Citations

Abstract The treatment landscape for relapsed multiple myeloma (MM) has increased. In this study we aimed to characterize 2nd (n = 1439) and 3rd (n = 1104) line regimens and compare the results between subgroups based on the year of treatment initiation (2nd line: 2003–2008, 2009–2015, 2016–2021; 3rd line: 2004–2009, 2010–2015, and 2016–2021). In both 2nd and 3rd line we observed increasing use of novel agents (from 78–95% and from 77–95%, respectively) and triplet regimens (from 15–69% and from 21–71%, respectively). Most frequently used regimens in the last studied periods included lenalidomide-dexamethasone (RD; 14%), carfilzomib-RD (12%) and daratumumab-RD (10%) for 2nd line, and daratumumab-pomalidomide-dexamethasone (11%) and daratumumab-RD (10%) for 3rd line. Median time to next treatment from 2nd line therapy has improved from 10.4 months (95% CI 8.4–12.4) to 16.6 months (95% CI 13.3–20.3; p < 0.001). The median overall survival from 1st relapse increased from 30.9 months (95% CI 26.8–183.0) to 65.8 months (95% CI 50.7–72.8; p < 0.001). Over the last two decades more patients were treated with newer agents and triplets for relapsed MM. The landscape of regimens has become more diverse, and the survival after 1st relapse is continually improving.

Abstract Bortezomib, a proteasome inhibitor (PI), has shown efficacy in the treatment of newly diagnosed and relapsed light chain (AL) amyloidosis, and is often used in combination with cyclophosphamide and dexamethasone. Ixazomib is the first oral PI to be approved in routine practice but has not yet been evaluated in the upfront treatment setting. Newly diagnosed AL amyloidosis patients with measurable disease and adequate organ function were enrolled. The primary objective was to determine the hematologic response rate of ixazomib in combination with cyclophosphamide and dexamethasone. Treatment was given for 12 cycles, followed by ixazomib maintenance until progression. Thirty-five patients were included; their median age was 67 years, and 69% were male. Major organ involvement included heart (66%) and kidneys (54%). A median of 4 induction cycles (range, 1-12) were administered. The overall hematologic response to induction was 63% and included complete response in 11.4% and very good partial response in 37.1% of patients. One patient was upstaged to complete response during maintenance. The most common reason for going off study was the institution of alternate therapy (61%). With a median follow-up of 29.7 months for the living patients, the 2-year progression-free survival and overall survival were 74% and 78%, respectively. The median time to alternate therapy was 7.5 months. Grade ≥3 hematologic and nonhematologic adverse events occurred in 23% and 49% of patients. Given ixazomib’s favorable toxicity profile, which is an important advantage for the typically frail AL population, further evaluation of ixazomib in other combinations in the upfront setting is warranted. This trial was registered at www.clinicaltrials.gov as #NCT01864018.

SummaryBelantamab mafodotin (BLMF) is a B‐cell maturation antigen‐directed antibody‐drug conjugate, recently approved for advanced multiple myeloma (MM). The impact of BLMF‐induced ocular toxicity on patient outcomes is unknown. We studied a cohort of 38 consecutively seen patients treated with BLMF outside of trials. Of those, 75% experienced ocular toxicity, with 69% developing keratopathy. Among patients requiring ocular toxicity‐related permanent BLMF discontinuation (14%) or dose reduction (11%), 70% had progression of MM within a median of 3 months (95% confidence interval: 0.2–not reached) following BLMF interruption or dose reduction. Ocular toxicity is a major deterrent to the continuous use of BLMF in routine clinical practice. Measures to successfully prevent and mitigate ocular toxicity should be developed to achieve the full potential of this agent.

8022 Background: Bone marrow (BM) assessment of minimal residual disease (MRD) is being considered as a surrogate endpoint in clinical trials and is prognostic for survival in multiple myeloma (MM). Timing of BM assessment is variable across Chimeric Antigen Receptor T cell (CART) therapy trials and differs from standard of care practice. BM myeloma cell clearance can be detected by month 1 post CART, even before serum immunofixation becomes negative. BM is still hypocellular at month 1, thus prognostic value of MRD negative (MRDneg) at this timepoint is unclear. We examined impact of Day 30 MRD status in patients (pts) who received CART at Mayo Clinic. Methods: Medical records were reviewed retrospectively for MM pts who received CART between 8/2016 and 6/2021. PFS and OS were plotted by Kaplan-Meier method. Results: Sixty MM pts received CART and had BM biopsy at month 1. Median age was 62 yrs, 53% were male, and 78% were BM MRDneg by flow cytometry. Baseline demographics were similar between MRDneg and MRD+ (Table). Overall, 85% (40/47) who were month 1 BM MRDneg had i/u FLC<normal. Patients who achieved CR/sCR had higher rates of BM MRDneg (100% vs 61%, p<0.001) and i/u FLC< normal (89% vs 58%, p<0.001). At month 1, 24/60 (40%) pts had hypocellular BM. Serial BM samples at month 3 (n=35), 6 (n=28) and 12 (n=23) showed MRDneg rate of 93% (25/27), 56% (9/16) 58% (7/12), respectively.. Rate of hypocellularity was 54% (19/35), 32% (9/28) and 30% (7/23), respectively. Among the MRDneg/hypocellular pts at month 1, hypocellular BM was seen in 8/11 (73%) pts at month 3 and 2/4 (50%) pts at month 6 and 12. Compared to MRD+, pts who had BM MRDneg at months1 had longer PFS (Table). PFS was not statistically significantly different between pts who had BM MRDneg and were either hypocellular or not. MRDneg pts with i/u FLC<normal at months1 had better median PFS compared to those who did not. (MRD+:2.9 months (1.2-NR). MRDneg/FLC>normal: 4.9 months (2.3-NR). vs MRDneg/FLC<normal:17.9 months (11.8-NR), p<0.0001). Conclusions: Hypocellular BM is common in the 3 months post CART. Regardless of BM cellularity, BM MRDneg at month 1 correlates with deep response and prolonged PFS. Majority of BM MRDneg pts at month 1 also had FLC<normal. BM MRDneg status and FLC normalization were associated with longer survival. Our data support the continued evaluation of BM early post CART infusion as a prognostic tool. [Table: see text]

