MAIA is a phase 3, randomized, open-label study that compared daratumumab plus lenalidomide and dexamethasone (D-Rd) with lenalidomide and dexamethasone (Rd) alone in patients newly diagnosed with multiple myeloma (MM) who are ineligible for autologous stem-cell transplant. The study demonstrated improved progression-free survival (PFS) and overall survival (OS) with D-Rd treatment until progression versus Rd alone. Because of the cost associated with long-term disease control, physicians and payers may seek to limit treatment duration as long as clinical benefit can be maintained. Moreau and colleagues presented findings from a post-hoc analysis of OS to determine the impact of treatment duration on long-term clinical outcomes.
The post-hoc analysis was performed based on D-Rd treatment duration, <18 versus ≥18 months, not including patients with MM who discontinued due to disease progression during the first 18 months. To determine the impact of discontinuing individual regimen components, an analysis was also performed in D-Rd patients who discontinued daratumumab or lenalidomide with or without dexamethasone but continued remaining treatment. An additional post-hoc analysis was performed in patients who received D-Rd or Rd for ≥9 or ≥18 months to assess the impact of treatment duration on PFS and OS.
After a median follow-up of 56.2 months, an OS benefit was seen in patients receiving D-Rd for ≥18 months versus patients who received D-Rd <18 months (hazard ratio [HR], 0.16; 95% confidence interval [CI], 0.1-0.25; P <.0001). In all, 48 D-Rd patients discontinued lenalidomide with or without dexamethasone but continued daratumumab with or without dexamethasone; the 60-month PFS and OS rates among this population were 97.9% and 100%, respectively, compared with 52.5% and 66.3% in the intention-to-treat population (n = 368). In patients receiving treatment for ≥18 months, PFS (HR, 0.57; 95% CI, 0.43-0.76; P <.0001) and OS (HR, 0.68; 95% CI, 0.47-0.98; P = .0379) benefits were seen with D-Rd versus Rd. In this group of patients, responses deepened over time; complete response or better was 9.2% by 6 months, 19.1% by 9 months, and 49.8% by 18 months. In addition, PFS benefit with D-Rd versus Rd was seen in patients receiving treatment for ≥9 months (PFS HR, 0.49; 95% CI, 0.38-0.62; P <.0001), and OS benefit was also significant (OS HR, 0.63; 95% CI, 0.47-0.85; P = .0025). No new safety signals were noted, and grade 3/4 hematologic treatment-emergent adverse events with D-Rd decreased over time.
Researchers concluded that continuing D-Rd treatment for ≥18 months resulted in deep clinical responses.
Source:
Moreau P, Facon T, Usmani S, et al. Treatment duration and long-term outcomes with daratumumab in transplant-ineligible newly diagnosed multiple myeloma from the phase 3 MAIA study . Oral abstract presented at: International Myeloma Foundation; August 25-27, 2022; Los Angeles, CA.