Citations

Background: PT-112 is a novel pyrophosphate-platinum conjugate with a multi-modal mechanism of action that induces immunogenic cell death and is not susceptible to DNA-repair drug resistance pathways. In phase I studies in solid tumors, PT-112 demonstrated safety and efficacy as single agent and in combination with PD-L1 checkpoint inhibitor avelumab, crossing a range of dose levels (DL) and tumor types, including in heavily pre-treated patients (pts) non-responsive to immunotherapy and refractory to other modalities. Non-clinical, in vivo research using advanced imaging technology demonstrated that PT-112 reached the highest concentrations in bone tissue (osteotropism). Moreover, PT-112 was highly active in the orthotopic, immune-competent Vk*MYC mouse model of multiple myeloma, including drug-resistant transplant variants. Thus, a rationale for PT-112 as an investigational candidate in multiple myeloma was established. Here, we present results of a phase I dose escalation study of PT-112 in pts with relapsed or refractory multiple myeloma (RRMM). Methods: A 3+3 design was used to determine the recommended phase 2 dose (RP2D) for PT-112 (28-day cycle IV days 1, 8, 15) in pts with evaluable RRMM who had exhausted available therapies (Tx), with adequate bone marrow (abs neutrophil count ≥ 1.0 x 109/L; platelet count ≥ 50 x 109/L; and hemoglobin ≥ 8.0 g/dL) and renal function (calculated creatinine clearance ≥ 30 mL/min), and ECOG PS 0-2. Results: A total of 24 pts were treated with PT-112 monotherapy across 6 DLs: 125 mg/m2, 3 pts; 180 mg/m2, 4 pts; 250 mg/m2, 5 pts; 300 mg/m2, 4 pts; 360 mg/m2, 4 pts; 420 mg/m2, 4 pts. Patients had a median age of 72 years and were heavily pre-treated, with a median of 8 prior lines of systemic Tx: 22 (92%) pts were triple-class refractory with 19 (79%) pts penta-refractory, and 3 (13%) pts refractory to BCMA-based therapies. The most common treatment-related adverse events (TRAEs) were thrombocytopenia (58%), neutropenia (42%), diarrhea (38%), and nausea (38%). 38% of pts had ≥1 grade 3 non-hematologic TRAE, with no grade 4 non-hematologic TRAEs reported. One dose-limiting toxicity (DLT) of grade 4 neutropenia occurred at the 420 mg/m2 DL. In addition, due to frequent dose reductions and modifications at this DL, the safety committee declared 360 mg/m2 as the RP2D. Among 8 patients who received a starting dose at / above the RP2D, 2 had stable disease and 4 experienced responses to PT-112 Tx. These included a confirmed partial response (PR) achieved in a 79-year-old pt with kappa free light chain (FLC) disease treated at 360 mg/m2, whose previous Tx included combination regimens with most approved therapies (penta-refractory) and stem cell transplantation. FLC levels declined by 65% from baseline on PT-112 therapy and the pt remained progression free for 4.5 months. A 72-year-old pt treated at the 420 mg/m2 DL, reduced to 250mg/m2 every other week over the course of Tx due to grade 3-4 cytopenias, had a confirmed minor response. Prior Tx with multiple lines given over 9 years included stem cell transplantation, most approved therapies (penta-refractory), prior investigational antibody and CAR-T cell Tx (primary refractory to CAR-T). The patient was M-protein negative, kappa FLC levels declined by 32% following the first dose reduction, and the pt remained progression free and clinically stable without complaints for 4.5 months. Additionally, two transient, unconfirmed PRs occurred in patients at the 420mg/m2 DL: in a triple-class-refractory 82-year-old previously treated with 5 lines of Tx, with 70% reduction in kappa FLC during cycle 1; and in a penta-refractory 85-year-old, who experienced disappearance of M-protein during cycle 1 and Gr 4 neutropenia (DLT). Conclusions: PT-112 monotherapy was feasible and well tolerated in this heavily pre-treated, multi-refractory multiple myeloma population, and the Phase I clinical data appear to validate the developmental hypothesis, built upon activity in the Vk*MYC mouse model of multiple myeloma. Responses were confirmed in 25% of patients treated at / above the RP2D using single-agent PT-112, an encouraging result in a dose escalation trial conducted in heavily refractory patients. Activity of PT-112 in RRMM patients may be explained by its osteotropism and its unique mechanism of action compared to other drug classes used to treat this disease. Further clinical study of PT-112 in RRMM is warranted in a phase 2 clinical trial. Disclosures Ailawadhi: Celgene: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Amgen: Research Funding; Medimmune: Research Funding; BMS: Research Funding; Cellectar: Research Funding; Phosplatin: Research Funding; Takeda: Honoraria. Vogl:Janssen: Consultancy; Celgene: Consultancy; MorphoSys: Consultancy; Takeda: Consultancy; Active Biotech: Consultancy, Research Funding; Oncopeptides: Consultancy; Karyopharm: Consultancy. Ames:Phosplatin Therapeutics: Current Employment, Current equity holder in private company. Yim:Phosplatin Therapeutics: Current Employment, Current equity holder in private company. Price:Phosplatin Therapeutics: Current Employment, Current equity holder in private company. Jimeno:Phosplatin Therapeutics: Current Employment, Current equity holder in private company.

