesical instillation of BCG is a standard-of-care treatment for patients with HR NMIBC, but up to 50% of patients later experience disease recurrence or progression to muscle-invasive bladder cancer (MIBC) despite BCG treatment. In the phase 2 KEYNOTE-057 study (NCT02625961), pembrolizumab monotherapy was shown to have antitumor activity in patients with HR BCG–unresponsive NMIBC who had carcinoma in situ (CIS) with or without papillary tumors and in patients with only papillary tumors. In cohort A of the randomized, phase 3 KEYNOTE-676 trial (NCT03711032), pembrolizumab plus BCG versus BCG alone is being evaluated in patients with persistent/recurrent HR NMIBC after first BCG induction. Methods: Key eligibility criteria include adults with histologically confirmed HR NMIBC (T1, high-grade Ta, and/or CIS) that is persistent/recurrent following 1 adequate course of BCG induction therapy, have no concurrent extravesical disease or history of extravesical disease that recurred within 2 years, have an ECOG PS score of 0 to 2, and have undergone cystoscopy/TURBT ≤12 weeks before randomization. Approximately 430 patients will be randomly assigned 1:1 to receive pembrolizumab 200 mg intravenously every 3 weeks plus BCG or BCG alone. BCG (50 mg) will be administered by intravesical instillation as induction therapy once weekly for 6 weeks and then as maintenance therapy once weekly for 3 weeks at weeks 13 and 25, then every 24 weeks (Q24W) thereafter. Treatment will continue for approximately 2 years (pembrolizumab) or 3 years (BCG), or until confirmed persistent/recurrent HR NMIBC or disease progression to MIBC or metastatic bladder cancer, unacceptable toxicity, or withdrawal. Randomization to treatment will be stratified by PD-L1 combined positive score (≥10 or ˂10), histology (CIS or non-CIS), and NMIBC disease history (persistence/recurrence 0 to ≤6 months or recurrence ˃6 to ≤12 months or recurrence ˃12 to ≤24 months). Response will be assessed by local cystoscopy and blinded independent central review of urine cytology and biopsy (as applicable) every 12 weeks for years 1 to 2 and Q24W for years 3 to 5. Computed tomography urography will occur every 72 weeks through year 5, then every 104 weeks thereafter. The primary end point is complete response rate in patients with CIS. Secondary end points are duration of response in patients with CIS, event-free survival, recurrence-free survival, time to cystectomy, overall survival, disease-specific survival, safety and tolerability, and patient-reported outcomes. Enrollment incohort A of KEYNOTE-676 is ongoing in Asia, Australia, Europe, and North America. Clinical trial information: NCT03711032 .

NCMP-04. INITIAL REPORT OF BOSWELLIA SERRATA FOR MANAGEMENT OF CEREBRAL RADIATION NECROSIS AFTER STEREOTACTIC RADIOSURGERY FOR BRAIN METASTASES

Abstract BACKGROUND Radiation necrosis(RN) is a concerning late toxicity after radiation therapy(RT) for brain metastases(BM). Oral corticosteroids are the mainstay of management; however, not optimal given multiple side effects, particularly with the emergence of immunotherapy. Boswellia serrata(BS) is an over-the-counter supplement shown to reduce cerebral edema after brain RT. We evaluated the response rates with BS in a series of BM patients treated with stereotactic radiosurgery(SRS) who developed RN. METHODS We enrolled patients who developed RN after SRS for BM from 2020-2022 and were treated with BS 4.2-4.5g daily. Response was assessed using Response Assessment in Neuro-Oncology(RANO) criteria. Primary endpoint was ≥25% decrease in edema volume on T2-FLAIR MRI from baseline. RESULTS Fifty patients received BS for Grade 1-3 CTCAE v5.0 RN (G1=11, G2=36, and G3=3). Median time to RN was 10 months(m) after SRS and median follow-up was 6m. Best response was a complete response(CR) in 15% patients and partial response(PR) in 40% while 35% had stable disease(SD) and 10% had progression. At 3 , 6 , 9 and 12 months of follow-up respectively, 25%, 60%, 43% and 50% patients had any response(CR or PR). About 56% patients had symptomatic RN, of which 35.7% had improvement in symptoms with BS alone, while 64% required steroid use. Overall, median duration of response in patients with CR, PR or SD was 7.5m(range 2-31m). Salvage treatment for RN was steroids(33), surgery(4), Bevacizumab(5) or hyperbaric oxygen(1). No patient had ≥ CTCAE grade 3 toxicities, while 6% had grade 1-2 gastrointestinal intolerance. Overall, 39 patients remained on BS at last follow-up or death. CONCLUSION We observed > 50% response rates with use of BS in patients with grade 1-3 RN after SRS. Over 1/3rd patients with symptomatic RN were able to avoid long-term steroid use. Further prospective studies comparing Boswellia with placebo are warranted.

