Citations

Abstract INTRODUCTION: Belantamab mafodotin (BLMF) is a first-in-class, antibody-drug conjugate targeting B-cell maturation antigen on myeloma cells. BLMF was approved for use in patients (pts) with advanced multiple myeloma (MM). Due to the risk of ocular toxicity, it is made available through a restricted program under a Risk Evaluation and Mitigation Strategy. It is speculated that monomethyl auristatin F (MMAF), the cytotoxic payload of BLMF may be internalised by the corneal epithelium via an off-target mechanism, leading to epithelial changes. In the pivotal DREAMM-2 trial, only 1% of pts permanently discontinued treatment due to keratopathy. Data regarding BLMF-induced ocular toxicity following its commercial availability since August 2020, are sparse, and in this context, we evaluated our clinical experience with BLMF to determine the impact of its ocular toxicity on outcomes when utilized outside of stringent clinical trial settings. METHODS: We reviewed records of pts with advanced MM who were evaluated at Mayo Clinic between 09/01/2020-07/01/2021 and initiated on BLMF monotherapy following a baseline ophthalmic examination that was also performed prior to each dose, and as needed for worsening ocular symptoms. Data pertaining to ocular symptoms, best corrected visual acuity (BCVA) and corneal examinations were collected and analyzed with respect to patient outcomes. Adverse events were graded using the National Cancer Institute Common Toxicity Criteria for Adverse Events v5.0. RESULTS: Thirty-four pts, with median age of 67 (range:49-90) years who received BLMF at the approved 2.5 mg/kg dose as their first infusion and completed at least one cycle were included. All patients were instructed to use preservative-free lubricant eye drops at least 4 times a day, starting with the initial infusion and continuing until the end of therapy, and avoid contact lenses. The median number of prior lines of therapy was 8 (range: 2-15). The median time to BLMF initiation from the diagnosis of MM was 7.5 (range: 1.3-19.7) years. The median follow-up from initiation of BLMF was 7 [95% confidence interval (CI): 5.7-8.6] months, and the median number of BLMF doses administered was 2 (range: 1-6). Twenty-seven (79%) pts experienced ocular toxicity, comprising keratopathy [n=25 (74%)] and/or decreased visual acuity [n=21 (62%)]. Table 1 outlines the keratopathy-related details. Thirteen pts (38%) developed symptomatic xerophthalmia. A clinically significant decrease in BCVA of equal or worse than 20/40 in the better-seeing eye was observed in 12 (35%) pts at a median of 1.7 (95%CI: 1.4-2.2) months of commencing BLMF. In 7 (58%) pts, it improved to better than 20/40 within a median of 3 (range: 0.7-4) months from the time of documentation of impaired BCVA following withholding treatment (n=5), with or without subsequent dose reduction or its permanent discontinuation (n=2). Treatment was permanently discontinued in 5 (15%) pts after a median of 3 doses due to grade ≥2 keratopathy. It was withheld in 9 (26%) due to grade ≥2 keratopathy. Four (12%) pts required dose reduction due to keratopathy (Table 1). Of 14 pts in whom BLMF was held or permanently discontinued due to keratopathy, 10 (77%) had disease progression within a median of 1 month (range 0.4-2.5) following BLMF interruption. Among 11 pts (32%) responded to BLMF, 45% developed grade 2 or higher keratopathy after the first dose compared to 13% of pts who were refractory to BLMF (n=23). The median duration of response was 4 (95%CI: 0.7-NR) months. Among responders, 2 pts (18%) had to permanently discontinue BLMF due to keratopathy, with subsequent progression from partial remission at 1.4 and 4.6 months following its discontinuation. Additionally, 73% of responders required dose withholding due to keratopathy and of those, 50% had evidence of disease progression within a median of 1.2 month (range: 0.7-1.7) following BLMF interruption. DISCUSSION & CONCLUSIONS : Despite efficacy in pts with advanced MM, in routine practice, ocular toxicity of BLMF is a major challenge and a deterrent to its continuous use. While frequent ocular toxicity-related interruptions were observed at expected rates, permanent treatment discontinuation due to keratopathy was observed in a higher proportion of pts than that encountered in the DREAMM-2 trial. Larger prospective studies are warranted to accurately discern the effects of ocular toxicities on outcomes of pts treated with BLMF. Figure 1 Figure 1. Disclosures Patel: Emmecell: Consultancy; GlaxoSmithKline: Consultancy; Senju Pharmaceuticals: Consultancy; Santen, Inc.: Consultancy. Kumar: Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Roche-Genentech: Consultancy, Research Funding; Carsgen: Research Funding; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Research Funding; Astra-Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Amgen: Consultancy, Research Funding; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Tenebio: Research Funding; Beigene: Consultancy; Oncopeptides: Consultancy; Antengene: Consultancy, Honoraria; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bluebird Bio: Consultancy; Adaptive: Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Research Funding. Ailawadhi: AbbVie: Consultancy; Xencor: Research Funding; Medimmune: Research Funding; Genentech: Consultancy; Ascentage: Research Funding; Takeda: Consultancy; Sanofi: Consultancy; Amgen: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Cellectar: Research Funding; BMS: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; GSK: Consultancy, Research Funding; Karyopharm: Consultancy; Beigene: Consultancy. Bergsagel: Celgene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Novartis: Consultancy, Honoraria, Patents & Royalties: human CRBN mouse; Genetech: Consultancy, Honoraria; Oncopeptides: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria. Gertz: Ionis Pharmaceuticals: Other: Advisory Board; Akcea Therapeutics, Alnylam Pharmaceuticals Inc, Prothena: Consultancy; Akcea Therapeutics, Ambry Genetics, Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Karyopharm Therapeutics, Pfizer Inc (to Institution), Sanofi Genzyme: Honoraria; Aurora Biopharma: Other: Stock option; AbbVie Inc, Celgene Corporation: Other: Data Safetly & Monitoring. Kapoor: Karyopharm: Consultancy; AbbVie: Research Funding; Sanofi: Research Funding; Takeda: Research Funding; Cellectar: Consultancy; BeiGene: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy; Amgen: Research Funding; Ichnos Sciences: Research Funding; Regeneron Pharmaceuticals: Research Funding; Glaxo SmithKline: Research Funding; Karyopharm: Research Funding.

