Ailawadhi, Sikander

Extramedullary multiple myeloma is seen in advanced and aggressive disease and occurs due to plasma cell infiltration of sites other than the bone marrow. Myelomatous ascites or pleural effusion is seen in less than 1 % of cases and can be differentiated from infectious etiologies based on fluid cytology.

Abstract Introduction: Treatment resistance remains a challenge that most patients (pts) with MM will encounter in their disease course. With each subsequent line of therapy (LOT), pt outcomes and health-related quality of life (HRQoL) worsen. Pts with MM who are refractory to immunomodulatory drugs, proteasome inhibitors (PIs), and anti-CD38 antibodies (triple-class refractory; TCR) have a poor prognosis and the holistic burden is not well understood. To capture these features, the ongoing prospective Connect ® MM Disease Registry was used to report treatment patterns and outcomes in pts with TCR MM. Methods: Data from September 28, 2009 to February 4, 2021 were used. Eligible pts were ≥18 years of age at first documented diagnosis of MM, which became TCR during their disease course. MM was defined as refractory to therapies based on the International Myeloma Working Group Criteria. Index date was defined as first record of TCR during the disease course. Data analyzed included pt characteristics, treatment patterns pre- and post-index, overall survival (OS), healthcare resource utilization (HCRU), and HRQoL. General HRQoL was captured by EQ-5D-3L utility index (range −0.11-1, higher score indicated better HRQoL), EQ-5D visual analog scale (VAS) score (range 0-100, "worst imaginable" to "best imaginable" health status), and FACT-G total score (range 0-108). Disease-specific HRQoL was measured by FACT-MM total score (range 0-164), FACT-MM Trial Outcome Index (TOI) (range 0-112), and the Brief Pain Inventory (BPI) average pain item (range 0-10, "no pain" to "worst pain you can imagine"). Higher scores indicated better HRQoL for all FACT-related index scores. Cohort-level clinically meaningful change in HRQoL during post-index year 1 was defined as 0.08 for the EQ-5D utility index, 7 for the EQ-5D VAS, and 6-8 points for the FACT-G total score. Validated thresholds were unavailable for other index scores. All statistical analyses were descriptive. Results: This analysis included 240 pts identified from the Registry. Mean age at index date was 68.1 (standard deviation [SD] 10.4) years. Mean time from initial MM diagnosis was 64.1 (SD 26.9) months. 63.3% of pts had prior stem cell transplantation. Mean number of prior LOTs was 4 (SD 1.7). 64.6% of pts had received a subsequent MM LOT since index date. Median follow-up time post-index date was 4.6 months. Treatment pattern analysis of post-index treated pts (Table A) revealed that retreatment with an immunomodulatory drug, PI, or anti-CD38 agent post-index date was common, led by carfilzomib (47.1%) and pomalidomide (40.0%). However, no therapeutic combination was preferred in this pt population. Regarding their index therapy (first post-index LOT), 70.3% and 22.6% were on triplet and quadruplet combination therapy; 3.2% initiated belantamab mafodotin, selinexor, melflufen, and/or idecabtagene vicleucel; mean duration of treatment was 5.6 (SD 6.1) months. For all pts, median OS was 8.9 months; median OS for those who received < 4 prior LOTs (43.8%) versus those who received 4 or more prior LOTs (56.2%) was 10.0 and 8.0 months, respectively. Regarding HCRU during the post-index follow-up, all-cause and MM-related hospitalizations were observed in 49.6% and 23.8% of all eligible pts, respectively. Among these pts, annualized mean number of all-cause/MM-related hospitalization and length of hospital stay were estimated as 8.5 (SD 18.2)/11.0 (SD 25.2) and 64.0 days (SD 80.0)/ 69.2 days (SD 83.7), respectively. Analysis of HRQoL showed a numerical decline in HRQoL relative to index during the 1-year post-index period across all studied HRQoL instruments. There was a clinically meaningful decline in HRQoL from baseline following the index date based on the EQ-5D utility index, EQ-5D VAS, and FACT-G total score (Table B). Conclusion: Pts with TCR MM experienced poor survival, substantial hospitalizations, and a clinically meaningful decline in HRQoL. 