Antitumor Activity and Safety of Dostarlimab Monotherapy in Patients With Mismatch Repair Deficient Solid Tumors

Mismatch repair deficiency (dMMR) occurs in various cancers, and these tumors are attractive candidates for anti-programmed cell death 1 therapies, such as dostarlimab, a recently approved immune checkpoint inhibitor. To assess the antitumor activity and safety of dostarlimab in patients with advanced or recurrent dMMR solid tumors. The GARNET trial was a phase 1, open-label, single-group, multicenter study that began enrolling May 8, 2017. Participants had advanced or recurrent dMMR and microsatellite instability-high (MSI-H) or polymerase epsilon (POLE)-altered solid tumors. The data cut for this interim analysis was from November 1, 2021, with median follow-up of 27.7 months. Patients received 500 mg of dostarlimab intravenously every 3 weeks for 4 doses, then 1000 mg every 6 weeks until disease progression, discontinuation, or withdrawal. The primary objective was to evaluate objective response rate and duration of response in patients with dMMR solid tumors by blinded independent central review using Response Evaluation Criteria in Solid Tumors, version 1.1. The efficacy population included 327 patients (median [range] age, 63 [24-85] years; 235 [71.9%] female; 7 [2.1%] Asian, 6 [1.8%] Black, and 206 [63.0%] White patients), with 141 patients (43.1%) with dMMR endometrial cancer, 105 patients (32.1%) with dMMR colorectal cancer, and 81 patients (24.8%) with other dMMR tumor types. All patients had at least 1 previous line of therapy. Objective response rate assessed per blinded independent central review for dMMR solid tumors was 44.0% (95% CI, 38.6% to 49.6%). Median duration of response was not reached (range, ≥1.18 to ≥47.21 months); 72.2% of responders (104 of 144) had a response lasting 12 or more months. Median progression-free survival was 6.9 months (95% CI, 4.2 to 13.6 months); probability of progression-free survival at 24 months was 40.6% (95% CI, 35.0% to 46.1%). Median overall survival was not reached (95% CI, 31.6 months to not reached). The most frequent immune-related adverse events were hypothyroidism (25 [6.9%]), alanine aminotransferase increase (21 [5.8%]), and arthralgia (17 [4.7%]). No new safety concerns were identified. In this nonrandomized controlled trial, dostarlimab was a well-tolerated treatment option with rapid, robust, and durable antitumor activity in patients with diverse dMMR solid tumors. These findings suggest that dostarlimab provides meaningful long-term benefit in a population with high unmet need. ClinicalTrials.gov Identifier: NCT02715284.

Initial Report of Boswellia Serrata for Management of Cerebral Radiation Necrosis after Stereotactic Radiosurgery for Brain Metastases

Radiation necrosis (RN) is a concerning late toxicity after radiation therapy (RT) for brain metastases. Oral corticosteroids are the mainstay of management; however, they are not optimal for long-term use given multiple side effects and drug interactions, particularly with the emergence of immunotherapy for several cancers. Boswellia serrata (BS) is an over-the-counter supplement used for its anti-inflammatory properties and has been recently shown to reduce cerebral edema after brain RT. We evaluated the response rates with BS in a series of patients with brain metastases treated with stereotactic radiosurgery (SRS) who developed RN. We included patients who developed RN after SRS for brain metastases at our institution from 2020-2022 and were treated with BS. Patients were prescribed over the counter BS 4.2-4.5g daily in divided doses. Follow-up MRI imaging was obtained every 2-3 months after starting BS. Response was assessed using Response Assessment in Neuro-Oncology (RANO) criteria. Primary endpoint was ≥25% decrease in edema volume on T2-FLAIR MRI from baseline. Patients were censored if they had tumor progression or repeat RT to necrotic area, or death. Kaplan-Meier curves were used for survival estimates. A total of 50 patients received BS for Grade 1-3 CTCAE v5.0 RN (G1 = 11, G2 = 36, and G3 = 3). Median age was 62.8 years (range 36.9 - 50) and median RT dose was 24 Gy in 3 fractions. Median time to RN after SRS was 10 months(m). Median follow-up after starting BS was 6m and 40 patients had at least 1 follow up MRI available to evaluate response. The best response was complete response (CR) in 15% patients and partial response (PR) in 40% while 35% had stable disease (SD) and 10% had progressive disease. Median time to CR was 9m (6-12m) and PR was 6m (3-12m). Percentage of patients who had any response (CR or PR) at 3, 6, 9 and 12 months was 25%, 60%, 43% and 50%, respectively. 56% patients had symptomatic RN, of which 35.7% had improvement in symptoms with BS alone, while 64% required steroid use. Overall, median duration of response in patients with CR, PR or SD was 7.5m(range 2-31m). Salvage treatment for RN was steroids (33), surgery (4), Bevacizumab (5) or hyperbaric oxygen therapy (1). No patients had any CTCAE grade 3 or higher toxicities. 3 patients (6%) had any side-effects all of whom had Grade 1-2 gastrointestinal intolerance or diarrhea. 2 patients stopped treatment due to enrolment on an immunotherapy clinical trial. Overall, 39 patients remained on BS at last follow-up or death. We observed >50% response rates with use of BS in our cohort of patients with Grade 1-3 RN after SRS. More than 1/3rd patients with symptomatic RN were able to avoid long-term steroid use. BS is an easily available over-the-counter drug that appears to be a safe and promising treatment option for RN, and can potentially decrease steroid dependence in these patients, reducing the risk of several side-effects. Further prospective studies to compare Boswellia with placebo is warranted.

