PURPOSE Multiple myeloma (MM) is a genetically heterogeneous malignancy characterized by variable treatment responses. Although numerous drugs have been approved in recent years, the ability to predict treatment response and tailor individual therapy is limited by the absence of robust predictive biomarkers. The goal of this clinical trial was to use ex vivo, high-throughput screening (HTS) of 170 compounds to predict response among patients with relapsed or refractory MM and inform the next treatment decisions. Additionally, we integrated HTS with multi-omic analysis to uncover novel associations between in vitro drug sensitivity and gene expression and mutation profiles. MATERIALS AND METHODS Twenty-five patients with relapsed or refractory MM underwent a screening bone marrow or soft tissue biopsy. Sixteen patients were found to have sufficient plasma cells for HTS. Targeted next-generation sequencing was performed on plasma cell-free DNA from all patients who underwent HTS. RNA and whole-exome sequencing of bone marrow plasma cells were performed on eight and seven patients, respectively. RESULTS Results of HTS testing were made available to treating physicians within a median of 5 days from the biopsy. An actionable treatment result was identified in all 16 patients examined. Among the 13 patients who received assay-guided therapy, 92% achieved stable disease or better. The expression of 105 genes and mutations in 12 genes correlated with in vitro cytotoxicity. CONCLUSION In patients with relapsed or refractory MM, we demonstrate the feasibility of ex vivo drug sensitivity testing on isolated plasma cells from patient bone marrow biopsies or extramedullary plasmacytomas to inform the next line of therapy.
Background: The response to treatment for patients with relapsed/refractory multiple myeloma (MM) is highly variable. This may in part be related to the broad genomic heterogeneity that has been reported across individual patients. We hypothesize that in vitro functional drug screening and correlated genomic analyses of patient tumor cells is feasible and may improve clinical treatment response. To address this, we developed a custom high-throughput drug sensitivity (HTS) assay enabling simultaneous testing of 170 chemotherapy drugs and targeted inhibitors, as well as correlative gene expression and mutational analysis by next-generation sequencing. We report on the feasibility of this approach in a clinical trial enrolling patients with relapsed/refractory MM (NCT03389347). Patients and Methods: Twenty patients with relapsed/refractory MM or secondary plasma cell leukemia were enrolled in the study and 15 (9 female, 6 male) had a sufficient number of plasma cells for HTS. The average number of prior treatment regimens among the tested patients was 5.8 (range 3-11) and all had previously received a proteasome inhibitor and immunomodulatory drug and 8 had prior autologous stem cell transplants. Nine patients had stage III disease by the Revised International Staging System (R-ISS) and 4 had stage II disease. Eight patients exhibited high-risk cytogenetics, including 4 patients with del(17p), 5 patients with t(4;14), and 2 patients with t(14;16). The sources of plasma cells utilized for the HTS assay included bone marrow aspirate or core biopsies, soft tissue biopsies of plasmacytomas, and blood samples from patients with circulating plasma cells. Additional blood and bone marrow samples were obtained for RNA sequencing, whole-exome sequencing, and targeted sequencing of circulating tumor DNA. The CLIA approved HTS assay was performed at the Quellos HTS Core at the University of Washington using CD138+plasma cells isolated by magnetic bead separation. Tumor cells were tested against a panel of 170 drugs that includes conventional agents and targeted inhibitors, some FDA approved and others investigational. Cell viability was assessed at 72 hours by a luminescent cell viability assay (Cell Titer Glo, Promega) and drug response was determined using the concentration of experimental compound required to achieve 50% in vitro response inhibition (IC50) and area under the dose-response curve (AUC). Results: We report that the HTS assay can be completed in a median of 5 days from sampling (range 4-6 days), establishing feasibility. The mean percentage of bone marrow plasma cells among patients who could be tested was 56% compared to 5% for patients who had insufficient cells. We observed heterogeneity in patient genomic profiles and in vitro drug responses. The drugs with the highest in vitro response include those commonly used in MM such as bortezomib, ixazomib, carfilzomib, and panobinostat, as well as those under investigation including venetoclax and selinexor. Sensitivity was observed for drugs that have not been investigated for the treatment of MM including alvocidib and omacetaxine. Progression on prior therapy was not consistently predictive of in vitro drug responses and could be a consequence of some myeloma cells retaining sensitivity. Correlative genomic analyses were associated with in vitro drug responses for a subset of compounds. Among the 8 patients who received individualized therapy guided by the assay, 6 had an evaluable response and 5 (83%) achieved effective disease control (stable disease or better). Updated clinical treatment outcomes will be reported at the ASH conference. Conclusions: In this study, we successfully demonstrate the feasibility of a CLIA approved HTS assay capable of delivering actionable results in time to inform individualized treatment decisions for patients with MM. Correlative gene expression and mutational analysis are associated with in vitro drug response. Finally, we demonstrate that some of the patients who received treatment guided by the results of the HTS assay achieved a clinical response. These data suggest that using functional drug screening to predict sensitivity or resistance to both approved and experimental agents warrants further testing. Validation of the HTS assay in a larger population of MM patients holds the potential to improve treatment outcomes. Disclosures Cowan: Cellectar: Consultancy; Janssen: Consultancy, Research Funding; Abbvie: Research Funding; Celgene: Consultancy, Research Funding; Juno: Research Funding; Sanofi: Consultancy. Green:Celgene: Consultancy; Cellectar Biosciences: Research Funding; GSK: Consultancy; Juno Therapeutics: Consultancy, Patents & Royalties, Research Funding; Seattle Genetics: Research Funding. Libby:Alnylam: Consultancy; Abbvie: Consultancy; Pharmacyclics and Janssen: Consultancy; Akcea: Consultancy. Silbermann:Janssen, Sanofi: Other: Consultant/Advisor. Becker:The France Foundation: Honoraria; Accordant Health Services/Caremark: Consultancy; AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding. OffLabel Disclosure: We will discuss in-vitro sensitivity testing of drugs that have not been approved for the treatment of multiple myeloma.