SummaryAlthough new multiple myeloma (MM) therapies are effective in alleviating some disease‐associated symptoms (e.g. bone pain, fatigue, functional decline), they can result in additional toxicities, further impacting health‐related quality of life (HRQoL). Here, we compared HRQoL and safety of lenalidomide‐bortezomib‐dexamethasone [RVd (n = 445)], bortezomib‐melphalan‐prednisone [VMP (n = 77)] and Vd or VMP (n = 588) in patients with newly diagnosed MM (NDMM) from the Connect® MM Registry, a large, USA, multicentre, prospective observational cohort study. Functional Assessment of Cancer Therapy‐Multiple Myeloma subscale, EuroQol‐5D overall score and Bone Pain Inventory HRQoL scores were significantly improved with RVd versus Vd/VMP. Serious adverse event rates were similar in all groups. Treatment with RVd maintained HRQoL in this real‐world, largely community‐based population of patients with NDMM.

230 Background: Inpatient mortality review is commonly used to improve patient care. Individual review of outpatient deaths is less common, yet 30-day mortality after hospital stay is an important quality metric. In this study, we sought to identify opportunities for care improvement by reviewing outpatient mortalities for cancer patients who died within 30 days of hospitalization. Methods: We identified 48 patients at Mayo Clinic Florida, with a hematologic (heme) or solid tumor (onc) cancer, who died within 30 days of an index hospital stay in 2018. We created a 32-question review survey to address quality of care around the hospital stay. The review team consisted of 1) heme or onc attendings, 2) heme/onc fellows, and 3) palliative care attendings. Each case was reviewed by one member of each of the 3 groups, split into heme or onc cases. Discrepancies in objective data points were resolved by the research team. Results: Of 143 surveys sent to 13 physicians (3 heme), 112 responses from 11 physicians (1 heme) for 47 patients were received. Twenty-one patients (45%) received cancer therapy within 30 days of death, and 23 (49%) were admitted >2 times in 2 months prior to death. For onc cases, attendings rated prognosis as discussed 83% of the time, vs 65% of fellows and 39% of palliative care; in heme cases, the attending rated prognosis as discussed 11% of the time, vs 86% of fellows and 50% of palliative care. In heme cases, the attending rated expected survival <3 months in 33% of cases vs 71% by fellows and 89% by palliative care; in onc cases, the reviews were more consistent (79% attending, 85% fellow, 93% palliative care). See Table for timing of prognosis discussions and palliative care involvement. Conclusions: The most common improvement opportunities identified by reviewing heme/onc patients who died within 30 days of a hospital stay included documented prognosis discussion and involvement of palliative care. Opportunities differed between heme and onc patients. Future directions include identifying and mitigating barriers that providers face in reaching these goals for their patients. [Table: see text]