Bruton tyrosine kinase inhibitors in the management of Waldenström macroglobulinemia.

Bruton tyrosine kinase (BTK) inhibitors have taken a central role in the management of patients with Waldenström macroglobulinemia and are the only agents approved by the Food and Drug Administration (FDA) to treat these patients. Although associated with high rates of durable responses, unmet needs with BTK inhibitor therapy include indefinite duration therapy, high cost, scarcity of complete responses, and lower rates and shorter duration of response in patients with CXCR4 mutations. Herein, we review the data supporting the use of covalent BTK inhibitors, selected management issues, clinical trials with covalent BTK inhibitor combination regimens, and up-and-coming non-covalent BTK inhibitors.

Avelumab Plus Talazoparib in Patients With Advanced Solid Tumors

Preclinical data suggest that poly(ADP-ribose) polymerase (PARP) inhibitors have synergistic activity when combined with immune checkpoint inhibitors (ICIs); however, it is unknown which tumor types or molecular subtypes may benefit from this combination. To investigate responses associated with the combination of avelumab and talazoparib in different tumor types and/or molecular subtypes. In this phase 1b and 2 basket nonrandomized controlled trial, patients with advanced solid tumors were enrolled in the following cohorts: non-small cell lung cancer (NSCLC); DNA damage response (DDR)-positive NSCLC; triple-negative breast cancer (TNBC); hormone receptor-positive, human epidermal growth factor receptor 2 (ERBB2)-negative, DDR-positive breast cancer; recurrent, platinum-sensitive ovarian cancer (OC); recurrent, platinum-sensitive, BRCA1/2-altered OC; urothelial cancer; metastatic castration-resistant prostate cancer (mCRPC); DDR-positive mCRPC; and BRCA1/2- or ATM-altered solid tumors. Data were analyzed between June 17, 2021, and August 6, 2021. All patients in phases 1b and 2 received avelumab plus talazoparib. The phase 1b primary end point was dose-limiting toxic effects. The phase 2 primary end point was objective response, measured as objective response rate (ORR). Secondary end points included safety, time to response, duration of response (DOR), progression-free survival, time to prostate-specific antigen progression and PSA response of 50% or greater (for mCRPC), cancer antigen 125 response (for OC), pharmacokinetics, immunogenicity, and biomarkers. A total of 223 patients (mean [SD] age, 63.2 [11.0] years; 117 [52.5%] men) were treated, including 12 patients in phase 1b and 211 patients in phase 2. The recommended phase 2 dose was avelumab 800 mg every 2 weeks plus talazoparib 1 mg once daily. In phase 2, the ORR was 18.2% (95% CI, 5.2%-40.3%) in patients with TNBC; 34.8% (95% CI, 16.4%-57.3%) in patients with HR-positive, ERBB2-negative, and DDR-positive BC; and 63.6% (95% CI, 30.8%-89.1%) in patients with platinum-sensitive, BRCA1/2-altered OC. Responses occurred more frequently in patients with BRCA1/2-altered tumors. Durable responses were observed in patients with TNBC (median [range] DOR, 11.1 [3.4-20.4] months); HR-positive, ERBB2-negative, and DDR-positive BC (median [range] DOR, 15.7 [3.9 to ≥20.6] months); and BRCA1/2-altered OC (median DOR not reached; range, 5.6 to ≥18.4 months). The most common grade 3 or greater treatment-related adverse events were anemia (75 patients [33.6%]), thrombocytopenia (48 patients [21.5%]), and neutropenia (31 patients [13.9%]). This nonrandomized controlled trial found that ORRs for avelumab plus talazoparib were comparable with those with PARP inhibitor or ICI monotherapy. Prolonged DOR in patients with TNBC; HR-positive, ERBB2-negative, and DDR-positive BC; and BRCA1/2-altered OC warrant further investigation in randomized clinical trials. These data highlight the importance of prospective patient selection in future studies of ICI and PARP-inhibitor combinations. ClinicalTrials.gov Identifier: NCT03330405.

