Efficacy of isatuximab in combination with steroids for the treatment of relapsed/refractory multiple myeloma patients exhibiting only biochemical progression-A single center retrospective study.

OBJECTIVES: Isatuximab is approved for treatment of relapsed/refractory multiple myeloma (RRMM) with dexamethasone and carfilzomib or pomalidomide. Patients receiving these three-drug regimens have exhibited more Grade ≥ 3 adverse events (AEs) compared to the two-drug class combination of isatuximab and steroids alone. Thus, this single-center retrospective study investigated the efficacy of isatuximab with dexamethasone and methylprednisolone (ISAdm) for RRMM patients showing only biochemical progression (BP) of their disease. METHODS: Twenty-four RRMM patients exhibiting only BP were administered isatuximab at 10 mg/kg with dexamethasone once weekly for cycle 1 of a 28-day cycle, followed by every other week for each cycle thereafter. Starting in cycle 2, oral methylprednisolone was added every other day stopping 48 h before and starting 48 h after each dexamethasone infusion. RESULTS: Overall response rate and clinical benefit rate were 63% and 79%, respectively. Progression free survival was 12.9 months. There were only 5 AEs of Grade ≥ 3 which included lymphocytopenia (13%), leukopenia (4%), and neutropenia (4%). No Grade ≥ 3 AE related to respiratory infection, anemia, or thrombocytopenia were reported. CONCLUSION: This study shows that the two-drug class combination of ISAdm is an effective and well tolerated treatment option for RRMM patients exhibiting only BP.

Loss of anti-spike antibodies following mRNA vaccination for COVID-19 among patients with multiple myeloma.

BACKGROUND: Multiple myeloma (MM) patients have variable responses to mRNA vaccination to COVID-19. Little is known regarding their vaccine-induced antibody levels over time. METHODS: We monitored spike IgG antibody levels over 24 weeks among a subset of 18 MM patients who showed a full response after two mRNA vaccinations. RESULTS: MM patients had a more rapid decline in antibody levels as compared to eight healthy controls, with power law half-lives of 72 days (vs. 107 days) and exponential half-lives of 37 days (vs. 51 days). The patients with longer SARS-CoV-2 antibody half-lives were more likely to have undetectable monoclonal protein than those with shorter half-lives, suggesting better disease control may correlate with longer duration of vaccine-induced antibodies. Regardless, by 16 weeks post-second dose of mRNA vaccination, the majority of patients had antibody levels below 250 binding arbitrary units per milliliter, which would be unlikely to contribute to preventing COVID-19. CONCLUSIONS: Thus, even MM patients who respond adequately to vaccination are likely to require more frequent booster doses than the general population.