Abstract Introduction: Mantle cell lymphoma (MCL), Waldenström macroglobulinemia (WM), marginal zone lymphoma (MZL) and chronic lymphocytic leukemia (CLL) are subtypes of non-Hodgkin's lymphoma. Collectively, these subtypes constitute a large proportion of all B-cell malignancies; however, they are typically associated with survival spanning several years with multiple interspersed treatment periods due to frequent relapses. This can predispose patients to repeated hospitalization resulting in significant economic impact. The objectives of this study were to examine real-world treatment patterns, costs and healthcare resource utilization for patients with these lymphomas, as well as identify disparities and risk factors associated with costs incurred in US hospitals. Methods: A retrospective study was conducted using the Premier Healthcare Database, a geographically diverse all-payer, hospital administrative database containing more than one billion inpatient and hospital-based outpatient encounters. Patients aged ≥18 years with at least 1 inpatient or 2 hospital-based outpatient visits with a MCL, WM, CLL, or MZL diagnosis, and who received treatment for these conditions from 1/1/2014 to 10/31/2019 were included in the study. Descriptive analysis was conducted to examine patient sociodemographic and hospital characteristics, all-cause and lymphoma-related healthcare resource utilization and costs. Costs were obtained from patients' discharge files and hospital billing records. Multivariable analysis was performed using generalized linear models to examine risk factors associated with costs and LOS for each lymphoma type. Treatment evaluated including any use of supportive care (blood transfusion, granulocyte colony stimulating factors [GCSF]), and by regimen (steroids alone, chemotherapy alone, chemo-immunotherapy, rituximab alone, targeted therapy alone, targeted therapy in combination with chemotherapy, other). Statistical significance was determined as a p-value of <0.05. Results: The study population included 23,952 CLL, 3,387 MCL, 2,655 MZL, and 1,811 WM patients in the US hospital database. Patients with WM were statistically significantly older (77 ± 58.5 years) compared to patients with CLL (74.2 ± 30.2 years), MCL (70.7 ± 37.3 years) or MZL (69.3 ± 33.8 years). More male (71.7%) and white (87.8%) patients were identified in the MCL cohort compared to the general lymphoma cohorts (Males: 58.7%; whites: 86.3). The most common comorbidities included chronic pulmonary disease (27.1%), gastroesophageal reflux disease (17.6%), moderate-severe renal disease (16.6%), congestive heart failure (15.7%) and diabetes without chronic complications (15.2%). Overall, more than two-thirds of patients in each lymphoma group received treatment with steroids alone during hospitalizations. While the use of steroids alone was higher among whites compared to non-white patients (69.5% vs. 60.4%), the use of chemo-immunotherapy was lower in whites compared to non-whites (11.9% vs. 16.2%). The average LOS of inpatient hospitalization ranged from 6.3 days for CLL to 7.4 days for MCL, with the mean costs per hospitalization from $19,566 (CLL) to $24,439 (MCL). Non-white patients have significantly longer mean LOS days compared with white patients (CLL: 18.3 vs. 14.8; MCL: 21.7 vs. 18.3; MZL: 21.6 vs. 18.5; WM 19.0 vs. 14.5). Across the 4 lymphoma types, multivariable regression confirmed the descriptive results and demonstrated that higher hospitals costs were associated with patients who were non-white, Hispanic/Latino, treated in hospitals located in the Northeast or West, or had Medicaid; statistically significant increased cost of care was also noted for patients who received targeted therapy or supportive care, such as blood transfusion or GCSF (Table 1). Conclusions: Real-world data demonstrated the significantly high total hospital costs once patients with MCL, WM, MZL, and CLL patients were hospitalized, with significantly higher impact to minority populations. Given the increased availability of effective oral therapeutics, optimal and timely disease control in the outpatients setting can potentially prevent or decrease hospitalizations and reduce economic burden on healthcare. Future studies are needed to explore the reason for admission, clinical outcomes, and potential preventive interventions. Figure 1 Figure 1. Disclosures Chanan-Khan: Alpha2 Pharmaceuticals: Patents & Royalties: Tabi; Ascentage, Starton, Cellectar, NonoDev, Alpha2 Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; BeiGene, Jansen, Ascentage: Honoraria; Cellectar: Current equity holder in publicly-traded company; Ascentage: Research Funding; Alpha2 Pharmaceuticals, NonoDev, Starton: Current holder of stock options in a privately-held company; BieGene, Jansen, Ascentage: Consultancy. Yang: BeiGene, Ltd.: Current Employment. Liu: BeiGene, Ltd.: Current Employment. Cao: Premier, Inc.: Current Employment; BeiGene, Ltd.: Consultancy. Baumer: BeiGene, Ltd.: Consultancy; Premier, Inc.: Current Employment. Krishnaswami: BeiGene, Ltd.: Consultancy; Premier, Inc.: Current Employment. Tang: BeiGene, Ltd.: Current Employment. Ailawadhi: Karyopharm: Consultancy; AbbVie: Consultancy; Genentech: Consultancy; Takeda: Consultancy; GSK: Consultancy, Research Funding; Xencor: Research Funding; Cellectar: Research Funding; Medimmune: Research Funding; Ascentage: Research Funding; Pharmacyclics: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; BeiGene, Ltd.: Consultancy; Sanofi: Consultancy; Oncopeptides: Consultancy.