PIT565, a First-in-Class Anti-CD19, Anti-CD3, Anti-CD2 Trispecific Antibody for the Treatment of B Cell Malignancies

The robust expression of the CD19 antigen in ALL and NHL has resulted in the development of highly effective therapeutics targeting CD19 by leveraging redirected T cells, which include the bispecific T-cell engager blinatumomab and CD19-directed CAR-T therapies axicabtagene ciloleucel, tisagenlecleucel, and lisocabtagene maraleucel. However, T cell exhaustion contributes to treatment failure following anti-CD19 bispecific T-cell engager and CAR-T therapies. To circumvent this issue, we have developed a first-in-class anti-CD19, anti-CD3, anti-CD2 IgG-like trispecific antibody, PIT565, that simultaneously engages CD19+ on tumor cells, CD3 (TCR signaling component) and CD2 (a costimulatory receptor) on T cells, which leads to redirected T-cell cytotoxicity towards CD19-positive malignant B cells. CD2 signaling has been associated with non-exhausted T cell phenotype. The interaction between CD2 and its ligand, CD58, has been shown to be important for tumor cell killing by CD19 CAR-T cells, while the loss of CD58 expression on lymphoma cells correlates with resistance and relapse in patients treated with CD19 CAR-T therapy. Therefore, CD2 co-stimulation via PIT565 may overcome T cell exhaustion and increase the depth and duration of response in patients compared to CD3 bispecifics. A redirected T cell cytotoxicity (RTCC) in vitro assay, employing co-cultures of CD19+ tumor cells and primary T-cells, demonstrated dose-dependent T-cell proliferation, cytokine production, and tumor cell lysis, which was more potent than the bispecific counterpart. Furthermore, in repeat-challenge RTCC assays, PIT565 mediated more sustained T cell activity in tumor cell killing and proliferation compared to control bispecifics. In addition, PIT565 demonstrated a more robust anti-tumor response than a control bispecific against an established diffuse large B cell lymphoma tumor in the human peripheral blood mononuclear cell adoptive transfer model. In safety and pharmacology studies, PIT565 showed IgG-like pharmacokinetics and an expected pharmacology and tolerability profile similar to CD3 bispecifics in cynomolgus monkey. Taken together, the findings from the preclinical studies suggest that PIT565 may achieve deeper and more durable responses compared to competitor CD3 bispecifics. First-in-human trial of PIT565 (NCT05397496) has been initiated and will be conducted in patients who are diagnosed with relapsed and/or refractory adult NHL after receiving two or more lines of chemotherapy and patients with relapsed and/or refractory B-ALL.

Belantamab Mafodotin in Patients with Relapsed/Refractory Multiple Myeloma, a Real-World Single Center Experience