Abstract Background: Persons of African ancestry (AA) experience a 1.5-2-fold risk of multiple myeloma (MM) compared to persons of European ancestry (EA). We assembled a set of MM patients with self-reported AA in order to evaluate the contribution of genetics to etiology in this high-risk group. Methods: Here we present the results of a meta-analysis of two GWAS in 1,813 cases and 8,871 controls of AA. We also conducted an admixture mapping scan to identify risk alleles associated with local ancestry, fine-mapped the 23 known susceptibility loci to find markers that could better capture MM risk in individuals of AA, and constructed a polygenic risk score (PRS) to assess the aggregated effect of known MM risk alleles. Finally, we conducted an eQTL analysis measuring gene expression in those genes harboring a risk variant in malignant plasma cells from 292 of the patients from a single site. Results: In GWAS analysis, we identified two suggestive novel loci located at 9p24.3 and 9p13.1 at P&lt;1 × 10-6, but no genome-wide significant association was noted. In admixture mapping, we observed a genome-wide significant inverse association between local AA at 2p24.1-23.1 and MM risk in AA individuals. 20 of the 23 known EA risk variants showed directional consistency and 9 replicated at P&lt;0.05 in AA individuals. In eight regions, we identified markers that better capture MM risk in persons of AA. AA individuals with a PRS in the top 10% had a 1.82-fold (95%CI: 1.56, 2.11) increased MM risk compared to those with average risk (25-75%). The strongest functional association was between the risk allele for variant rs56219066 at 5q15 and lower ELL2 expression (P= 5.1 × 10–12). Conclusion: Our study shows that common genetic variation contributes to MM risk individuals of AA. This abstract is also being presented as Poster C040. Citation Format: Zhaohui Du, Niels Weinhold, Gregory Chi Song, Kristen A. Rand, David J. Van Den Berg, Amie E. Hwang, Xin Sheng, Victor Hom, Sikander Ailawadhi, Ajay K. Nooka, Seema Singhal, Karen Pawlish, Edward Peters, Cathryn Bock, Ann Mohrbacher, Alexander Stram, Sonja I. Berndt, William J. Blot, Graham Casey, Victoria L. Stevens, Rick Kittles, Phyllis J. Goodman, W. Ryan Diver, Anselm Hennis, Barbara Nemesure, Eric A. Klein, Benjamin A. Rybicki, Janet L. Stanford, John S. Witte, Lisa Signorello, Esther M. John, Leslie Bernstein, Antoinette Stroup, Owen W. Stephens, Maurizio Zangari, Frits Van Rhee, Andrew Olshan, Wei Zheng, Jennifer J. Hu, Regina Ziegler, Sarah J. Nyante, Sue Ann Ingles, Michael Press, John David Carpten, Stephen Chanock, Jayesh Mehta, Graham A Colditz, Jeffrey Wolf, Thomas G. Martin, Michael Tomasson, Mark A. Fiala, Howard Terebelo, Nalini Janakiraman, Laurence Kolonel, Kenneth C. Anderson, Loic Le Marchand, Daniel Auclair, Brian C.-H. Chiu, Elad Ziv, Daniel Stram, Ravi Vij, Leon Bernal-Mizrachi, Gareth J. Morgan, Jeffrey A. Zonder, Carol Ann Huff, Sagar Lonial, Robert Z. Orlowski, David V. Conti, Christopher A. Haiman, Wendy Cozen. A meta-analysis of genome-wide association study and eQTL analysis of multiple myeloma among African Americans [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr PR05.

BackgroundStudies have reported racial disparities in access to and use of multiple myeloma (MM) treatments between African American (AA) and White patients. Although AA patients demonstrate longer disease‐specific survival, this has not uniformly translated into improved survival over time. The association between race and treatment patterns and survival outcomes was analyzed using data from the Connect MM Registry.MethodsThe Connect MM Registry is a large US, multicenter, prospective observational cohort study of patients with newly diagnosed MM. Patients who received first‐line (1L) stem cell transplantation (SCT) or who did not receive SCT (non‐SCT or non–stem cell transplantation [NSCT]) were grouped by raceEffects of race and transplantation status on the use of triplet treatment were estimated using logistic regression.ResultsTreatment patterns in 1L (types and duration of induction, posttransplantation maintenance) were similar between AA and White patients. SCT rates in 1L (32% vs 36%) and triplet treatment use (AA: 44% for NSCT patients and 72% for SCT patients; and White: 48% for NSCT patients and 72% for SCT patients) during first induction were similar. No significant effect of race or transplantation status on 1L triplet treatment use was observed. Race was not found to be associated with survival outcomes among patients who underwent NSCT; however, AA patients who received SCT had significantly longer overall survival compared with White patients who underwent SCT (not reached vs 88.2 months; hazard ratio, 0.56; 95% CI, 0.35‐0.89 [P = .0141]).ConclusionsAA and White patients were found to have similar treatment patterns in the Connect MM Registry, suggesting that both groups had equal access to health care. In this real‐world setting, AA patients received standard‐of‐care treatment, which might have contributed to better MM‐specific survival compared with White patients.