Abstract Background: AHCT is a standard of care treatment for eligible patients (pts) with MM. Most consensus guidelines recommend that at the time of first AHCT, enough APBHC should be collected to perform two AHCT. However, recent studies have shown that with each decade after 1990, the use of cryopreserved APBHC for a salvage AHCT has declined and is now in the range of 4.6-15% in the decade between 2010-2018. The collection and storage of APBHC for two AHCT incurs additional costs and a prior single center cost analysis revealed that having had collected for just one AHCT in a cohort of 726 MM pts would have saved 3.8 million USD between 1993 and 2011. 1 Most centers that perform AHCT for MM pts continue to collect and store PBAHC for 2 AHCT. Herein we evaluate utilization trends and costs associated with cryopreserved APBHC in patients with MM. Methods: We retrospectively evaluated the clinicopathologic data from 440 patients with MM who underwent APBHC mobilization and collection at Mayo Clinic Florida between 2010 and 2019. The number of apheresis/collection sessions and APBHC product collection yields were determined for patients who were mobilized by any method. We estimated the costs involved in PBSC collection (apheresis) and cryopreservation storage based on our institution-specific charges as of May 2021. The cost of 1 session of APBHC collection/apheresis was $4,680 and the cost of 1 year of APBHC cryopreservation was $4,790 per patient. Statistical analysis was performed using JMP Pro 15 (SAS). Chi-square and Fischer exact tests were used to carry out univariate analysis for categorical variables and Wilcoxon rank sum/Kruskal Wallis for continuous variables. Results: Patient demographics are shown in Table 1. 440 pts underwent at least one collection session and 347 underwent at least 1 AHCT. The median number of mobilization sessions was 1 (95% CI 1.0-1.03), the median number of collection/apheresis sessions was 2.0 (95% CI 2.39-2.59), 84.3% (n=371) required ≥1 collection session. The median number of CD34 stem cells collected was 7.6 x10 6 (95% CI 7.76-8.19 x10 6), and the median number of infused CD34 cells was 4 x10 6(95% CI 4.13-4.37x10 6). The median cost of total collection sessions (defined as # of apheresis/collection sessions x $4,680) was $9,360 per pt (95% CI $11,181-$12,100). The median cost of cryopreservation (defined as # of years of storage x $4,790) was $19,160 per pt (95% CI $9,682-$22,252). The median number of years of storage was 4 (95% CI 4.11-4.65). 77(17.5%) pts have had APBHC in storage for <2 years, 218 (49.5%) have had APBHC in storage for 2-5 years, and 145 (33%) had have APBHC in storage for >5 years. The median time from MM diagnosis to AHCT was 9.0 months (range 13.8-18.5). 82% of patients collected enough APBHC (≥6x10 6, at least 3x10 6 per AHCT)for 2 AHCT. 8% of patients had all APBHC infused during their first AHCT, 83.5% had half of their APBHC infused during their first AHCT, and 8.1% had a different amount of APBHC infused during their first AHCT thus 91.6% of patients who collected APBHC had cells in storage. The median OS for the entire cohort after AHCT was 94.7 months (95% CI 88.6-100). Out of 347 patients who had stem cells in cryopreservation, 5 (1.4%) underwent a salvage AHCT and 3 (0.9%) underwent a tandem AHCT. 61% percent of patients had ≥1 excess collection sessions for APBHC that ultimately went unused. The median cost of excess collection sessions was $4,680 per pt (range, $4,680-$32,760) and the median total cost for excess collection sessions plus costs for storage was $23,840 per pt (range, $4,680-$85,450). The sum of costs of excess collection sessions was $2,077,920 and the sum of costs of cryopreservation was $5,812,665. Conclusion: The results of this single center analysis show that only 1.4% of patients underwent a salvage AHCT between 2010 and 2019 while 91.6% had APBHC left in storage which confirms the increase in storage of cryopreserved APBHC and declining trend in the use of stored APBHC for salvage AHCT in pts with MM. This is likely due to the advent of next generation novel therapies such as monoclonal antibodies, proteasome inhibitors and immunomodulatory agents. Excess collections, and cryopreservation of unused APBHC incur a cost of nearly $8 million. Institutional policies regarding universal APBHC collection and long-term storage should be reevaluated. 1Phipps C, et al. Bone Marrow Transplantation 2015:50;663-667. Figure 1 Figure 1. Disclosures Murthy: CRISPR Therapeutics: Research Funding. Ailawadhi: Sanofi: Consultancy; Medimmune: Research Funding; Genentech: Consultancy; Ascentage: Research Funding; Pharmacyclics: Consultancy, Research Funding; Xencor: Research Funding; Janssen: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; AbbVie: Consultancy; Beigene: Consultancy; GSK: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Takeda: Consultancy; Cellectar: Research Funding; Karyopharm: Consultancy.

Abstract Background: Self-reported financial hardship (FH) amongst cancer patients is increasingly becoming a challenge for patients, caregivers, and healthcare providers. FH not only leads to financial struggles, significant lifestyle changes, and emotional distress, but also contributes to treatment noncompliance, affecting clinical outcomes. As treatment costs rise, it is crucial to develop efficient methods to proactively identify and alleviate FH in hematology practice. One potential approach is utilizing automated processes to identify those at highest risk of FH. At Mayo Clinic, screening for FH involves using a single financial strain question 'How hard is it for you to pay for the very basics like food, housing, medical care, and heating?' which all cancer patients answer annually as part of the institution's Social Determinants of Health (SDOH) assessment. Answers are on a five-point scale including not hard at all, not very hard, somewhat hard, hard, and very hard. In this study, we assess the prevalence and predictors for FH (denoted by a response of "Very hard" "Hard" or "Somewhat hard") amongst the Mayo Clinic hematologic malignancy patient population. Our study objective was to determine if this automated process could identify those at risk for FH. Methods: Patients who received care for hematologic malignancies (lymphoma, leukemia, plasma disorders, myelodysplastic/myeloproliferative disorders, and other heme malignancies) at any of the Mayo Clinic cancer centers (Minnesota, Arizona, and Florida) and who had completed the SDOH screen at least once were included in this study. The electronic medical record (EMR) and Mayo Clinic Cancer Registry were utilized to extract demographic and disease variables. Patient's home zip code was used to determine rural/urban residence, distance from cancer center, and the Area Deprivation Index (ADI), a measure of socioeconomic disadvantage based on home zip code (ranging from 1-100, with 100 representing the most disadvantaged). Multivariable logistic regression modeling was used to examine predictor variables for FH in this patient population. Results: The final cohort included 10,024 patients from 2018 to 2020. Median age was 64.6 years (IQR 58.1,73.7), 58% were male, and 79% married. Race/ethnicity composition was 94% White (n=9,268), 2.5% Black (n=246), 0.4% American Indian/Alaskan Native (44), and 4% Hispanic (n=360). Fifty-six percent of patients had Medicare and 41% had commercial insurance. Fifty percent were retired, 40% were working/students, and 72% were urban residents. Mean ADI was 41.2. Fifty-six percent of patients had lymphomas, 23.5% had plasma cell disorders, 8.5% had leukemias, 6.8% had other hematological malignancies, and 5.5% had myelodysplastic/myeloproliferative neoplasms. FH was reported by 12.8% (n=1286) of the patients. Table 1 shows the results of the multivariable model. A significantly higher likelihood of endorsing FH was noted in Hispanic vs non-Hispanics, Black and American Indian/Alaskan Native groups vs whites, Disabled/Unemployed vs working, Medicaid, Medicare, and Self-Pay groups vs commercial insurance, higher ADI (5 th quintile vs 1 st), and myelodysplastic/myeloproliferative disorder and other hematologic malignancy vs lymphoma patients. Older age, being retired, and living farther from the cancer center were associated with significantly less likelihood of endorsing FH. Conclusion: Our study used automated data extraction from the EMR to efficiently identify predictors of FH in hematologic cancer patients. Employing a dichotomized and automated "flag" for FH, particularly if incorporated in the EMR, could ease the identification of SDOH issues, facilitate timely connection to appropriate resources, and help provide better patient-centered care. Figure 1 Figure 1. Disclosures Ailawadhi: Sanofi: Consultancy; Cellectar: Research Funding; Karyopharm: Consultancy; Ascentage: Research Funding; Genentech: Consultancy; Janssen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Beigene: Consultancy; GSK: Consultancy, Research Funding; AbbVie: Consultancy; Medimmune: Research Funding; Pharmacyclics: Consultancy, Research Funding; Takeda: Consultancy; Amgen: Consultancy, Research Funding; Xencor: Research Funding. Fonseca: OncoTracker: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; BMS: Consultancy; Mayo Clinic in Arizona: Current Employment; Aduro: Consultancy; AbbVie: Consultancy; GSK: Consultancy; Merck: Consultancy; Juno: Consultancy; Scientific Advisory Board: Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Patent: Prognosticaton of myeloma via FISH: Patents & Royalties; Novartis: Consultancy; Bayer: Consultancy; Celgene: Consultancy; Caris Life Sciences: Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy; Janssen: Consultancy; Amgen: Consultancy; Pharmacyclics: Consultancy; Sanofi: Consultancy. Griffin: Exact Sciences: Research Funding.