Introduction Belantamab mafodotin is an antibody drug conjugate targeting B-cell maturation antigen (BCMA) with single agent activity around 32% in the DREAMM2 phase II trial (Lonial et al, Cancer 2021). Side effects, including keratopathy and reduced best corrected visual acuity (BCVA), often necessitate dose reduction and dose delays which may limit efficacy. The aim of this study was to assess response rates, dose modifications, and frequency of ocular adverse events in patients treated with belantamab mafodotin in a real-world setting and in relation to prior treatment with BCMA targeted therapies. Methods All patients treated with at least one dose of commercial belantamab mafodotin at Memorial Sloan Kettering Cancer Center between October 1, 2020 and July 11, 2022 were included in the study. Descriptive statistics were used to assess patient characteristics, response rates, and rate of adverse events. Kaplan Meier curves were used to assess progression free survival (PFS) and overall survival (OS). Results Eighty-two relapsed/refractory multiple myeloma patients were included; 40 (49%) were women median age was 68 years, and 50 patients (61%) had high risk cytogenetics. Twelve patients were treated on the Expanded Access Program with belantamab mafodotin prior to receiving commercial drug. Patients had a median of 6 (range 2-14) prior lines of therapy, all had received an immunomodulatory agent, a proteasome inhibitor, and an anti-CD38 antibody. Sixteen patients (20%) had received one or more BCMA-targeted agents including a bi-specific antibody (N=5), chimeric antigen receptor (CAR) T cell (N=12), and trial therapy with belantamab mafodotin (N=1). Patients received a median of 4 cycles (range 1-31) of belantamab mafodotin. The majority, 96% (N=79), as single agent, while 3 patients were received belantamab mafodotin in combination with other anti-myeloma agents. The overall response rate (ORR) in all patients was 45%; 37/82 patients. Of these, 10 achieved a partial response (PR); 14 patients achieved a very good partial response (VGPR), and 13 patients achieved a complete response (CR) (Table). The median duration of response for patients in the ORR cohort was 11 months. Eighteen patients had stable disease (SD) and 27 patients had progressive disease (PD). The median PFS was 6 months and median OS was not reached. At the end of follow up, 19 patients continued belantamab mafodotin therapy and 28 patients had died. In a separate analysis of patients not included in the Expanded Access Program, the ORR was 43%; 8 had a PR, 13 had a VGPR, and 8 patients had a CR. Of the 16 patients who had prior exposure to BCMA targeted therapy, 5 patients had a PR or better (3 VGPR, 2 CR), 2 patients were in a VGPR/CR at start and continued to respond, 3 patients had SD while 6 patients had PD. The median PFS was similar in patients that were BCMA exposed and those that were BCMA naïve (Figure). Fifty-six patients (68%) had any grade of ocular toxicity per the Keratopathy and Visual Acuity (KVA) scale; 26 patients had grade 1, 15 grade 2, 12 grade 3, and 2 patients had grade 4 keratopathy, respectively. Twenty-six patients had presence of corneal microcysts (information missing in 11 patients). Forty-five patients experienced a decline in BCVA; 22 patients had grade 1, 13 had grade 2, 3 had grade 3, and 1 patient had grade 4 decline in BCVA, respectively (grade missing in 4 patients). The dose of belantamab mafodotin was reduced from 2.5 mg/kg to 1.92 mg/kg in 36 patients while 29 patients had dose delays, the majority due to ocular adverse events but also due to baseline cytopenia, infection, and patient preference. Most patients who had dose modifications due to ocular events were able to continue therapy on a lower dose with maintained response. Nine patients discontinued treatment due to keratopathy, 3 of whom had ongoing grade 1 keratopathy at the end of follow up. Conclusion In this heavily pre-treated multiple myeloma patient population, the ORR was 43-45% which is similar or better than the DREAMM2 phase II trial. The rate of ocular toxicity (68% keratopathy) was comparable to previous reports. Importantly, 5 of 16 patients with exposure to prior BCMA exposure achieved a PR or better while 5 had SD. The PFS was similar in BCMA exposed and BCMA naïve patients. These are encouraging outcomes for belantamab mafodotin in the real-world setting with responses and toxicities comparable to those reported in clinical trials. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Stem Cell Mobilization Characteristics for Transplant Eligible Patients with Newly Diagnosed Multiple Myeloma (NDMM) Treated with Carfilzomib, Lenalidomide, Dexamethasone, and Daratumumab (KRd-Dara)

