(PA-511) Exploration of Efficacy for Frailty-adjusted Dose-reduced Pcd Regimen in Relapsed/refractory Multiple Myeloma

Introduction: According to International Myeloma Working Group (IMWG) criteria, the efficacy and safety of reduced-dose Pcd is evaluated for the frail patients with relapsed/refractory multiple myeloma (RRMM) in re-induction therapy.

Methods:

This multicenter study enrolled 21 patients with IMWG-defined frail/unfit RRMM across four centers in Shanxi, China, from July 2022 to May 2025. Patients received reduced-dose PCd therapy, consisting of pomalidomide (2 mg/day on days 1–21), cyclophosphamide (50 mg orally every other day), and dexamethasone (10 mg/week during weeks 1–4, and 5 mg/week during weeks 5–8). Efficacy, quality of life, and adverse events (AEs) were systematically assessed.

Results:

The median age was 73 years (range, 42–88); 57.1% (12/21) were male. All patients had an ECOG performance status of ≥2 (95.2% had ≥3). At baseline, 90.5% (19/21) exhibited cytopenia (excluding anemia), 90.4% (19/21) had ISS stage III disease, 63.1% (12/19) were R-ISS stage III, 66.7% (12/18) harbored high-risk cytogenetic abnormalities, and 14.3% (3/21) presented with extramedullary soft-tissue involvement.After a median follow-up of 10.0 months (range, 0.5–24.4), the overall response rate (ORR) was 71.4%, including a 28.6% complete response (CR) rate. The median progression-free survival (PFS) was 4.0 months (95% CI, 2.3–5.7), and the median overall survival (OS) was 13.6 months (95% CI, 9.8–17.4). The most common AEs were hematologic suppression, rash, and gastrointestinal reactions; no thromboembolism, peripheral neuropathy, or severe infections occurred. Dose adjustments due to hematologic toxicity were required in 28.6% of patients. Notably, frail patients did not experience higher rates of grade ≥3 treatment-emergent AEs (TEAEs).

Conclusions: The all-oral attenuated Pcd regimen demonstrates promising efficacy and tolerability in frail RRMM patients, showing non-inferior efficacy compared to standard regimens while providing a therapeutic platform for treatment-failed patients to improve their clinical status