35.4% of pts did not receive any new LOTs since the disease became TCR. Among those who did receive subsequent LOTs, re-treatment with an immunomodulatory drug, PI, or anti-CD38 antibody therapy occurred, showing a lack of novel treatment options. This study suggests novel tolerable and efficacious therapeutic agents are needed to address the burden of illness in pts with MM. Figure 1 Figure 1. Disclosures Tang: Bristol-Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Hari: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Celgene-BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Adaptive Biotech: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Karyopharm: Consultancy; GSK: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other, Research Funding, Speakers Bureau; Millenium: Membership on an entity's Board of Directors or advisory committees, Research Funding. Ramasamy: Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene - Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Weisel: Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Consultancy; Novartis: Honoraria; Pfizer: Honoraria. Joshi: Bristol Myers Squibb: Current Employment. Liu: Bristol Myers Squibb: Current Employment. Che: Bristol Myers Squibb: Current Employment. Hernandez: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Abonour: Jensen: Honoraria, Research Funding; Celgene-BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Consultancy, Honoraria, Research Funding; Takeda: Research Funding. Hardin: Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees. Rifkin: Sanofi: Membership on an entity's Board of Directors or advisory committees; McKesson: Current Employment, Current equity holder in publicly-traded company; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Fresenius-Kabi: Membership on an entity's Board of Directors or advisory committees; Coherus: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb (Celgene): Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Ailawadhi: BeiGene, Ltd.: Consultancy; Bristol Myers Squibb: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; Ascentage: Research Funding; Medimmune: Research Funding; Cellectar: Research Funding; Xencor: Research Funding; GSK: Consultancy, Research Funding; Takeda: Consultancy; Genentech: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy; Sanofi: Consultancy; Oncopeptides: Consultancy. Lee: Legend Biotech: Consultancy; Sanofi: Consultancy; Oncopetides: Consultancy; Bristol Myers Squibb: Consultancy; Amgen: Consultancy, Research Funding; Celgene: Consultancy; Janssen: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy, Research Funding; Karyopharm: Consultancy; Regeneron: Research Funding; Genentech: Consultancy; GlaxoSmithKline: Consultancy, Research Funding. Terebelo: Pharmacylics: Speakers Bureau; Celgene-BMS: Consultancy; Takeda: Speakers Bureau; Janssen: Speakers Bureau. Durie: Amgen, Celgene/Bristol-Myers Squibb, Janssen, and Takeda: Consultancy; Amgen: Other: fees from non-CME/CE services . Narang: Bristol Myers Squibb: Consultancy; TG Pharma: Consultancy. Toomey: Bristol Myers Squibb: Consultancy. Gasparetto: Oncopeptide: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy; Sanofi: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria, Speakers Bureau; Gsk: Consultancy, Honoraria, Speakers Bureau. Wagner: Celgene-BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Athenex Inc: Consultancy; Eli Lilly, Johnson & Johnson: Other: Spouse, previously held individual stocks;. Jagannath: Janssen Pharmaceuticals: Consultancy; Bristol Myers Squibb: Consultancy; Karyopharm Therapeutics: Consultancy; Legend Biotech: Consultancy; Sanofi: Consultancy; Takeda: Consultancy.

Abstract Background There has been an increase in overall utilization as well as improvement in overall survival (OS) after hematopoietic cell transplantation (HCT) for most hematologic disorders over time. It is not known if these changes have impacted racial/ethnic minorities equally. In this study, we describe changes in the volume and rate of autologous (auto) and allogeneic (allo) HCT and examine trends in survival in different racial/ethnic groups from 2009 to 2018. Methods Data were obtained from the Center for International Blood and Marrow Transplant Research (CIBMTR) which collects patient data on most autologous and allogeneic HCT recipients in the US. We compared the number of auto and allo transplants in 4 different racial/ethnic groups: Non-Hispanic Whites (NHWs), African Americans (AAs), Hispanics and 'Others' across five 2-year cohorts from 2009 to 2018. 'Others' included Asians, Pacific Islanders and Native Americans as well as non-US residents. Since numbers in individual categories were too low to be meaningful, they were grouped together as 'Others'. Multi race individuals and those with either race or ethnicity missing were excluded. Cox proportional hazards models were used to examine trends in overall mortality after auto HCT in adult patients (for NHL, HD, and MM), and allo HCT among adult and pediatric patients (for AML, ALL, lymphoma including chronic lymphocytic leukemia, and MDS/MPD) in the 4 different racial ethnic groups over 5 study time periods. These models were adjusted for sociodemographic and clinical variables (age, sex, Karnofsky/Lansky score, HCT-comorbidity index, disease, disease status, geographic region, insurance, marital status, education, distance