Introduction: CD38 monoclonal antibody (mAb)-containing quadruplet regimens have been shown to improve depth and duration of response in patients with NDMM eligible for autologous stem cell transplant (ASCT). However, some studies have raised concerns about the detrimental effect of combined lenalidomide and CD38 mAbs on stem cell mobilization. As an exploratory endpoint, we evaluated the effect of KRd-Dara on stem cell mobilization and collection in the Levine Cancer Institute (LCI) KRd-Dara study (NCT04113018) that permits up to 8 cycles of induction with KRd-Dara followed by an MRD-directed treatment algorithm for transplant-eligible and transplant-noneligible patients (Bhutani et al, Blood 2020 Abstr 1388). We provide a table summarizing our results from stage 1, along with two other phase II studies, the MANHATTAN (Landgren et al, JAMA Oncol 2021) and the MASTER (Costa et al, JCO 2021) studies that used variable numbers of KRd-Dara induction cycles prior to stem cell apheresis. Patients and study design: Eligible patients had NDMM and an ECOG performance status score of 0-2. Induction treatment consisted of 28-day cycles of KRd-Dara with intravenous carfilzomib, 20/56 mg/m2 (days 1, 8, and 15); lenalidomide orally, 25 mg (days 1-21); dexamethasone weekly; daratumumab (subcutaneous) per standard approved dosing schedule. One pre-study cycle with non-protocol therapy was allowed. During stage I of the study, stem cell collection for transplant-eligible patients was performed after 8 cycles of induction. All patients were mobilized with granulocyte-colony stimulating factor (G-CSF, 10 µg/kg) daily for 5 days. Preemptive Plerixafor was administered in the evening of Day 4 if the blood CD34+ cell count was <50/µl. Collection was done over 2 days in some patients who failed to collect sufficient CD34+ cells during the first day. A second mobilization attempt after a few weeks of additional wash-out was allowed. Our center-specific minimum required collection target is 3 x 106 CD34+ cells/kg, below which the stem cell dose is considered inadequate to perform a single ASCT. Physicians requested collection for potentially 2 or 3 transplants per patient, with a collection goal of 8 -12 x 106 CD34+ cells/kg. Mobilization failure was defined as the proportion of patients with Day 4 CD34 count <1/µl or collection of <3 x 106 CD34+ cells/kg (considered inadequate for even one ASCT) during the first mobilization attempt. Results: Among the 22 mobilized patients during stage 1 analysis, the median age was 60 years (range, 34 to 72) and 32% were African Americans. Eighteen patients received plerixafor, 3 did not based on futility as their Day 4 blood CD34 count was zero, and only one patient met the threshold of not receiving Plerixafor. The median total CD34+ cells collected were 7.73 x 106/kg (range, 0.00-19.18). Six (27%) patients had mobilization failure after their first attempt. Four of these patients underwent a second attempt after a median of 56 days (range, 36-98 days), with only one patient collecting enough CD34+ cells for one ASCT. Of the 10 patients whose collection goal was 2 transplants (8 million CD34 cells/kg), 9 patients did not meet the goal. Of the 12 patients whose collection goal was 3 transplants (12 million CD34 cells/kg), 8 patients did not meet the goal. Conclusions: The stem cell mobilization failure rate was high in patients collecting after 7 or 8 cycles KRd-Dara. Second remobilization with G-CSF and plerixafor was successful in only 1 of the 4 patients. We have modified stage 2 of the protocol to allow stem cell collection after cycle 3 of KRd-Dara induction. We plan to do combined analyses of LCI, MANHATTAN and MASTER to determine predictive factors associated with poor stem cell mobilization after KRd-Dara induction. Based on our results, we recommend stem cell collection after 3-4 cycles of KRd-Dara regimen. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

214 (PB094) - Covalent FGFR inhibitor futibatinib exhibits sustained antitumor effects compared with ATP-competitive inhibitors by being less prone to ontarget resistance

Background: Futibatinib is a next-generation covalent FGFR1-4 inhibitor. Kinase inhibitors are subject to drug resistance due to acquired mutations of their target kinase, which limits the duration of response in patients. Here we compared the time to emergence of drug resistance caused by FGFR2 kinase mutations between futibatinib and reversible ATP-competitive FGFR inhibitors.

P1131: POST HOC ANALYSIS OF PATIENTS WITH HIGHLY PROLIFERATIVE VARIANTS OF MANTLE CELL LYMPHOMA TREATED WITH ACALABRUTINIB