e20001 Background: High dose melphalan followed by autologous stem cell transplant (HDM-ASCT) remains the standard of care for transplant-eligible patients with newly diagnosed multiple myeloma (NDMM) despite advances in treatments. Achievement of complete response (CR) is associated with improved overall survival (OS) and progression-free survival (PFS); Minimal Residual Disease (MRD) negativity (-) using next generation flow cytometry with a sensitivity of 10-5 is strongly associated with improved PFS and OS. We investigated the rates of conversion to MRD(-), especially MRD(-) CR following HDM-ASCT in patients with NDMM. Methods: We retrospectively reviewed patients with NDMM who underwent early HDM-ASCT at Mayo Clinic Rochester from May 2018 to July 2019. Response assessment was conducted after induction and within 100 days post-ASCT based on 2016 IMWG criteria, except for using Mass-Fix instead of immunofixation. MRD was assessed in bone marrow using the established Euro Flow protocol with sensitivity of 10-5. The FISH assay was used to risk-stratify patients as high-risk (HR) and standard risk (SR) cytogenetics as per the mSMART guidelines. Primary outcome measure was the conversion to MRD(-) CR after ASCT. Secondary outcomes include the overall conversion to MRD(-) irrespective of IMWG response, the impact of HR cytogenetics and pre-ASCT IMWG response on conversion to MRD(-) CR. Results: Two-hundred and ten patients were included; 126 (60%) were male and median age 62 years (range 32–77 years). There were 78 (44%) patients with HR cytogenetics. Pre-ASCT, 23 patients (11%) achieved MRD(-) CR, and 66 (31%) patients achieved MRD(-) CR post ASCT. Of 187 patients not in MRD(-) CR pre-ASCT, 45 (24%) converted to MRD(-) CR. Table provides a breakdown of the conversion rate of pre-ASCT IMWG response category to MRD(-) CR post ASCT and patients with MRD(+) CR had the highest rate (78%) of conversion. The presence of HR cytogenetics did not impact rates of MRD(-) CR achievement post ASCT irrespective of pre-ASCT IMWG response (p = 1.0). Overall, irrespective of IMWG response, 43 (20%) patients were MRD(-) pre-ASCT (19 in VGPR, 24 in CR or better) and 102 (49%) patients were MRD(-) post-ASCT (36 in VGPR, 66 in CR or better). Among 85 patients in VGPR post-ASCT, 36 were MRD(-) of which 8 (22%) progressed, while 49 were MRD(+) of which 24 (49%) progressed (p = 0.014). Conclusions: Upfront HDM-ASCT in patients with NDMM leads to deeper responses with 24% converting to MRD(-) CR and more than doubling of the total rate of MRD(-) irrespective of IMWG response. [Table: see text]

e18544 Background: Underrepresented minority (URM) patients continue to make up a small percentage of patients treated on cancer clinical trials (CCTs), thus perpetuating health care disparities. Research indicates that engagement of healthcare staff is critical for successful recruitment. Our study sought to better define barriers to minority recruitment to CCT from the research staff perspective. Methods: Semi-structured qualitative interviews were conducted of key stakeholders for CCT enrollment, including clinical research coordinators (CRCs), principal investigators (PIs), and treating clinicians. Questions for the healthcare team explored their experiences caring for URM patients with specific inquiry into the barriers of enrollment/retention and the processes or resources required to better meet patient needs. Results: All hematology and oncology staff at Mayo Clinic Cancer Center were invited to participate via email. Of the 28 who consented, 13 were male (46%), 15 female (54%), and 21% non-white (3 Asian, 2 Hispanic, 1 Black). Of the 19 PIs, 9 were Professors (47%), 5 Associate professors (26%), and 5 Assistant professors (26%). The additional 9 interviewees were CRCs. Select themes with representative quotes and proposed actions can be seen in Table. Conclusions: Recommendations for CCT accrual include accelerating efforts to address workforce diversity gaps, engaging in community outreach, optimization of CCT participation through collaborative care, incentivizing trial participation, and creating flexibility in eligibility criteria.[Table: see text]