Abstract Background: Despite many treatment options, multiple myeloma (MM) remains largely incurable with poor outcomes among patients who progress after treatment with a protease inhibitor, immunomodulatory imide drugs (IMiDs), and/or an anti-CD38 antibody. Multiple targeted therapies have been developed for different subtypes of non-Hodgkin lymphoma (NHL); however, these therapies are typically not curative for patients with relapsed/refractory (R/R) disease. IMiDs are a standard of care for treatment of MM and have shown activity in some NHL subtypes. However, given that many patients treated with these agents frequently develop disease progression, an unmet need remains. CFT7455 is a next-generation IKZF1/3 degrader, which is more potent and catalytically active than other approved agents targeting the cereblon E3 ligase complex that degrade IKZF1/3. CFT7455 is orally bioavailable and selective for IKZF1 (Ikaros) and IKZF3 (Aiolos). Depletion of these targets from malignant B cells result in tumor cell death, and depletion from the tumor microenvironment results in T-cell activation. In i n vitro and in vivo models of MM and NHL, including anaplastic large cell lymphoma, diffuse large B-cell lymphoma, and mantle cell lymphoma (MCL), CFT7455 demonstrated greater activity than other agents in similar classes. These results provided rationale for a first-in-human, phase 1 study to evaluate CFT7455. Study Design: This is an open-label, multicenter, phase 1 clinical trial with dose escalation and dose expansion phases. The dose escalation phase, beginning with a starting dose of 50 mcg daily, may include single-participant cohorts at initial dose levels, after which 3-6 patients are enrolled per cohort using a Bayesian logistic regression model. After initial exploration of single-agent CFT7455 in a mixed cohort of patients with R/R MM or select NHLs, dose escalation is split to perform dose determination in R/R MM separate NHL. Once a safe dose of CFT7455 in R/R MM is determined, the combination of CFT7455 with dexamethasone will be explored in R/R MM. CFT7455 is dosed orally in 28-day cycles, on a 21-day on, 7-day off schedule, until disease progression or intolerable toxicity. Expansion cohorts of single-agent CFT7455 and CFT7455 plus dexamethasone in R/R MM, and single-agent CFT7455 for peripheral T-cell lymphoma and MCL are planned. Primary objectives include: safety and tolerability, randomized phase 2 dose (RP2D)/maximum tolerated dose (MTD) of CFT7455, and estimation of antitumor activity of CFT7455. Secondary objectives include assessment of pharmacokinetics. Exploratory objectives include characterization of target engagement and IKZF1/3 degradation and assessing the immunomodulatory effects of CFT7455. For MM patients, key inclusion criteria include histologically/cytologically-confirmed MM that is R/R. Patients must not be candidates for regimens known to provide clinical benefit, defined as having received ≥3 prior anti-myeloma regimens including ≥2 consecutive cycles of lenalidomide, pomalidomide, a proteasome inhibitor, a glucocorticoid, and an anti-CD38 antibody. Key exclusion criteria include the presence of central nervous system malignancy, recent venous thromboembolism or inability to undergo its prophylaxis. Plasma cell leukemia is excluded. For NHL patients, key inclusion criteria include histologically/cytologically-confirmed NHL that is R/R. Patients mustn't be candidates for regimens known to provide clinical benefit, defined as the requisite prior lines of therapy according to an indication-specific basis. Key exclusion criteria include the presence of central nervous system malignancy, recent venous thromboembolism or inability to undergo its prophylaxis. Several lymphoma subtypes less likely to benefit are excluded (eg, Richter transformation, Burkitt lymphoma, Sezary syndrome, and lymphoblastic lymphoma). Approximately 164 patients at approximately 13 US sites will be enrolled. This trial is registered with clinicaltrials.gov as NCT04756726, enrollment is ongoing. Disclosures Berdeja: Legend Biotech: Consultancy; Incyte: Research Funding; Ichnos Sciences: Research Funding; Genentech: Research Funding; GlaxoSmithKline: Research Funding; Lilly: Research Funding; SecuraBio: Consultancy; EMD Serono: Research Funding; Janssen: Consultancy, Research Funding; Bluebird bio: Consultancy, Research Funding; Amgen: Research Funding; Astex Pharmaceuticals: Research Funding; Kite Pharma: Consultancy; CRISPR Therapeutics: Consultancy, Research Funding; Celularity: Research Funding; Celgene: Consultancy, Research Funding; Poseida: Research Funding; Acetylon: Research Funding; Teva: Research Funding; Novartis: Research Funding; BMS: Consultancy, Research Funding; Sanofi: Research Funding; Abbvie: Research Funding; Takeda: Consultancy. Ailawadhi: GSK: Consultancy, Research Funding; Sanofi: Consultancy; Cellectar: Research Funding; Janssen: Consultancy, Research Funding; Xencor: Research Funding; Beigene: Consultancy; Karyopharm: Consultancy; BMS: Consultancy, Research Funding; Ascentage: Research Funding; Pharmacyclics: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; AbbVie: Consultancy; Takeda: Consultancy; Genentech: Consultancy; Medimmune: Research Funding. Horwitz: Millennium /Takeda: Consultancy, Research Funding; Kura Oncology: Consultancy; Janssen: Consultancy; Tubulis: Consultancy; Myeloid Therapeutics: Consultancy; Affimed: Research Funding; Aileron: Research Funding; Vividion Therapeutics: Consultancy; ONO Pharmaceuticals: Consultancy; Celgene: Research Funding; Acrotech Biopharma: Consultancy; Daiichi Sankyo: Research Funding; Forty Seven, Inc.: Research Funding; Trillium Therapeutics: Consultancy, Research Funding; C4 Therapeutics: Consultancy; Kyowa Hakko Kirin: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; SecuraBio: Consultancy, Research Funding; Shoreline Biosciences, Inc.: Consultancy; ADC Therapeutics: Consultancy, Research Funding; Verastem: Research Funding. Matous: Pharmacyclics: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Mehta-Shah: C4 Therapeutics: Consultancy; Kiowa Hakko Kirin: Consultancy; Karyopharm: Consultancy; Ono Pharmaceuticals: Consultancy; Secura Bio: Consultancy, Research Funding; Daiichi Sankyo: Consultancy, Research Funding; AstraZeneca: Research Funding; Bristol Myers Squibb: Research Funding; Celgene: Research Funding; Innate Pharmaceuticals: Research Funding; Roche/Genentech: Research Funding; Corvus Pharmaceuticals: Research Funding; Verastem: Research