Purpose: Multiple myeloma (MM) treatment has changed tremendously, with significant improvement in patient out-comes. One group with a suboptimal benefit is patients with high-risk cytogenetics, as tested by conventional karyotyping or fluorescence in situ hybridization (FISH). Methodology for these tests has been published, but not necessarily standardized. Methods: We address variability in the testing and reporting methodology for MM cytogenetics in the United States using the ongoing African American Multiple Myeloma Study (AAMMS). We evaluated clinical and cytogenetic data from 1,221 patients (1,161 with conventional karyotyping and 976 with FISH) tested between 1998 and 2016 across 58 laboratories nationwide. Results: Interlab and intralab variability was noted for the number of cells analyzed for karyotyping, with a significantly higher number of cells analyzed in patients in whom cytogenetics were normal (P 5.0025). For FISH testing, CD138-positive cell enrichment was used in 29.7% of patients and no enrichment in 50% of patients, whereas the remainder had unknown status. A significantly smaller number of cells was analyzed for patients in which CD138 cell enrichment was used compared with those without such enrichment (median, 50 v 200; P, .0001). A median of 7 loci probes (range, 1-16) were used for FISH testing across all laboratories, with variability in the loci probed even within a given laboratory. Chromosome 13–related abnormalities were the most frequently tested abnormality (n5956; 97.9%), and t(14;16) was the least frequently tested abnormality (n 5 119; 12.2%). Conclusions: We report significant variability in cytogenetic testing across the United States for MM, potentially leading to variability in risk stratification, with possible clinical implications and personalized treatment approaches.

8518 Background: Patients (pts) with newly diagnosed multiple myeloma (NDMM) and renal impairment (RI) are often excluded from clinical trials. Data are limited on the effects of induction treatment in these pts, who may also be ineligible for autologous stem cell transplant (SCT) due to severity of RI. This analysis investigated the impact of RVd induction on renal function in transplant eligible (TE) and noneligible (TNE) pts from the Connect MM Registry, a US, multicenter, prospective, observational study. Methods: Eligible pts were ≥ 18 y and had symptomatic MM diagnosed ≤ 2 mos prior to enrollment, as defined by the International Myeloma Working Group criteria. For this analysis, pts that received front-line RVd for ≥ 3 cycles were grouped per transplant eligibility and renal function at baseline (BL; creatinine clearance [CrCl] < 30, 30-50, > 50-80, and > 80). Pts with progressive disease at BL were excluded. Renal function at 3 mos was measured. Median unadjusted progression-free survival (PFS) was calculated from start of regimen in TE and TNE populations, with pts grouped by CrCl (≤ 60 or > 60) at BL. Results: As of 7/23/19, 421 TE and 212 TNE pts received RVd for ≥ 3 cycles. TE and TNE pts were grouped by BL CrCl of < 30 (20 and 16 pts), 30-50 (36 and 50 pts), > 50-80 (117 and 63 pts), and > 80 (248 and 83 pts). Renal function improvement was observed in all pts receiving RVd, including those with moderate (30-50 CrCl) and severe (< 30 CrCl) RI at BL (Table). In pts with > 60 CrCl and ≤ 60 CrCl at BL, median PFS in TE pts was 48.6 mos and 43.2 mos, respectively. In TNE pts, median PFS was 36.4 mos and 30.6 mos, respectively. Conclusions: The results from the Connect MM Registry indicate that pts with NDMM and RI (including moderate and severe) who receive front-line RVd for ≥ 3 cycles may see improvement in renal function at 3 mos, regardless of transplant eligibility. RVd therefore can potentially be used in pts with RI. This analysis provides real-world data that support further investigation of RVd treatment in pts with moderate or severe RI. Clinical trial information: NCT01081028 . [Table: see text]

