The impact of lenalidomide maintenance on second-line chemotherapy in transplant eligible patients with multiple myeloma.

OBJECTIVES: To understand the impact of therapy sequencing on progression-free (PFS) and overall survival (OS) for the treatment of multiple myeloma (MM). The use of daily, low-dose, lenalidomide maintenance (LM) has raised concern for fostering resistance, preventing its use in the relapsed setting. METHODS: We conducted a retrospective analysis of survival outcomes from the Canadian Myeloma Research Group Database. Patients were grouped based on receipt of LM after autologous stem cell transplant and receipt of lenalidomide in second-line therapy, 575 patients were included. RESULTS: Patients treated with LM had statistically similar 2nd PFS when re-exposed to lenalidomide in second-line therapy compared to those receiving non-lenalidomide-containing regimens (10.2 vs 14.0 months, P =.53). This cohort also had the longest 2nd OS, 18 months longer than patients treated with LM who did not receive lenalidomide at relapse (55.3 vs 37 months, P =.004). Patients treated with LM also demonstrated deeper responses to second-line therapy than their non-LM counterparts. CONCLUSION: Our data suggest that patients progressing on LM who receive lenalidomide-containing therapy at first relapse have comparable 2nd PFS and better 2nd OS compared to non-lenalidomide-containing second-line regimens. Identification of patients mostly likely to benefit from further lenalidomide-containing therapy is paramount.

Mortality from Multiple Myeloma Within One Year Following Autologous Stem Cell Transplantation: Defining an Ultra-high Risk Population.

Despite improvements in therapy, approximately 5% of patients who undergo autologous stem cell transplantation (ASCT) experience early mortality (EM), death within 1 year of transplant (EM post-ASCT). Such patients tend to have few comorbidities suggesting their EM is owing to aggressive underlying disease. We sought to characterize this ultra-high risk population through a retrospective review of patients with newly diagnosed multiple myeloma (MM) treated with first-line ASCT. Patients who died within 1 year of ASCT were matched for age, sex, and year of transplant in a 1:2 fashion with a control group. Of 962 transplants performed between January 1, 2007, and May 1, 2019, 41 patients (4.3%) died within 1 year of ASCT from MM-related causes. In a multivariate analysis, anemia, hypercalcemia, high-risk cytogenetics, and elevated lactate dehydrogenase were associated with EM post-ASCT. Forty patients (97.6%) received at least 1 novel agent. Most patients with EM post-ASCT received second-line chemotherapy (80.5%), although survival from initiation of second-line chemotherapy was only 2.1 months. The primary reason for not receiving second-line therapy was rapid relapse. Clinical parameters reflecting disease burden, as well as high-risk cytogenetics, are associated with EM post-ASCT. These patients have a dismal overall survival despite significant advances in treatment of patients with relapsed or refractory myeloma. Further study of these ultra-high risk patients is required to improve disease management and may give further insights into the biology of relapse and resistance in myeloma.