Multiple Myeloma: Impact of Time to Transplant on the Outcome.

Background: Autologous stem cell transplant (ASCT) is a standard therapy for transplant eligible patients of multiple myeloma (MM). To evaluate impact of time to transplant on subsequent outcomes, we analyzed data on consecutive MM patients who received novel agents-based induction prior to transplant.

Methods: Between 2006 and 2019, 363 MM patients underwent ASCT. Patients' median age was 52 years, ranging from 20 to 72 years, 233 (64.2%) were males. Median interval from diagnosis to transplant was 11.5 months (range, 4-67.5); 201 (55.4%) patients underwent ASCT within 12 months (early) and 162 (44.6%) beyond 12 months since diagnosis (delayed ASCT). Primary objective was progression-free survival. Secondary objectives were-response rate to transplant, overall survival (OS), and transplant-related mortality (TRM).

Results: Post-ASCT complete response (CR) (77.1% vs. 64.8%; P < .025) and CR+ very good partial response rate (89% vs. 81.5%; P < .03) was higher for early ASCT cohort. Engraftment characteristics, regimen-related toxicities, and day +100 TRM (3.5% vs 3.7%; P = .564) were similar in 2 cohorts. Median OS for early versus late cohort from date of diagnosis is 127.0 (95% CI, 98.9-155.1) versus 104.5 months (95% CI, 79.3-129.6; P = .356) and from date of transplant is 119.0 (95% CI, 93.4-144.6) versus 89.5 months (95% CI, 57.4-121.6), P < .02. Median PFS is better for early transplant cohort; 69.5 (95% CI, 56.7-82.3) versus 50.0 months (95% CI, 35.6-64.4), P < .05, respectively.

Conclusion: Early transplant for myeloma is associated with higher response rate and better progression-free survival.