Funding. Martin: GlaxoSmithKline: Consultancy; Sanofi: Research Funding; Oncopeptides: Consultancy; Amgen: Research Funding; Janssen: Research Funding. Richardson: Takeda: Consultancy, Research Funding; Sanofi: Consultancy; Secura Bio: Consultancy; Oncopeptides: Consultancy, Research Funding; GlaxoSmithKline: Consultancy; Regeneron: Consultancy; Protocol Intelligence: Consultancy; AstraZeneca: Consultancy; Karyopharm: Consultancy, Research Funding; Celgene/BMS: Consultancy, Research Funding; AbbVie: Consultancy; Janssen: Consultancy; Jazz Pharmaceuticals: Consultancy, Research Funding. Richard: Karyopharm, Janssen: Honoraria. Bhutani: Sanofi: Consultancy; Amgen, BMS, Takeda: Speakers Bureau; Janssen, MedImmune, Takeda, Celgene, BMS, Cerecor, Celularity: Research Funding. Yee: Takeda: Consultancy; Adaptive: Consultancy; Karyopharm: Consultancy; Bristol Myers Squibb: Consultancy; Oncopeptides: Consultancy; GSK: Consultancy; Amgen: Consultancy; Sanofi: Consultancy; Janssen: Consultancy. Palmer: C4 Therapeutics: Current Employment. Gorman: C4 Therapeutics: Current Employment. Schoenborn-Kellenberger: C4 Therapeutics: Current Employment. Bilic: C4 Therapeutics: Current Employment. Crystal: C4 Therapeutics: Current Employment, Current equity holder in publicly-traded company. Mahler: C4 Therapeutics: Current Employment, Current equity holder in publicly-traded company. Lonial: Merck: Honoraria; Abbvie: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Honoraria, Research Funding; AMGEN: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; GlaxoSmithKline: Consultancy, Honoraria, Research Funding.

Abstract Background: Phospholipid ethers (PLE) provide a novel mechanism to target tumor cells. Tumor cells contain increased amounts of lipid rafts in their cell membranes, which are thought to enhance signaling and resist apoptosis. Phospholipid drug conjugates (PDC) are specifically designed to have high affinity for lipid rafts which upon binding results in trans-membrane inversion with the ability to deliver an attached therapeutic directly to the cytosol. Iopofosine I-131 (formerly identified as CLR 131) is a novel PDC delivering I-131 as a targeted tumor cell radiotherapy. Iopofosine I-131 is being examined in relapsed or refractory multiple myeloma (RRMM) patients through an open-label, Phase 2 trial, CLOVER-1 (NCT02952508). Methods: The primary objective of this study is to determine the safety and efficacy of Iopofosine I-131 in heavily pretreated MM patients. Eligibility criteria for MM patients include progression or relapsed disease that is refractory to at least 1 proteasome inhibitor and 1 immunomodulatory agent unless intolerable/ineligible to receive such agents with no upper limit to the number of prior lines of therapy. Iopofosine I-131 is administered in up to 4 IV infusions (15-20 min) over 3 months, with doses given 1-2 weeks apart each cycle for a maximum of 2 cycles, along with dexamethasone 40 mg weekly (20 mg in patients > 75), for up to 12 weeks. Following iopofosine I-131 administration, no other antineoplastic or targeted therapy was given until clinically indicated by the investigator. Adverse events (AEs) are graded by NCI-CTCAE v4.03; responses are assessed by the 2016 International Myeloma Working Group criteria. Results: Eleven patients with at least triple class refractory (immunomodulatory agent, proteasome inhibitor and monoclonal antibody) MM have been enrolled in this Phase 2 study with data current as of 28 May 2021. Patients had a median age of 72 (range 34-77), mean prior regimens of 7.2 (range 3-17) and received a mean total body dose of 75.4 mCi (range 59.7-118.7) of iopofosine I-131. The overall response rate (ORR) was 45.5% (5/11), the clinical benefit rate (CBR) was 72.7% (8/11) and disease control rate (DCR) was 100%. Median progression free survival (PFS) was 3.4 months. In a subset of patients who are quad/penta drug refractory, efficacy increased with an ORR of 80.0% (4/5) and CBR of 100% (5/5). The primary treatment emergent AEs in patients with MM included cytopenias (87.5%), in line with prior experience with iopofosine I-131. The most commonly observed cytopenias included Grade 3 or 4 thrombocytopenia (62.5%), anemia (62.5%), neutropenia (62.5%) and decreased white blood cell count (50%). There were no infusion-related reactions or AEs. Conclusions: Initial results for iopofosine I-131 show efficacy with a promising ORR of 45.5% and a CBR or 72.7% in heavily pretreated triple class refractory multiple myeloma patients. Interestingly, iopofosine I-131 showed its highest efficacy in patients that were quad/penta drug refractory with ORR of 80%, highlighting its potential as a later line therapy. Iopofosine I-131 is a novel cancer radiotherapeutic that may provide benefit to patients that are refractory/unresponsive to traditional MM therapies. CLOVER-1 is actively enrolling MM patients that are at least triple class refractory across the United States. Disclosures Ailawadhi: AbbVie: Consultancy; Pharmacyclics: Consultancy, Research Funding; Ascentage: Research Funding; Cellectar: Research Funding; GSK: Consultancy, Research Funding; Genentech: Consultancy; BMS: Consultancy, Research Funding; Karyopharm: Consultancy; Sanofi: Consultancy; Medimmune: Research Funding; Janssen: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Xencor: Research Funding; Takeda: Consultancy; Beigene: Consultancy. Stiff: CRISPR: Consultancy; Gamida-Cell, Atara, Amgen, Incyte, Takeda, Macrogenetics, Eisai: Research Funding; Cellectar: Research Funding. Green: Seagen Inc.: Research Funding; bristol myers squibb: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Cellectar Biosciences: Research Funding; GSK: Membership on an entity's Board of Directors or advisory committees; Janssen Biotech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno Therapeutics: Patents & Royalties, Research Funding; Legend Biotech: Consultancy; Neoleukin Therapeutics: Membership on an entity's Board of Directors or advisory committees; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; SpringWorks Therapeutics: Research Funding. Lipe: Seagen Inc.: Research Funding; BMS: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; sanofi: Consultancy; GlaxoSmithKline: Consultancy; amgen: Research Funding; Cellectar: Research Funding; Karyopharm: Research Funding; Harpoon: Research Funding. Cull: Aptevo: Research Funding. Friend: Cellectar: Current Employment. Longcor: Cellectar: Current Employment. Oliver: Cellectar: Current Employment.

