Choosing treatment options for patients with relapsed/refractory multiple myeloma

Incidence of Venous Thromboembolism in Multiple Myeloma Patients across Different Regimens: Role of Procoagulant Microparticles and Cytokine Release

Introduction: Multiple myeloma (MM) is characterized by a high prevalence of thrombotic complications. Microvesicles (MVs) are small membrane vesicles released from activated cells, and they may potentially contribute to thrombosis. Methods: We have evaluated the plasma levels of MVs and cytokines (IL-10, IL-17, and TGF-β in MM and Watch and Wait Smoldering MM (WWSMM) from patients and related them to thrombotic complications. The secondary aim was to assess the impact of ongoing therapy on MV and on cytokine levels. Result: 92 MM and 31 WWSMM were enrolled, and 14 (12%) experienced a thrombotic episode. Using univariate analysis, TGF-β and MV were significantly higher in patients with thrombotic events (p = 0.012; p = 0.008, respectively). Utilizing a Cox proportional hazard model, we confirmed this difference (TGF-β p = 0.003; Odds ratio 0.001, 95% CI 0−0.003 and MV p = 0.001; Odds ratio 0.003, 95% CI 0.001−0.005). Active treatment management displayed higher levels of MV (p < 0.001) and lower levels of glomerular filtration-rate (p < 0.001), IL-17 (p < 0.001) as compared to the WWSMM group. The TGF-β values of immunomodulatory derivatives patients were lower in the WWSMM (p < 0.001) and Dexamethasone/Bortezomib subgroup (p < 0.001). Conclusion: The increased levels of MVs in active regimens add insight into the mechanisms of hypercoagulation in MM. In addition, a role for cytokine-related thrombosis is also suggested.

Low-dose lenalidomide and dexamethasone combination treatment in elderly patients with relapsed and refractory multiple myeloma

OBJECTIVE

This study investigated the efficacy and safety of low-dose lenalidomide combined with dexamethasone in elderly patients with relapsed and refractory multiple myeloma (MM).

METHODS

Thirty-two elderly patients with refractory and recurrent MM (median age: 64 years) were treated with low-dose lenalidomide (LD-R) combined with dexamethasone (D). LD-R (10 mg/d) was administered orally for 21 days and D (40 mg/d) was administered twice a day on days 1-4, 9-12, and 17-20. The treatment lasted 2-8 28-day cycles.

RESULTS

After two cycles, the complete, very good partial, and partial remission rates were 12.5% (4/32), 25.0% (8/32), and 34.4% (11/32), respectively. The overall response rate was 71.9% (23/32). After a 24-month follow-up, 23 patients responded to therapy, three were in complete remission, four were stable, and 16 exhibited disease progression. In addition, median time-to-progression was 13 months. Observed side effects were hypodynamia, gastrointestinal reaction, peripheral neuritis, and mild hypocytosis.

CONCLUSION

Low-dose lenalidomide in combination with dexamethasone is an effective and safe treatment for relapsed and refractory MM in elderly patients.

SAR650984 directly induces multiple myeloma cell death via lysosomal-associated and apoptotic pathways, which is further enhanced by pomalidomide

The anti-CD38 monoclonal antibody SAR650984 (SAR) is showing promising clinical activity in treatment of relapsed and refractory multiple myeloma (MM). Besides effector-mediated antibody-dependent cellular cytotoxicity and complement-mediated cytotoxicity, we here define molecular mechanisms of SAR-directed MM cell death and enhanced anti-MM activity triggered by SAR with Pomalidomide (Pom). Without Fc-cross-linking agents or effector cells, SAR specifically induces homotypic aggregation (HA)-associated cell death in MM cells dependent on the level of cell surface CD38 expression, actin cytoskeleton and membrane lipid raft. SAR and its F(ab)'2 fragments trigger caspase 3/7-dependent apoptosis in MM cells highly expressing CD38, even with p53 mutation. Importantly, SAR specifically induces lysosome-dependent cell death (LCD) by enlarging lysosomes and increasing lysosomal membrane permeabilization associated with leakage of cathepsin B and LAMP-1, regardless of the presence of interleukin-6 or bone marrow stromal cells. Conversely, the lysosomal vacuolar H+-ATPase inhibitor blocks SAR-induced LCD. SAR further upregulates reactive oxygen species. Pom enhances SAR-induced direct and indirect killing even in MM cells resistant to Pom/Len. Taken together, SAR is the first therapeutic monoclonal antibody mediating direct cytotoxicity against MM cells via multiple mechanisms of action. Our data show that Pom augments both direct and effector cell-mediated MM cytotoxicity of SAR, providing the framework for combination clinical trials.