Background: Blastoid and pleomorphic variants of mantle cell lymphoma (MCL) are considered high risk and have poor prognoses. Patients with these variants rarely achieve durable remission or prolonged clinical outcomes with currently available chemotherapies and targeted therapies. Final results from ACE-LY-004, an open-label, multicenter, single-arm phase 2 study of the Bruton tyrosine kinase (BTK) inhibitor acalabrutinib in adult patients with relapsed/refractory (R/R) MCL confirmed acalabrutinib was highly active in patients with R/R MCL, with a median overall survival of 59.2 months, a median progression-free survival (PFS) of 22.0 months, and a median duration of response (DOR) of 28.6 months after a median 38.1 months of follow-up. In a subgroup analysis, we found that patients with 1 prior line of therapy had unexpectedly shorter DOR than those who had ≥2 prior lines of therapy. Aims: To investigate a possible reason for shorter DOR in patients with R/R MCL treated with acalabrutinib who received only 1 prior line of therapy, we conducted a post hoc analysis on a subgroup of patients with blastoid/pleomorphic disease. Methods: ACE-LY-004 enrolled adult patients with confirmed R/R MCL and an Eastern Cooperative Oncology Group performance status (ECOG PS) of ≤2. Informed consent was obtained. Acalabrutinib 100 mg was administered orally twice daily until occurrence of progressive disease or unacceptable toxicity. Results: A total of 124 patients were enrolled; median age was 68 years and 80% of patients were male. As of December 4, 2020, median follow-up was 38.1 months and median treatment exposure was 17.5 months (range 0.1–65.3). Fifty-nine of the 124 patients (48%) had 1 prior therapy. The remaining 65 patients (52%) had 2 prior therapies (n=37) or ≥3 prior therapies (n=28). Median DOR was longer in patients with ≥2 prior lines of therapy versus those with 1 prior therapy (33.8 and 25.6 months, respectively). Similarly, median PFS was longer in patients who received acalabrutinib in later lines of therapy than in those who received acalabrutinib as second-line therapy (24.8 and 19.2 months, respectively). Among the 59 patients with 1 prior therapy, 16 (27%) had blastoid or pleomorphic disease and 43 (73%) did not, compared with 10 patients (15%) with blastoid/pleomorphic disease and 55 (85%) who did not among the 65 patients with ≥2 prior therapies. Overall response rate (ORR) in those with 1 prior therapy was 88% (n=14; 95% CI 61.7–98.4) in those with blastoid/pleomorphic disease (complete response [CR] in 50%, n=8) versus 81% (n=35; 95% CI 66.6–91.6) in those without blastoid/pleomorphic disease (CR in 47%, n=20). Median DOR for these patients was 20.3 (95% CI 3.5–46.9) and 31.8 (95% CI 14.9–not estimable) months, respectively. Summary/Conclusion: In this post hoc analysis of the ACE-LY-004 study of acalabrutinib in adult patients with confirmed R/R MCL, a shorter DOR was observed among patients who received acalabrutinib after 1 prior therapy compared with those who received acalabrutinib after ≥2 prior therapies, likely explained by a high proportion of patients with blastoid/pleomorphic variants in the group of patients receiving acalabrutinib after 1 prior therapy. While patients with blastoid/pleomorphic variant had comparable ORR, DOR was shorter but still substantial at 20.3 months, indicating that some patients with highly proliferative disease and poorer prognosis also achieve clinical benefit from acalabrutinib.

Baseline cluster of differentiation 22 fluorescent intensity correlates with patient outcome after Inotuzumab Ozogamicin treatment.

Antigen-directed target therapy for B-cell acute lymphoblastic leukemia (B-ALL) is now the standard of care for relapsed/refractory (R/R) disease. A comprehensive determination of the target itself is mandatory to aid physician's choice. We determined baseline Cluster of differentiation 22 (CD22) expression percentage and fluorescent intensity on lymphoblasts of 30 patients with R/R B-ALL treated with anti-CD22 immunoconjugate drug Inotuzumab Ozogamicin (INO) and analyzed the impact of both parameters on patient outcome. Most patients (24/30, 80%) had a high leukemic blast CD22-positivity defined as ≥90%. We did not observe a benefit in terms of complete remission, overall survival (OS) and duration of response (DoR) for patients with CD22≥90% versus CD22<90%. Concerning CD22-FI quartile analysis we appreciated a trend for superior response rates in higher quartiles (Q2 -Q4 ) compared to Q1 and a significant benefit in terms of OS and DoR for patients with higher CD22-FI. INO demonstrates to be effective also in patients with lower CD22 expression, but therapeutical benefits are more evident in patients with higher CD22-FI. The evaluation of both CD22 percentage and CD22-FI of the leukemic blast may help physicians in therapeutic choices for R/R B-ALL patients when multiple treatment options are available, although no CD22 expression threshold can currently be identified below which INO should be considered not effective.

Treatment patterns and outcomes of patients with relapsed or refractory follicular lymphoma receiving three or more lines of systemic therapy (LEO CReWE): a multicentre cohort study

