Efficacy and Safety of Anti-CD38 Monoclonal Antibodies in Patients with Relapsed or Refractory Multiple Myeloma: A Meta-Analysis of Randomized Clinical Trials

The benefit of associating anti-CD38 monoclonal antibodies to proteasome inhibitor (PI)/immunomodulatory agent (IA) and dexamethasone in the treatment of patients with relapsed or refractory multiple myeloma (MM) remains unclear. PubMed, Embase, and Cochrane Library databases were searched for randomized controlled trials that investigated the addition of anti-CD38 monoclonal antibodies to a therapy composed of PI/IA and dexamethasone versus PI/IA and dexamethasone alone for treating relapsed or refractory MM. Hazard ratios (HRs) or risk ratios (RRs) were computed for binary endpoints, with 95% confidence intervals (CIs). Six studies comprising 2191 patients were included. Anti-CD38 monoclonal antibody significantly improved progression-free survival (HR 0.52; 95% CI 0.43-0.61; p < 0.001) and overall survival (HR 0.72; 95% CI 0.63-0.83; p < 0.001). There was a significant increase in hematological adverse events, such as neutropenia (RR 1.41; 95% CI 1.26-1.58; p < 0.01) and thrombocytopenia (RR 1.14; 95% CI 1.02-1.27; p = 0.02), in the group treated with anti-CD38 monoclonal antibody. Also, there was a significant increase in non-hematological adverse events, such as dyspnea (RR 1.72; 95% CI 1.38-2.13; p < 0.01) and pneumonia (RR 1.34; 95% CI 1.13-1.59; p < 0.01), in the group treated with anti-CD38 monoclonal antibody. In conclusion, the incorporation of an anti-CD38 monoclonal antibody demonstrated a promising prospect for reshaping the established MM treatment paradigms.

Practice patterns and outcomes for triple-class exposed patients with relapsed/refractory multiple myeloma in Japan

Aim: Treatment options for triple-class exposed (TCE) patients with multiple myeloma (MM) in Japan are limited. Materials & methods: Retrospective observational study using the Medical Data Vision database (April 2008-April 2021). Eligible adults with MM received a new post-TCE treatment. Treatments, healthcare resource utilization (HCRU) and costs (per patient per month [PPPM]) were analyzed with subgroup analyses by prior stem cell transplantation (SCT vs No SCT). Results: Of 459 TCE patients, 216 (47%) had post-TCE treatment of whom 194 (90%) had no prior SCT. Median duration of the first post-TCE line of therapy (LOT) was 2 months; 49% of No SCT patients received a subsequent LOT. Total healthcare costs were comparable between No SCT and SCT groups (¥1.3 million PPPM each; US$12,328 and $12,391, respectively), driven by treatment costs. Median post-index overall survival (n = 216) was 15.8 months (95% CI: 10.5, 22.3). Conclusion: New treatments with better effectiveness are needed for patients with TCE MM in Japan.

Depletion of CD38-positive regulatory T cells by anti-CD38 monoclonal antibodies induces a durable response to SARS-CoV-2 vaccination in patients with plasma cell dyscrasia

This study reports the relationship between CD38⁺ regulatory T cells (Tregs) and messenger RNA coronavirus disease 2019 (mRNA-COVID-19) vaccination in 60 patients with plasma cell dyscrasia. Patients treated with anti-CD38 monoclonal antibodies (mAbs) had significantly lower CD38⁺ Tregs than those not treated (0.9 vs. 13.2/μl). Late-responders, whose antibody titres increased from weeks 4-12 after the second vaccination, had significantly lower CD38⁺ Treg counts than non-late-responders (2.5 vs. 10.3/μl). Antibody titres in patients with lower CD38⁺ Treg levels were maintained from weeks 4-12 but decreased in those with higher CD38⁺ Treg levels. Therefore, depletion of CD38⁺ Tregs by anti-CD38 mAbs may induce a durable response to mRNA-COVID-19 vaccination.

Isatuximab for relapsed/refractory multiple myeloma: review of key subgroup analyses from the Phase III ICARIA-MM study

In the Phase III ICARIA-MM study (NCT02990338), the addition of the anti-CD38 monoclonal antibody isatuximab to pomalidomide and dexamethasone led to increased progression-free survival and improved response rates in patients with relapsed/refractory multiple myeloma. There is an unmet treatment need, particularly among patients with poor prognoses, including those with high-risk cytogenetics, those who have renal impairment, those who are elderly and those who are refractory to prior lines of treatment. In this review, the subgroup analyses from the ICARIA-MM study, representing subpopulations with poor prognostic factors, are discussed. Overall, the addition of isatuximab to pomalidomide and dexamethasone improved progression-free survival and disease response rates across different subgroups, regardless of prognostic factor.