to the transplant center, median income derived from patient's ZIP code). Graft type, donor, conditioning, GVHD prophylaxis, donor-recipient CMV match and donor-recipient sex match were included for allo HCT models. Results A total of 80,080 (59,666 NHWs, 10,683 AAs, 7,110 Hispanics) patients received an auto HCT and 60,412 (44,272 NHWs, 4,964 AAs, 7,826 Hispanics) received an allo HCTs from 2009 to 2018. The volume of auto and allo transplants increased overall, as well as within each race/ethnicity group, over the study periods. In addition, there was a significant change in the proportion of patients in each racial/ethnic group undergoing an auto HCT, with a lower proportion of NHWs and increased proportion of minorities over time (from 78%, 12% and 8% in 2009 -2010 to 71%, 15% and 10% in 2017-2018 for NHWs, AAs and Hispanics respectively; p<0.001). Similar trends were observed for allo HCT: from 76%, 8% and 12% in 2009-2010 to 71%, 9% and 14% in 2017-2018 of all allo HCTs for NHWs, AAs and Hispanics respectively; p<0.001. While there was an increase in the rate of transplants over the years across all racial/ethnic groups, the rate was higher in AAs and Hispanics as compared to NHWs (Table 1). There was no significant difference in overall mortality amongst the three main racial ethnic groups, though there was decrease in mortality over time for auto HCT and adult allo HCT patients. In the allo HCT pediatric group, AAs had higher overall mortality as compared to NHWs across all time periods. (Table 2) Figure 1 shows temporal trends in two-year survival by race and ethnicity. Conclusions This large population-based study shows an improvement in the rates and survival of auto and allo HCT in adults over time. Changes in the proportion of different racial/ethnic groups undergoing HCT are higher than rate of change of population growth (3% decline for NHWs, no change in AAs and 2% increase in Hispanics from 2010 to 2019 per William H. Frey analysis of census population estimates released June 25, 2020). Progress is reflected in higher rates of increase in racial/ ethnic minority groups and comparable survival across the racial ethnic groups in our cohort as compared to two prior registry studies (Baker et al. JCO 2005 and Baker et al. BBMT 2009) for most HCT patients. However, in pediatric patients undergoing allo HCT, the gap in survival between NHWs and AAs has continued to persist over the years. With increasing diversity of the US population, we need to strengthen our efforts for improving access to, and outcomes of HCT to narrow the gap for all patients requiring HCT, irrespective of their sociodemographic characteristics. Figure 1 Figure 1. Disclosures Wood: Koneksa Health: Consultancy, Current equity holder in publicly-traded company; Teladoc: Consultancy; Pfizer: Research Funding. 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. Saber: Govt. COI: Other.

Abstract Background: trALL is an important secondary primary malignancy (SPM) that has recently been appreciated. While patients (pts) with MM have an 8%-17% risk of developing an SPM while on lenalidomide (R) maintenance following autologous stem cell transplant (ASCT), trALL has been rarely observed. Little is known about the characteristics of trALL in pts with MM compared to pts who had other malignancies prior to the development of trALL. We define tALL as any prior exposure to cytotoxic chemotherapy and/or radiation for another malignancy, and herein, we report a comparative analysis of characteristics and outcomes of pts with trALL with and without MM from the Mayo Clinic Cancer Center (MCCC). Methods: We performed a systematic search in the 3-site MCCC registry and included all pts diagnosed and received at least 1 cycle of ALL-directed therapy and/or underwent allogeneic transplantation (AlloHCT) for ALL between 2007-2020. All cases of trALL in this series are B-ALL. Comparisons of characteristics between trALL patients with and without MM were made using a Wilcoxon rank sum test (continuous variables) or Fisher's exact test (categorical variables). Time-to-event variables were compared using unadjusted Cox proportional hazards regression models. Results: 70 trALL pts (14 MM [20%], 56 non-MM [80%]) were identified during the study period. The median age at trALL diagnosis was 63.9 (range 47-71) for MM pts and 63.1 (range 18.2-84) for non-MM pts. Median follow-up from trALL diagnosis was 1.42 years (range 0.02-10.6 years). The most common prior non-MM malignancies among tALL pts were breast (28.6%), lymphoma (17.9%), myeloid (17.9%), and GU/GYN (14.3%). Amongst the 14 MM pts, 100% (n=10) had ISS-I disease, 8 (57%) had IgG K MM, 1 (n=10) had high risk cytogenetics, 8 (57.1%) received R-based induction , 4 (28.6%) received CyBorD induction, 4(28.6%) received VRD induction, 3 (21.4%) received RD induction. 