8507 Background: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous stem cell transplantation (ASCT) has improved outcomes for patients with multiple myeloma (MM), but those with high risk MM (HRMM) have a poor long-term prognosis. To date, no trials have addressed optimal treatment for these patients. Methods: S1211 is a randomized phase II trial (NCT01668719) comparing 8 cycles of lenalidomide, bortezomib and dexamethasone (RVd) induction followed by dose-attenuated RVd maintenance until disease progression with or without elotuzumab. Stem cell collection was allowed, but ASCT was deferred until progression. HRMM was defined by one of the following: gene expression profiling high-risk (GEPhi), t(14; 16), t(14; 20), del(17p) or amplification 1q21, primary plasma cell leukemia (pPCL) and elevated serum LDH (> 2X ULN). Median progression-free survival (PFS) was the primary end-point, using a one-sided stratified log-rank test at a one-sided significance level of 0.1. Secondary endpoints included overall response rate (ORR), adverse events (AE), serious adverse events (SAE) and OS. Response was assessed using the IMWG 2009 criteria. Results: S1211 enrolled 103 evaluable patients, RVd n = 54, RVd-Elo n = 49. 75% had ISS II/III, 47% amp1q21, 38% del17p, 12% t(14; 16), 9% GEPhi, 7% pPCL, 5% t(14; 20) and 4% elevated serum LDH (18.5% > 1 feature). With median follow-up of 53 months (mos.), no difference in median PFS was observed [RVd-Elo = 31 mos., RVd = 34 mos.,HR = 0.968 (80% CI = 0.697-1.344), p = 0.449]. No difference in OS was observed [RVd-Elo = 68 mos, RVd = not reached, HR = 1.279 (80% CI: 0.819, 2.000), p-value = 0.478]. 72% pts had > Grade 3 AEs, no differences in the safety profile were observed except >Grade 3 infections (RVd 8%, RVd-Elo 16%), >Grade 3 sensory neuropathy (RVd 8%, RVd-Elo 13%). Conclusions: In the first randomized HRMM study reported to date, the addition of elotuzumab to RVd induction and maintenance did not improve patient outcomes. However, the PFS and OS seen in both arms of the study exceeded the original statistical assumptions and support the role for PI/IMiD combination maintenance therapy for this patient population. The S1211 data will serve as an important benchmark for future HRMM clinical trials. Clinical trial information: NCT01668719 .

Abstract Patients with chronic lymphocytic leukemia (CLL) are characterized by monoclonal expansion of CD5+CD23+CD27+CD19+κ/λ+ B lymphocytes and are clinically noted to have profound immune suppression. In these patients, it has been recently shown that a subset of B cells possesses regulatory functions and secretes high levels of interleukin 10 (IL-10). Our investigation identified that CLL cells with a CD19+CD24+CD38hi immunophenotype (B regulatory cell [Breg]–like CLL cells) produce high amounts of IL-10 and transforming growth factor β (TGF-β) and are capable of transforming naive T helper cells into CD4+CD25+FoxP3+ T regulatory cells (Tregs) in an IL-10/TGF-β-dependent manner. A strong correlation between the percentage of CD38+ CLL cells and Tregs was observed. CD38hi Tregs comprised more than 50% of Tregs in peripheral blood mononuclear cells (PBMCs) in patients with CLL. Anti-CD38 targeting agents resulted in lethality of both Breg-like CLL and Treg cells via apoptosis. Ex vivo, use of anti-CD38 monoclonal antibody (mAb) therapy was associated with a reduction in IL-10 and CLL patient-derived Tregs, but an increase in interferon-γ and proliferation of cytotoxic CD8+ T cells with an activated phenotype, which showed an improved ability to lyse patient-autologous CLL cells. Finally, effects of anti-CD38 mAb therapy were validated in a CLL–patient-derived xenograft model in vivo, which showed decreased percentage of Bregs, Tregs, and PD1+CD38hiCD8+ T cells, but increased Th17 and CD8+ T cells (vs vehicle). Altogether, our results demonstrate that targeting CD38 in CLL can modulate the tumor microenvironment; skewing T-cell populations from an immunosuppressive to immune-reactive milieu, thus promoting immune reconstitution for enhanced anti-CLL response.