Clonal hematopoiesis is associated with adverse outcomes in multiple myeloma patients undergoing transplant.

Multiple myeloma (MM) is a plasma-cell neoplasm that is treated with high-dose chemotherapy, autologous stem cell transplant (ASCT) and long-term immunomodulatory drug (IMiD) maintenance. The presence of somatic mutations in the peripheral blood is termed clonal hematopoiesis of indeterminate potential (CHIP) and is associated with adverse outcomes. Targeted sequencing of the stem cell product from 629 MM patients treated by ASCT at the Dana-Farber Cancer Institute (2003-2011) detects CHIP in 136/629 patients (21.6%). The most commonly mutated genes are DNMT3A, TET2, TP53, ASXL1 and PPM1D. Twenty-one from fifty-six patients (3.3%) receiving first-line IMiD maintenance develop a therapy-related myeloid neoplasm (TMN). However, regardless of CHIP status, the use of IMiD maintenance associates with improved PFS and OS. In those not receiving IMiD maintenance, CHIP is associated with decreased overall survival (OS) (HR:1.34, p = 0.02) and progression free survival (PFS) (HR:1.45, p < 0.001) due to an increase in MM progression.

A Phase Ib/II Trial of the First-in-Class Anti-CXCR4 Antibody Ulocuplumab in Combination with Lenalidomide or Bortezomib Plus Dexamethasone in Relapsed Multiple Myeloma.

PURPOSE: Ulocuplumab (BMS-936564) is a first-in-class fully human IgG4 monoclonal anti-CXCR4 antibody that inhibits the binding of CXCR4 to CXCL12. PATIENTS AND METHODS: This phase Ib/II study aimed to determine the safety and tolerability of ulocuplumab alone and in combination with lenalidomide and dexamethasone (Arm A), or bortezomib and dexamethasone (Arm B), in patients with relapsed/refractory multiple myeloma. RESULTS: Forty-six patients were evaluated (median age, 60 years; range, 53-67). The median number of prior therapies was 3 (range, 1-11), with 70% of subjects having received ≥3. This trial had a dose-escalation and a dose-expansion part. Using a 3+3 design on both arms of the trial, ulocuplumab's dose was escalated to a maximum of 10 mg/kg without reaching MTD. The most common treatment-related adverse events (AE) were neutropenia (13 patients, 43.3%) in Arm A and thrombocytopenia (6 patients, 37.5%) in Arm B. No deaths related to study drugs occurred. The combination of ulocuplumab with lenalidomide and dexamethasone showed a high response rate (PR or better) of 55.2% and a clinical benefit rate of 72.4%, even in patients who had been previously treated with immunomodulatory agents (IMiD). CONCLUSIONS: This study showed that blockade of the CXCR4-CXCL12 axis by ulocuplumab is safe with acceptable AEs and leads to a high response rate in combination with lenalidomide and dexamethasone in patients with relapsed/refractory myeloma, making CXCR4 inhibitors a promising class of antimyeloma drugs that should be further explored in clinical trials.

Phase I/II trial of the CXCR4 inhibitor plerixafor in combination with bortezomib as a chemosensitization strategy in relapsed/refractory multiple myeloma.

We tested the hypothesis that using CXCR4 inhibition to target the interaction between the tumor cells and the microenvironment leads to sensitization of the tumor cells to apoptosis. Eligibility criteria included multiple myeloma (MM) patients with 1-5 prior lines of therapy. The purposes of the phase I study were to evaluate the safety and maximal-tolerated dose (MTD) of the combination. The treatment-related adverse events and response rate of the combination were assessed in the phase II study. A total of 58 patients were enrolled in the study. The median age of the patients was 63 years (range, 43-85), and 78% of them received prior bortezomib. In the phase I study, the MTD was plerixafor 0.32 mg/kg, and bortezomib 1.3 mg/m2 . The overall response rate for the phase II study was 48.5%, and the clinical benefit rate 60.6%. The median disease-free survival was 12.6 months. The CyTOF analysis demonstrated significant mobilization of plasma cells, CD34+ stem cells, and immune T cells in response to plerixafor. This is an unprecedented study that examines therapeutic targeting of the bone marrow microenvironment and its interaction with the tumor clone to overcome resistance to therapy. Our results indicate that this novel combination is safe and that the objective response rate is high even in patients with relapsed/refractory MM. ClinicalTrials.gov, NCT00903968.

Progression Risk Stratification of Asymptomatic Waldenström Macroglobulinemia.