10 (71.4%) pts were actively on R when they developed trALL, 8 (57.1%) pts received prior ASCT. The median time to develop trALL following ASCT for MM was 46.3 months (m), (95% CI 20.4-67.6), 12 (85.7%) pts received R maintenance with a median duration of 53m (95% CI 16.9-121). The median time to develop trALL after initiation of R maintenance was 61.2m (95% CI 16.9-123.4). The most common trALL induction regimen received was HyperCVAD which was used in 71.4% of MM pts and 51.8% of non-MM pts. In comparison to non-MM pts, MM patients had a significantly lower WBC at diagnosis (Median: 2.0 vs. 5.8, P=0.005),no t(9;22) BCR/ABL1 cytogenetics (0.0% vs. 35.7%, P=0.008), a higher frequency of hypodiploid/near-triploid (Ho-Tri) cytogenetics (42.9% vs. 12.5%, P=0.009), and a lower frequency of prior radiation therapy (7.1% vs. 44.6%, P=0.012). MM pts had a higher frequency of AlloHCT for trALL (71.4% vs. 42.9%, P=0.075) and were more commonly in complete response (CR) at transplant (100.0% vs. 70.8%, P=0.078). No trALL in MM pts were Ph-like ALL. There was a statistically significant difference in time to development of trALL between previous malignancy locations (P=0.018), with GU/GYN (Median: 9 years) having the longest time and myeloid (Median: 3 years) having the shortest time; MM was 6 years. In the overall pt cohort, 56 (80%) pts achieved a complete response after induction and 60% (n=25) were minimal residual disease (MRD)+ after induction. Pts with MM had a significantly lower likelihood of being MRD+ after induction (OR=0.09, P=0.015). Overall, 24.3% of pts relapsed after induction therapy for trALL; 39 (55.5%) died after trALL diagnosis including 43% (n=35) who died after AlloHCT. Although pts with MM tended to have better outcomes compared to non-MM trALL pts in terms of overall survival after trALL diagnosis (Figure 1A), survival after AlloHCT (Figure 1B), relapse rate after trALL diagnosis and non-relapse mortality after AlloHCT, none of these findings were statistically significant in this small cohort (Figure 1C). Conclusion: trALL is a unique SPM that can occur in pts with MM. It is associated with Ho-Tri cytogenetics and is BCR/ABL1 negative. The majority of MM pts that developed trALL had undergone prior ASCT and were on R maintenance when they developed trALL. Despite being more likely to have adverse cytogenetics features, MM-associated trALL has similar survival compared to non-MM-associated trALL which speaks to the poor survival outcomes of this SPM. Further research on trALL in MM pts is merited. Figure 1 Figure 1. Disclosures Litzow: Amgen: Research Funding; Pluristem: Research Funding; AbbVie: Research Funding; Actinium: Research Funding; Astellas: Research Funding; Omeros: Other: Advisory Board; Jazz: Other: Advisory Board; Biosight: Other: Data monitoring committee. Bergsagel: Janssen: Consultancy. Fonseca: Scientific Advisory Board: Adaptive Biotechnologies: Membership on an entity's Board of Directors or advisory committees; Caris Life Sciences: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy; Patent: Prognosticaton of myeloma via FISH: Patents & Royalties; Bayer: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Amgen: Consultancy; BMS: Consultancy; Mayo Clinic in Arizona: Current Employment; Juno: Consultancy; Kite: Consultancy; Aduro: Consultancy; OncoTracker: Consultancy, Membership on an entity's Board of Directors or advisory committees; GSK: Consultancy; Novartis: Consultancy; Merck: Consultancy; Sanofi: Consultancy; Pharmacyclics: Consultancy; Janssen: Consultancy. Dispenzieri: Takeda: Research Funding; Alnylam: Research Funding; Pfizer: Research Funding; Oncopeptides: Consultancy; Sorrento Therapeutics: Consultancy; Janssen: Consultancy, Research Funding. Murthy: CRISPR Therapeutics: Research Funding. Ailawadhi: GSK: Consultancy, Research Funding; Sanofi: Consultancy; Pharmacyclics: Consultancy, Research Funding; Takeda: Consultancy; Medimmune: Research Funding; Xencor: Research Funding; Genentech: Consultancy; Janssen: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Cellectar: Research Funding; Beigene: Consultancy; BMS: Consultancy, Research Funding; AbbVie: Consultancy; Karyopharm: Consultancy; Ascentage: Research Funding. Foran: actinium: Research Funding; taiho: Honoraria; bms: Honoraria; servier: Honoraria; pfizer: Honoraria; novartis: Honoraria; OncLive: Honoraria; abbvie: Research Funding; boehringer ingelheim: Research Funding; takeda: Research Funding; trillium: Research Funding; aptose: Research Funding; revolution medicine: Honoraria; syros: Honoraria; sanofi aventis: Honoraria; certara: Honoraria; gamida: Honoraria; kura: Research Funding; h3bioscience: Research Funding; aprea: Research Funding; sellas: Research Funding; stemline: Research Funding.

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.