e18543 Background: Representation of minority patients (pts) in cancer clinical trials (CCTs) is low and contributes to health disparities. Our study sought to understand the beliefs and motivations of minority patients and to identify barriers and facilitators of CCT enrollment. Methods: 270 minority pts treated on CCT were identified from the medical record from 2018-2021. Of the 138 of pts alive, 13 (9.4%) consented. Semi-structured qualitative interviews were conducted exploring motivations, barriers, and facilitators to CCT participation. Surveys collected demographics and explored beliefs towards cancer and factors that influenced participation. Results: Of the 13 participants, 9 were female (69%), 4 Hispanic (30%), 3 Black (23%), 3 multiple races (23%), 2 Asian (15%), 2 Native American (15%), and 1 Native Hawaiian (8%). Two pts had a high school education (15%), 7 ≥ 4-year college (54%), 4 ≥ 2-year college (30%). Eight pts were married, 3 divorced, 1 widowed, and 1 single. Employment status was: employed (4 pts, 30%), unemployed (1 pt, 8%), disabled (5 pts, 38%), retired (3 pts, 23%). All pts were insured. Median household was 3 people (range 1 to > 5); 3 pts had dependents. 9 pts had their own vehicle; 4 used public or subsidized transport. 2 pts had trouble finding transportation. Income was: 3 pts < 25K, 4 pts 25-35K, 1 pts 35-50 K, 1 pts 50-75K, and 4 pts > 75K. 4 pts received emotional support from religion. All pts had heard of CCTs and 6 (46%) had known other CT participants. Direct communication from healthcare provider was the most common way of hearing about CCT. 9 pts (69%) had trust or strong trust in experimental therapy/CCT; 4 pts (30%) were neutral. 8 pts (61%) believed standard therapy was needed to cure cancer. 5 pts (38%) believed God would decide if they die from cancer. 7 pts (54%) believed that worry makes cancer worse. Key themes about patients’ motivation to participate: chance for cure, staying positive, giving back to others, having representation in research, and advancing science. Key themes about facilitators to participation: supportive family, cost coverage for treatment, and limited treatment options. Key themes on participation: minimizing logistical barriers, decentralizing CCTs, increasing awareness via patient narratives, diversifying research staff, minimizing cost, and being clear on purpose and benefit of CCT. Factors from survey that influenced participation are summarized in Table. Conclusions: Understanding minority pts experience through in-depth interviews is valuable and may help with recruitment.[Table: see text]

110 Background: Sarcopenia or a loss of muscle mass increases with aging and is associated with increased overall mortality in patients with cancer. Recent advances in machine learning–based CNN algorithms have allowed for the rapid processing of digital images to produce image classifications of body composition. Since incidence of MM is highly associated with aging, we sought to determine if the presence of sarcopenia, as determined by utilizing this machine learning–based CNN algorithm on CT images, had prognostic value in patients with NDMM. Methods: We identified all patients with NDMM from January 2003 to July 2019 who had a standard-dose CT scan that included the L3 vertebral level performed within 6 months of diagnosis. Using a machine learning–based CNN-algorithm, abdominal CT images were analyzed to measure muscle area. These measurements were normalized by dividing the area values by the height of the patient squared (m2) to obtain skeletal muscle index (SMI) values. Patients were categorized as sarcopenic according to international gender-specific consensus cutoffs for SMI (male: < 55 cm2/m2 and female: < 39 cm2/m2). Patients with the following FISH cytogenetics were considered high risk (HR): t(4;14), t(14;16), t(14;20), and deletion 17p/monosomy 17 whereas the remainder were standard risk (SR). Survival analysis was performed using the Kaplan-Meier method and compared via the log-rank method. Results: The study cohort consisted of 344 patients. 68 (20%) were categorized as HR based on FISH cytogenetics.187 (54%) patients were sarcopenic based on their peri-diagnosis standard-dose CT scan. Sarcopenic patients were more likely to have ISS-3 disease (45% vs. 30%; p =.023), be male (73% vs. 48%; p <.001), and be ≥ age 75 (27% vs. 14%; p =.002) compared to non-sarcopenic patients. The median OS for patients with HR FISH and ISS 2 / 3 disease was 40 months and 57 months respectively compared to 90 months and 119 months for those with SR FISH and ISS-1 disease respectively (FISH: p <.004; ISS: p <.001). The median OS for sarcopenic patients was 44 months compared to 90 months for those not sarcopenic (p <.001). The time to next therapy (TTNT) for sarcopenic patients was 39 months compared to 45 months for those not sarcopenic (p =.05). In a multivariable model, the presence of sarcopenia (HR 1.64, 95% CI, 1.05–2.56; p =.03) retained significance in the presence of HR FISH, ISS 2 / 3 disease, and age ≥ 75. Conclusions: Gender-specific sarcopenia identified by a machine learning–based CNN algorithm significantly affects OS in patients with NDMM and is independent of age, ISS stage, and cytogenetic status. Future studies utilizing this machine learning–based methodology of assessing sarcopenia in larger prospective clinical trials are required to validate these findings.