Background: The treatment of multiple myeloma (MM) is optimized by use of combination regimens consisting of agents with different mechanisms of action. Panobinostat is a pan-inhibitor of histone deacetylases types I,II, and IV. Panobinostat, bortezomib, dexamethasone was shown to be an effective regimen (San Miguel et al Lancet Hematol 2016; Richardson et al Blood 2016), leading to the FDA approval of panobinostat for patients with relapsed/refractory MM. Carfilzomib is a proteasome inhibitor that was FDA approved in relapsed/refractory MM with the advantage of minimal neuropathy. Panobinostat and carfilzomib has also been shown to be a highly active regimen in relapsed/refractory MM with an overall response rate of up to 75% (Berdeja et al, Haematologica, 2015). With the heterogeneity of MM, individual patients exhibit wide variability in responses to drug combinations. A test that could predict patient responses to specific agents might enable clinicians to optimize therapy for patients, improving outcomes. We developed an in vitro high throughput drug sensitivity assay with formal synergy testing to predict response. In this ongoing trial, Panobinostat with Carfilzomib and Dexamethasone for Relapsed/Refractory Multiple Myeloma: Correlation with In Vitro Chemosensitivity Testing (NCT03256045), we will correlate individual patient in vitro sensitivity assay results with individual clinical response to the same triple drug regimen. Study Design and Methods: This study's objective is to directly demonstrate the utility of a high throughput drug sensitivity assay in determining biomarkers (e.g. individual IC50s, AUCs and/or synergy scores) to accurately predict response to combination therapy that was given prospectively to all enrolled patients. We are enrolling patients with relapsed/refractory MM by IMWG criteria with measurable disease defined by the detection of a quantifiable monoclonal protein in the urine or serum or an abnormal serum free light chain ratio. Additionally, patients must have adequate blood counts and organ function. Patients who have had prior autologous or allogeneic transplants or CAR-T cell therapy are eligible. The regimen consists of panobinostat 20 mg orally on days 1,3,5,15,17,19; carfilzomib 20 mg/m2/dose IV on days 1,2 of cycle 1, then dose escalation up to 45 mg/m2/dose days 8,9,15,16 and all days for subsequent cycles; and dexamethasone 20 mg orally on days of carfilzomib. Dose reductions of all three drugs are permitted per patient tolerance to allow continuation on study treatment. Up to 12 cycles of treatment are permitted. Patients are monitored by serial electrocardiograms and assessments of cardiac function. Safety parameters including adverse events are recorded. CD138+ plasma cells are procured from the patient bone marrow (aspiration and biopsy) and blood (when present) by magnetic bead separation. Cells are then added to 384-well plates and incubated overnight before the drugs are added. Cells are exposed to 8 concentrations (spanning 4 logs) of panobinostat, carfilzomib, or dexamethasone as singlet, doublet and triplet combinations for 72 hours. Cell viability is determined using CellTiter-Glo and IC50 and AUC values are are calculated by fitting data using least squares method to the standard four-parameter logistic model. Curve fitting is performed using IDBS XLFit software. The combination index is calculated by the method described by Chou and Talalay, Trends Pharmacol Sci 1983;4:450-4. Concentrations of Drug1 and Drug2 (that is, panobinostat and dexamethasone or panobinostat and carfilzomib) alone or in combinations are determined that give rise to 90% growth inhibition. At 90% Growth Inhibition, the Combination Index or CI = ([D1] in the combination / [D1] alone) + ([D2] in the combination / [D2] alone). All patients are treated with panobinostat, carfilzomib, and dexamethasone and evaluated for response using the IMWG response criteria. At the completion of enrollment at 35 patients, we plan to correlate the in vitro testing data with in vivo clinical response to determine appropriate biomarkers. This will be done by correlating the IC50s and AUCs for the individual drugs for responders vs. non-responders (including degree of response VGPR vs PR vs SD), as well as correlations of the synergy scores for each of the pairs of drugs in the responders vs. non-responders. Enrollment was initiated in April 2018. Disclosures Becker: Accordant Health Services/Caremark: Consultancy; AbbVie, Amgen, Bristol-Myers Squibb, Glycomimetics, Invivoscribe, JW Pharmaceuticals, Novartis, Trovagene: Research Funding; The France Foundation: Honoraria. Libby:Abbvie: Consultancy; Pharmacyclics and Janssen: Consultancy; Akcea: Consultancy; Alnylam: Consultancy. Cowan:Juno: Research Funding; Abbvie: Research Funding; Sanofi: Consultancy; Janssen: Consultancy, Research Funding; Cellectar: Consultancy; Celgene: Consultancy, Research Funding. Hammer:Glycomimetics: Consultancy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.