BACKGROUND: Waldenström macroglobulinemia (WM) is preceded by asymptomatic WM (AWM), for which the risk of progression to overt disease is not well defined. METHODS: We studied 439 patients with AWM, who were diagnosed and observed at Dana-Farber Cancer Institute between 1992 and 2014. RESULTS: During the 23-year study period, with a median follow-up of 7.8 years, 317 patients progressed to symptomatic WM (72%). Immunoglobulin M 4,500 mg/dL or greater, bone marrow lymphoplasmacytic infiltration 70% or greater, ß2-microglobulin 4.0 mg/dL or greater, and albumin 3.5 g/dL or less were all identified as independent predictors of disease progression. To assess progression risk in patients with AWM, we trained and cross-validated a proportional hazards model using bone marrow infiltration, immunoglobulin M, albumin, and beta-2 microglobulin values as continuous measures. The model divided the cohort into three distinct risk groups: a high-risk group with a median time to progression (TTP) of 1.8 years, an intermediate-risk group with a median TTP of 4.8 years, and a low-risk group with a median TTP of 9.3 years. We validated this model in two external cohorts, demonstrating robustness and generalizability. For clinical applicability, we made the model available as a Web page application ( www.awmrisk.com ). By combining two cohorts, we were powered to identify wild type MYD88 as an independent predictor of progression (hazard ratio, 2.7). CONCLUSION: This classification system is positioned to inform patient monitoring and care and, for the first time to our knowledge, to identify patients with high-risk AWM who may need closer follow-up or benefit from early intervention.

A Phase I/II Study of Evofosfamide, A Hypoxia-activated Prodrug with or without Bortezomib in Subjects with Relapsed/Refractory Multiple Myeloma.

PURPOSE: The presence of hypoxia in the diseased bone marrow presents a new therapeutic target for multiple myeloma. Evofosfamide (formerly TH-302) is a 2-nitroimidazole prodrug of the DNA alkylator, bromo-isophosphoramide mustard, which is selectively activated under hypoxia. This trial was designed as a phase I/II study investigating evofosfamide in combination with dexamethasone, and in combination with bortezomib and dexamethasone in relapsed/refractory multiple myeloma. PATIENTS AND METHODS: Fifty-nine patients initiated therapy, 31 received the combination of evofosfamide and dexamethasone, and 28 received the combination of evofosfamide, bortezomib, and dexamethasone. Patients were heavily pretreated with a median number of prior therapies of 7 (range: 2-15). All had previously received bortezomib and immunomodulators. The MTD, treatment toxicity, and efficacy were determined. RESULTS: The MTD was established at 340 mg/m2 evofosfamide + dexamethasone with dose-limiting mucositis at higher doses. For the combination of evofosfamide, bortezomib, and dexamethasone, no patient had a dose-limiting toxicity (DLT) and the recommended phase II dose was established at 340 mg/m2. The most common ≥grade 3 adverse events (AE) were thrombocytopenia (25 patients), anemia (24 patients), neutropenia (15 patients), and leukopenia (9 patients). Skin toxicity was reported in 42 (71%) patients. Responses included 1 very good partial response (VGPR), 3 partial response (PR), 2 minor response (MR), 20 stable disease (SD), and 4 progressive disease (PD) for evofosfamide + dexamethasone and 1 complete response (CR), 2 PR, 1 MR, 18 SD, and 5 PD for evofosfamide + bortezomib + dexamethasone. Disease stabilization was observed in over 80% and this was reflective of the prolonged overall survival of 11.2 months. CONCLUSIONS: Evofosfamide can be administered at 340 mg/m2 twice a week with or without bortezomib. Clinical activity has been noted in patients with heavily pretreated relapsed refractory multiple myeloma.

Blood-brain-barrier spheroids as an in vitro screening platform for brain-penetrating agents.

Culture-based blood-brain barrier (BBB) models are crucial tools to enable rapid screening of brain-penetrating drugs. However, reproducibility of in vitro barrier properties and permeability remain as major challenges. Here, we report that self-assembling multicellular BBB spheroids display reproducible BBB features and functions. The spheroid core is comprised mainly of astrocytes, while brain endothelial cells and pericytes encase the surface, acting as a barrier that regulates transport of molecules. The spheroid surface exhibits high expression of tight junction proteins, VEGF-dependent permeability, efflux pump activity and receptor-mediated transcytosis of angiopep-2. In contrast, the transwell co-culture system displays comparatively low levels of BBB regulatory proteins, and is unable to discriminate between the transport of angiopep-2 and a control peptide. Finally, we have utilized the BBB spheroids to screen and identify BBB-penetrant cell-penetrating peptides (CPPs). This robust in vitro BBB model could serve as a valuable next-generation platform for expediting the development of CNS therapeutics.