Isatuximab plus pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma according to prior lines of treatment and refractory status: ICARIA-MM subgroup analysis

Patients with relapsed/refractory multiple myeloma (RRMM) experience several relapses, and become refractory to successive therapies. In the ICARIA-MM trial (NCT02990338), isatuximab plus pomalidomide-dexamethasone prolonged median progression-free survival (PFS) in patients with RRMM. This subgroup analysis of ICARIA-MM assessed the treatment benefit of isatuximab by prior lines of therapy and refractory status. A total of 307 patients were randomized to isatuximab-pomalidomide-dexamethasone (n = 154) or pomalidomide-dexamethasone (n = 153). Isatuximab (10 mg/kg intravenously) was given weekly in the first 28-day cycle, then every other week. Standard pomalidomide-dexamethasone doses were given. PFS was assessed by prior lines and refractory status. Overall, 102 (66 %) patients receiving isatuximab-pomalidomide-dexamethasone and 101 (66 %) patients receiving pomalidomide-dexamethasone had received 2-3 prior lines; 52 (34 %) and 52 (34 %) had received >3 prior lines, respectively. Median PFS was higher with isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone for patients who received 2-3 prior lines of therapy (12.3 vs. 7.8 months) and >3 prior lines of therapy (9.4 vs. 4.3 months). Median PFS was higher with isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone for patients who were lenalidomide-refractory (11.4 vs. 5.6 months), lenalidomide-refractory at last line (11.6 vs. 5.7 months), refractory to a proteasome inhibitor (PI) (11.4 vs. 5.6 months), and double-refractory (11.2 vs. 4.8 months). Overall response rate (ORR) in patients receiving isatuximab-pomalidomide-dexamethasone versus pomalidomide-dexamethasone was 59.0 % versus 31.4 % in lenalidomide-refractory; 60.2 % versus 32.2 % in PI-refractory; and 58.6 % versus 29.9 % in double-refractory patients. Isatuximab-pomalidomide-dexamethasone improved PFS and ORR regardless of prior lines of therapy or refractory status, consistent with the benefit in the overall population.

Treatment Strategies Considering Micro-Environment and Clonal Evolution in Multiple Myeloma

Simple Summary

Multiple myeloma is an uncurable hematological malignancy, although the prognosis of myeloma patients is getting better using proteasome inhibitors (PIs), immune modulatory drugs (IMiDs), monoclonal antibodies (MoAbs), and cytotoxic agents. Drug resistance makes myeloma difficult to treat and it can be subdivided into two broad categories: de novo and acquired. De novo drug resistance is associated with the bone marrow microenvironment including bone marrow stromal cells, the vascular niche and endosteal niche. Acquired drug resistance is related to clonal evolution and non-genetic diversity. The initial treatment plays the most important role considering de novo and acquired drug resistance and should contain PIs, IMIDs, MoAbs, and autologous stem cell transplantation because these treatments improve the bone marrow microenvironment and might prevent clonal evolution via sustained deep response including minimal residual disease negativity.

Abstract

Multiple myeloma is an uncurable hematological malignancy because of obtained drug resistance. Microenvironment and clonal evolution induce myeloma cells to develop de novo and acquired drug resistance, respectively. Cell adhesion-mediated drug resistance, which is induced by the interaction between myeloma and bone marrow stromal cells, and soluble factor-mediated drug resistance, which is induced by cytokines and growth factors, are two types of de novo drug resistance. The microenvironment, including conditions such as hypoxia, vascular and endosteal niches, contributes toward de novo drug resistance. Clonal evolution was associated with acquired drug resistance and classified as branching, linear, and neutral evolutions. The branching evolution is dependent on the microenvironment and escape of immunological surveillance while the linear and neutral evolution is independent of the microenvironment and associated with aggressive recurrence and poor prognosis. Proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), monoclonal antibody agents (MoAbs), and autologous stem cell transplantation (ASCT) have improved prognosis of myeloma via improvement of the microenvironment. The initial treatment plays the most important role considering de novo and acquired drug resistance and should contain PIs, IMIDs, MoAb and ASCT. This review summarizes the role of anti-myeloma agents for microenvironment and clonal evolution and treatment strategies to overcome drug resistance.