Novel therapies for relapsed or refractory follicular lymphoma are commonly evaluated in single-arm studies without formal comparison with other treatments or historical controls. Consequently, rigorously defined treatment outcomes informing expectations for novel therapeutic strategies in this population are sparse. To inform outcome expectations, we aimed to describe treatment patterns, survival outcomes, and duration of response in patients with relapsed or refractory follicular lymphoma receiving three or more lines of systemic therapy. In this multicentre cohort study, we developed a database of patients with relapsed or refractory follicular lymphoma from eight academic centres in the USA using data collected in the LEO Cohort study (NCT02736357) and the LEO Consortium. For this analysis, eligible patients were aged at least 18 years, had non-transformed grade 1-3a follicular lymphoma, and were receiving systemic therapy in the third line or later after previous therapy with an anti-CD20 antibody and an alkylating agent. Clinical data and patient outcomes were abstracted from medical records by use of a standard protocol. The index therapy for the primary analysis was defined as the first line of systemic therapy after the patient had received at least two previous systemic therapies that included an alkylating agent and an anti-CD20 therapy. The main endpoints of interest were overall response rate, progression-free survival, and overall survival. Outcomes were also evaluated in subsets of clinical interest (index therapy characteristics, patient and disease characteristics, treatment history, and best response assessment). We screened 933 patients with follicular lymphoma, of whom 441 were included and diagnosed between March 6, 2002, and July 20, 2018. Index therapies included immunochemotherapy (n=133), anti-CD20 antibody monotherapy (n=53), lenalidomide with or without anti-CD20 (n=37), and phosphoinositide 3-kinase inhibitors with or without anti-CD20 (n=25). 57 (13%) of 441 patients received haematopoietic stem-cell transplantation and 98 (23%) of 421 patients with complete data received therapy on clinical trials. After a median follow-up of 71 months (IQR 64-79) from index therapy, 5-year overall survival was 75% (95% CI 70-79), median progression-free survival was 17 months (15-19), and the overall response rate was 70% (65-74; 280 of 400 patients evaluable for response). Patients who were refractory to therapy with an alkylating agent had a lower overall response rate (170 [68%] of 251 patients vs 107 [77%] of 139 patients) and a significantly lower 5-year overall survival (72%, 95% CI 66-78 vs 81%, 73-89; hazard ratio 1·60, 95% CI 1·04-2·46) than patients who were not refractory to therapy with an alkylating agent. Patients with relapsed or refractory follicular lymphoma receive heterogeneous treatments in the third-line setting or later. We observed high response rates to contemporary therapies that were of short duration. These data identify unmet needs among patients with follicular lymphoma, especially those who are refractory to alkylating agents, and might provide evidence by which clinical trials evaluating novel treatments could be assessed. Genentech and the National Cancer Institute.

Radioembolization with chemotherapy for liver-dominant colorectal cancer: Analysis of patient subgroups in the EPOCH trial.

115 Background: The EPOCH trial evaluated potential benefit of second-line transarterial radioembolization (TARE) plus chemotherapy compared to chemotherapy alone in patients with liver-dominant metastatic colorectal disease (mCRC). Presented here are additional results from EPOCH of depth and duration of response (DoR), and progression-free survival (PFS) and hepatic progression-free survival (hPFS) subgroup analyses. Methods: EPOCH was a 1:1 randomized, open-label, global, multicenter phase 3 trial of second-line chemotherapy for liver-dominant mCRC comparing outcomes from chemotherapy with or without unilobar or same-day bilobar TARE treatment using glass microspheres. Primary study endpoints were PFS and hPFS. Pre-specified subgroup analyses of PFS and hPFS were performed. PFS, hPFS, DoR for patients with objective response, and depth of response (percent change from baseline to nadir in sum of longest diameters of target lesions) were based on blinded, independent central review using RECIST 1.1. The use of TheraSphere in the trial in the USA was under Investigational Device Exemption from FDA. Results: Both primary endpoints of PFS (HR = 0.69, 95% CI: 0.54, 0.88; 1-sided p=0.0013) and hPFS (HR = 0.59, 95% CI: 0.46, 0.77; 1-sided p&lt;0.0001) were met in the EPOCH study. Median DoR in the 73 responders of the TARE arm was numerically longer, with 7.2 months by Kaplan-Meier analysis; in the 45 responders of the chemotherapy only arm, 6.6 months (HR = 0.79, 95% CI: 0.48, 1.30; 1-sided p = 0.178). Mean depth of response across all patients in the TARE arm with data available (N=196) was -25.6%, compared to -13.0% in the chemotherapy only arm (N=182; mean difference -12.6 percentage points; 95% CI: -18.9, -6.3; 1-sided p = 0.0001). Key subgroups of interest which showed improved PFS and/or hPFS in the TARE arm (ie, 95% CI for the HR entirely below 1) are as follows: Conclusions: These data suggest that liver-dominant mCRC patients in this trial benefitted in second-line treatment from a combination of TARE plus chemotherapy based upon improved PFS and hPFS over the full set of patients and in a number of subgroups. The addition of TARE to chemotherapy improves depth of response compared to chemotherapy alone. Clinical trial information: NCT01483027. [Table: see text]