Abstract INTRODUCTION Sparse data exist regarding I+V in an off-trial setting, particularly in patients (pts) with progression of disease on either I or V as single agent treatment. The 1-year overall survival (OS) rates with V monotherapy following I range from 75%-91% (Eyre et al, BJH 2019; Jones et al, Lancet Oncol 2018); however, longer-term follow-up of these or other patient cohorts treated with V after I has not yet been reported. Effective options in double-refractory pts are lacking when a clinical trial is not feasible. Here, we report our experience with I+V in these patient groups. METHODS After IRB approval, we reviewed the records of pts seen at Mayo Clinic (between 4/2012-1/2021) who received I+V therapy off-trial for CLL progression. Pts treated with I+V for Richter's transformation were excluded. Time to next treatment (TTNT) was measured from I+V treatment start date to the date of next treatment start or last known treatment status with death as a competing risk. OS was measured from I+V start date until date of death or when the patient was last known alive; OS was analyzed using the Kaplan-Meier method and Cox proportional hazards model. RESULTS Thirty-three pts with progressive CLL were treated with I+V (median duration 13.3 months [95% CI: 7.1 months-not estimable (NE)]). The median age was 70 years (range 47-86), 6 (18%) were women, and 20 (65%) had del(17p) or TP53 mutation. The median number of prior lines of therapy was 3 (range 1-15). Additional characteristics at the time of I+V start are shown in Table 1. Median follow-up from start of I+V was 23.8 months. Among 22 pts with prior progression on I only (V-naïve), the median duration of I+V was 14.8 months (95% CI 7.6 months-NE). The median duration on either I or V from the start of combination was 20.3 months (95% CI 8.3 months-NE). The median TTNT was 25.1 months (Figure 1A). Four pts proceeded to cellular therapy (alloSCT [n=3], CAR-T [n=1]) while on I+V. Next therapy (n=9) consisted of Richter transformation treatment (n=2), chemotherapy plus continued I+V (n=1), anti-CD20 plus continued I+V (n=1), duvelisib + I (n=1), TP-0903 + I (n=1), reintroduction of I at disease progression after previously stopping I during I+V therapy (n=1), and reintroduction of I (n=1) or V (n=1) at disease progression after previously stopping I+V. Of 9 pts who did not receive subsequent therapy, 4 pts remain on I+V (median duration 16.4 months), 4 pts continued V after discontinuing I (median duration on V from start of I+V was 21.5 months), and 1 pt discontinued I+V following a second cancer diagnosis and died without receiving additional CLL-directed treatment. Eleven pts received I+V in the double-refractory setting; 9 pts had prior disease progression on sequential I then V and 2 pts had prior disease progression on sequential V then I. The median duration of I+V was 7.5 months (95% CI 4.3 months-NE), and the median duration of either agent from I+V start was 10.8 months (95% CI 7.1 months-NE). The median TTNT was 14.0 months (Figure 1A). Eight pts required additional treatment, consisting of PI3K inhibitor (n=2), anti-CD20 added to I+V (n=1), CAR-T (n=1), anti-CD20 with (n=1) or without (n=1) bendamustine added to continued I, and Richter transformation treatment (n=2). One pt continues I+V (17.4 months ongoing) without further treatment. Two pts died from disease progression without receiving additional treatment. The median OS of all 33 pts was 27.4 months (95% CI 25.9 months-NE; Figure 1B). The median OS of the 22 pts with prior progression on I (V-naïve) was 47.1 months (95% CI 27.7 months-NE), and the median OS of the 11 pts with prior progression on I and V separately was 27.0 months (95% CI 15.5 months-NE). In univariate analyses, prior progression on V was a predictor of shorter OS (HR=3.9; 95% CI 1.4-11.2; p=0.01). CONCLUSIONS Combination I+V therapy in heavily pre-treated CLL pts who have disease progression after I provides durable benefit with a median OS approaching 4 years. In the double-refractory setting, repurposing both drugs as combination I+V therapy can be a useful strategy, despite the short-term disease control, for pts where clinical trial options are limited or not available. Further examination of these approaches in larger cohorts and understanding the operative resistance mechanisms in pts with double-refractory disease are key next studies. Figure 1 Figure 1. Disclosures Ding: Octapharma: Membership on an entity's Board of Directors or advisory committees; DTRM: Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding. Chanan-Khan: BeiGene, Jansen, Ascentage: Honoraria; Ascentage, Starton, Cellectar, NonoDev, Alpha2 Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Alpha2 Pharmaceuticals: Patents & Royalties: Tabi; Ascentage: Research Funding; Cellectar: Current equity holder in publicly-traded company; Alpha2 Pharmaceuticals, NonoDev, Starton: Current holder of stock options in a privately-held company; BieGene, Jansen, Ascentage: Consultancy. Kenderian: Humanigen, Inc.: Consultancy, Honoraria, Research Funding. Wang: TG Therapeutics: Membership on an entity's Board of Directors or advisory committees; MorphoSys: Research Funding; Novartis: Research Funding; LOXO Oncology: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Research Funding; Incyte: Membership on an entity's Board of Directors or advisory committees, Research Funding; InnoCare: Research Funding; Eli Lilly: Membership on an entity's Board of Directors or advisory committees. Ailawadhi: Pharmacyclics: Consultancy, Research Funding; Xencor: Research Funding; Janssen: Consultancy, Research Funding; Cellectar: Research Funding; Sanofi: Consultancy; BMS: Consultancy, Research Funding; GSK: Consultancy, Research Funding; Ascentage: Research Funding; Medimmune: Research Funding; Karyopharm: Consultancy; Amgen: Consultancy, Research Funding; Beigene: Consultancy; AbbVie: Consultancy; Takeda: Consultancy; Genentech: Consultancy. Koehler: AbbVie: Membership on an entity's Board of Directors or advisory committees; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees. Kay: AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Targeted Oncology: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Juno Therapeutics: Membership on an entity's Board of Directors or advisory committees; Genentech: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Research Funding; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Sunesis: Research Funding; Rigel: Membership on an entity's Board of Directors or advisory committees; Acerta Pharma: Research Funding; CytomX Therapeutics: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Research Funding; Behring: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Tolero Pharmaceuticals: Research Funding. Parikh: Pharmacyclics, MorphoSys, Janssen, AstraZeneca, TG Therapeutics, Bristol Myers Squibb, Merck, AbbVie, and Ascentage Pharma: Research Funding; Pharmacyclics, AstraZeneca, Genentech, Gilead, GlaxoSmithKline, Verastem Oncology, and AbbVie: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Combination ibrutinib and venetoclax in patients with relapsed CLL.

