Survival Outcomes of Upfront Transplant in Black Patients with MM

Black patients with multiple myeloma (MM) who receive upfront hematopoietic autologous cell transplantation (ASCT) have similar survival outcomes to their non-Black counterparts, according to a research letter published in the American Journal of Hematology.

In total, 668 patients were evaluated, including 126 Black patients and 542 white patients. The average age was 56.8 years for Black patients, and 61.5 years for white patients. Rates of International Staging System stage III disease were comparable between groups. The rate of high-risk disease was 20.6% versus 27.7% for Black and white patients, respectively.

Induction therapies utilized across the entire cohort were an immunomodulatory drug (IMiD; 8.9%), an IMiD plus a proteasome inhibitor (PI; 54.6%), a regimen of cyclophosphamide, bortezomib, and dexamethasone (19.8%), bortezomib plus dexamethasone (13.8%), or another regimen (2.8%). The overall response rate (ORR) to induction was 94.9%, with 7.4% achieving a complete response (CR), 41.5% achieving a very good partial response (VGPR), and 43.7% had a partial response (PR). Two percent of patients had stable disease after treatment and 5.1% had progressive disease.

More than half of patients (56.7%) received maintenance therapy with an IMiD; 11.8% with a PI plus an IMiD; 6.9% with a PI; 4.0% with an IMiD plus elotuzumab; and 0.3% with another regimen. Twenty percent of patients did not receive maintenance therapy.

Almost all Black patients responded to treatment with ASCT (ORR=97.6%; n = 123), compared with an ORR of 97.9% among white patients. Rates of CR, VGPR, and PR among Black patients was 27.8%, 47.6% and 19.8%, respectively, and 26.2%, 48.0% and 26.2%, respectively, in white patients (P = 0.79).

Median follow-up was 70.8 months. Rates of four-year progression-free survival (PFS) were 48.4% (95% confidence interval [CI], 40.4-58.1) and 45.0% (95% CI, 40.9-49.5) for Black versus white patients, respectively. Four-year overall survival (OS) was 78.7% (95% CI, 71.8-86.3) and 77.9% (95% CI, 74.4-81.5), respectively.

Median length of PFS was 46.0 months for Black patients (95% CI, 35.5-54.7) and 40.8 months for white patients (95% CI, 35.9-47.7). Median overall survival was 101.1 months for Black patients (95% CI, 88.0-Not reached) and 97.0 for white patients (95% CI, 85.0-Not reached; P = 0.382). According to multivariable analysis, neither race nor translocation t(11;14) presence were significantly associated with survival.

The investigators also conducted a propensity-matched cohort analysis of 125 Black patients and 125 white patients. Disease responses after ASCT were not significantly different between the two patient groups in this analysis (P = 0.765).