Abstract Background: PD-(L)1 pathway inhibitors have demonstrated durable clinical benefit in both solid tumors and hematologic malignancies; however, as less than 1/3 of patients respond to anti-PD-(L)1 monotherapy, combination therapies may be needed for improved response rates and survival. T cell Immunoglobulin and ITIM domain (TIGIT) is expressed on activated T cell and natural killer (NK) cell subsets; TIGIT-CD155 binding suppresses T and NK cell function and inhibits the antitumor immune response. AB308, an Fc-enabled anti-TIGIT humanized IgG1 monoclonal antibody (mAb), has reversed TIGIT-CD155-mediated T cell inhibition in preclinical models. ARC-12 will assess whether TIGIT pathway blockade by AB308 can augment zimberelimab (zim; anti-PD-1 mAb) activity in patients with solid and hematologic malignancies. Study Design and Methods: ARC-12 is a phase 1/1b, first-in-human, open-label, dose-escalation study of AB308 + zim in patients with advanced solid tumors or hematologic malignancies. Dose expansion cohorts include relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). For the dose-escalation, eligible adults have solid tumors for which no standard-of-care therapy exists or have pathologically-confirmed R/R non-Hodgkin lymphoma (NHL) and have not received or are ineligible for allogeneic stem cell transplant or adoptive cell transfer; ≤5 lines of prior systemic therapy; ≥1 measurable lesion per RECIST (solid tumors) or Lugano Classification (NHL) criteria; and ECOG performance score of 0-1. As shown in the figure, patients will receive AB308 + zim intravenously (IV) once every 3 weeks (Q3W; Part A) or once every 4 weeks (Q4W; Part B). In Part A, the first 6 patients of Cohort 1 will follow 3+3+6 rules, allowing for AB308 dose adjustment if dose-limiting toxicities (DLTs) warrant; all other dose-escalation cohorts will use 3+3 rules. After the Cohort 2 DLT period has been cleared, Part B enrollment will begin in parallel with Part A to determine the recommended dose for expansion (RDE) for AB308 + zim for both the Q3W (Part A) and Q4W (Part B) schedules. Each part can independently proceed to dose-expansion once the RDE is determined for that dose schedule. In the dose-expansion, patients will be enrolled into disease-specific cohorts for non-small cell lung cancer (NSCLC), melanoma, gastrointestinal cancer, cervical cancer, and hematologic malignancies (DLBCL or MM). AB308 + zim may be dosed on either a Q3W or Q4W schedule; all patients in each expansion cohort will receive the same dose schedule. For both the dose-escalation and dose-expansion, the primary endpoints assess safety and tolerability of AB308 + zim; secondary endpoints include pharmacokinetics (PK), immunogenicity, and objective response rate for AB308 + zim. Additional secondary endpoints in the dose-expansion are disease control rate and duration of response. Safety and efficacy data will be analyzed using summary statistics and Kaplan Meier estimates as appropriate; PK parameters will be estimated using noncompartmental methods. ARC-12 is actively recruiting at sites in the United States (NCT04772989). Figure 1 Figure 1. Disclosures Ailawadhi: Pharmacyclics: Consultancy, Research Funding; Takeda: Consultancy; Sanofi: Consultancy; Amgen: Consultancy, Research Funding; Ascentage: Research Funding; Genentech: Consultancy; AbbVie: Consultancy; BMS: Consultancy, Research Funding; Xencor: Research Funding; Janssen: Consultancy, Research Funding; Medimmune: Research Funding; Cellectar: Research Funding; Karyopharm: Consultancy; Beigene: Consultancy; GSK: Consultancy, Research Funding. Foster: Arcus Biosciences, Inc.: Current Employment. Ryba: Arcus Biosciences, Inc.: Current Employment. Scharville: Arcus Biosciences, Inc.: Current Employment. El-Baghdady: Arcus Biosciences, Inc.: Current Employment. OffLabel Disclosure: AB308 and zimberelimab (AB122) are in clinical development and are not approved in the United States for the use under discussion.

Abstract Introduction: Melphalan flufenamide (melflufen) is a first-in-class peptide-drug conjugate that targets aminopeptidases and rapidly releases alkylating agents into tumor cells. The single-arm, open-label, Phase 2 HORIZON study (NCT02963493), conducted in Europe and the USA, demonstrated in patients with heavily pre-treated relapsed/refractory multiple myeloma (RRMM), including those with triple-class-refractory and extramedullary disease, that melflufen in combination with dexamethasone showed clinically meaningful efficacy and a manageable safety profile (Richardson PG, et al. J Clin Oncol. 2021;39:757-767). Comparative trials between all regimens/agents are not feasible, and hence, real-world datasets may be valuable to allow the comparison of patient outcomes in single-arm clinical trials with similar patient populations in the real world. The objective of the REAL-world Myeloma (REALM) study was to compare clinical outcomes between patients in the COTA database and those of patients in the HORIZON study in order to compare routine care with melflufen. Methods: REALM is a retrospective, observational study using real-world data from 605 patients with RRMM collected in the COTA database, a USA-based real-world evidence database comprising longitudinal, Health Insurance Portability and Accountability Act (HIPAA)-compliant data on the diagnosis, clinical management, and outcomes of patients with cancer. Patients in REALM met the main HORIZON eligibility criteria (aged ≥18 years; ≥2 lines of prior therapy [including an immunomodulatory drug and a proteasome inhibitor]; refractory to pomalidomide and/or daratumumab on or after January 1, 2015; and received a line of therapy after meeting the inclusion criteria). Propensity score (PS) matching is a commonly used approach for comparing the effectiveness of 2 treatment options across different studies where individual patient data are available for both treatments. This abstract presents adjusted clinical outcome results based on 1:1 PS matching of patients in the COTA and HORIZON datasets for 12 covariates (COTA PS and HORIZON PS, Table 1). These covariates were considered important because they reflect patient characteristics that impact clinical outcomes and were validated in a feasibility study, and by independent experts. The primary endpoint of the HORIZON study was overall response rate. The primary endpoints of the REALM study were time to treatment discontinuation (TTD) and time to next treatment (TTNT), to mitigate against missing treatment response data in the COTA database identified in the feasibility study. Results: Selected patient demographic and clinical characteristics were generally well matched (Table 1) between patients from COTA PS (n=110) and HORIZON PS (n=110), except for the Eastern Cooperative Oncology Group performance status, which was better in the COTA PS dataset than in the HORIZON PS dataset. Patients in both the COTA PS and the HORIZON PS datasets were predominantly male and White. Patients had a median age of 67 years in the COTA PS dataset and 64 years in the HORIZON PS dataset, with a median of 4 and 5 prior lines of therapy, respectively. The median time since first diagnosis to index data was 60.19 months in the COTA PS dataset and 72.56 months in the HORIZON PS dataset. The median TTNT (95% confidence interval [CI]) in the COTA PS dataset versus the HORIZON PS dataset was 4.6 (3.7-6.9) months and 5.9 (4.7-7.7) months, respectively (p=0.949). The median TTD (95% CI) in the COTA PS dataset versus the HORIZON PS dataset was 3.2 (2.6-3.9) months and 3.9 (3.0-4.6) months, respectively (p=0.642). Conclusions: Pharmacoepidemiologic methods using individual patient data play an important role in evaluating the effectiveness of treatments in the absence of randomized controlled trial data. Patients with RRMM receiving melflufen in combination with dexamethasone noted a trend toward improved TTNT and TTD compared with corresponding real-world treatment approaches. This benefit may be clinically meaningful especially in the triple-class-refractory patient population, which remains an unmet need in RRMM. Figure 1 Figure 1. Disclosures Ailawadhi: Karyopharm: Consultancy; AbbVie: Consultancy; Genentech: Consultancy; Takeda: Consultancy; GSK: Consultancy, Research Funding; Xencor: Research Funding; Cellectar: Research Funding; Medimmune: Research Funding; Ascentage: Research Funding; Pharmacyclics: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; BeiGene, Ltd.: Consultancy; Sanofi: Consultancy; Oncopeptides: Consultancy. Wang: COTA, Inc.: Current Employment, Other: Equity ownership. Belli: COTA, Inc.: Current Employment, Other: Equity ownership. Jansson Blixt: Oncopeptides: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company. Cripps: Oncopeptides: Other: Independent consultant. Zavisic: Oncopeptides: Current Employment, Current holder of stock options in a privately-held company. Ramasamy: Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Conference registration, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Conference registration, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Conference registration, Research Funding; Celgene (BMS): Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Conference registration, Research Funding; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive biotech: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer oncology: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract Introduction: Clinical availability of highly effective novel agents (including Bruton tyrosine kinase [BTK] and B-cell lymphoma 2 [BCL-2] inhibitors) is rapidly altering the therapeutic landscape of chronic lymphocytic leukemia (CLL) necessitating a review of treatment guidelines. However, there is limited real-world data to validate if the availability of these novel agents has translated to a true shift in treatment paradigm for patients treated in the community. As the majority of CLL patients are treated in non-academic community-based settings, we investigated the clinical adoption trends of commercially available FDA approved novel agents for treatment of CLL patients. In addition, given that the COVID-19 pandemic led to major alteration in clinical oncology practices, we further studied if this contributed to an alteration in the selection of therapeutic agents resulting in changes of CLL treatment patterns and the utilization of novel agents in the real-world setting. Thus, the objectives of this study were to examine the utilization pattern of various CLL therapies, as well as evaluate the pattern of adoption of novel agents for treatment and the impact of COVID. Methods: A retrospective observational study was conducted using the Flatiron Health database that comprised EHR-derived de-identified data. Adult patients (≥18 years) with newly diagnosed CLL from January 2014 to May 2021, with no prior treatment and who were continuously enrolled for at least 6 months before and 3 months after the index date, defined as the first date of CLL/SLL diagnosis were included. Treatment regimens were classified into seven mutually exclusive categories: bendamustine-based chemotherapy, other chemotherapy, anti-CD20-based therapy, ibrutinib, idelalisib, acalabrutinib and venetoclax. Further treatment categorization included chemotherapy vs. targeted therapy, and traditional IV vs. novel oral agents. The impact of the pandemic was examined by comparing the pre- and post-COVID cohorts (defined as 15 months pre- and post- of March 1, 2021). Descriptive analyses were conducted to examine the frequency of use of treatment regimens by quarter in each year, line of therapy and between different age, gender, US geographical region, insurance status, and race/ethnicity subgroups. Multivariable regression was conducted to examine factors associated with the likelihood of adoption of novel and oral agents. Statistical significance was determined at a p-value of less than 0.05. Results: A total of 3,037 newly diagnosed CLL patients (median age =73) were included in the study. Over half were male (62.3%), white (74.6%) and commercially-insured (54.1%). Patients were primarily treated in community practices (92%). Overall, a significant trend in adoption of novel agents was observed throughout the years following their approval (Figure 1A). Across the evaluation period, a significant decrease in chemotherapy use was observed from 61.3% (quarter 1, 2014) to 20% (quarter 2, 2021) in favor of targeted therapy as first-line therapy (Figure 1B). In contrast, the utilization of novel oral agents (vs. traditional IV agents) for first-line therapy increased from 9.5% to 70.9% for the same period (Figure 1C). Similar trends were observed for second-line and third-line therapies. Encouragingly, this change in treatment patterns was adopted comparably in all sociodemographic subgroups with no evidence of disparity. While there was no statistically significant difference between the pre- and post-COVID treatment landscape, the adoption of target and novel oral agents has been more pronounced with the COVID pandemic. Conclusions: Results from real-world data suggest that there is a clear shift towards the adoption of novel therapies with preference given to targeted agents and oral therapies in the US since 2014. Further research examining real-world outcomes associated with treatment regimens are needed to inform decision makers. Figure 1 Figure 1. Disclosures Chanan-Khan: Cellectar: Current equity holder in publicly-traded company; Alpha2 Pharmaceuticals, NonoDev, Starton: Current holder of stock options in a privately-held company; Ascentage: Research Funding; Alpha2 Pharmaceuticals: Patents & Royalties: Tabi; Ascentage, Starton, Cellectar, NonoDev, Alpha2 Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; BeiGene, Jansen, Ascentage: Honoraria; BieGene, Jansen, Ascentage: Consultancy. Yang: BeiGene, Ltd.: Current Employment. Liu: BeiGene, Ltd.: Current Employment. Zimmerman: BeiGene, Ltd.: Current Employment. Tang: BeiGene, Ltd.: Current Employment. Ailawadhi: Karyopharm: Consultancy; AbbVie: Consultancy; Genentech: Consultancy; Takeda: Consultancy; GSK: Consultancy, Research Funding; Xencor: Research Funding; Cellectar: Research Funding; Medimmune: Research Funding; Ascentage: Research Funding; Pharmacyclics: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; BeiGene, Ltd.: Consultancy; Sanofi: Consultancy; Oncopeptides: Consultancy.