Outcomes By Cardiac Stage in Newly Diagnosed AL Amyloidosis: Results from Andromeda

Background: The extent of cardiac involvement has a major impact on clinical outcomes in patients with newly diagnosed light chain (AL) amyloidosis. Here, we present the hematologic responses, major organ deterioration progression-free survival (MOD-PFS) and event-free survival (MOD-EFS), and organ responses by cardiac stage in patients with newly diagnosed AL amyloidosis treated with cyclophosphamide, bortezomib, and dexamethasone (VCd) with or without daratumumab subcutaneous (DARA SC) in the ANDROMEDA trial (NCT03201965).

Methods: Key eligibility criteria included newly diagnosed AL amyloidosis with measurable hematologic disease, ≥1 involved organ, cardiac stage I-IIIA (based on the European Modification of the Mayo staging system), eGFR ≥20 mL/min, and absence of symptomatic multiple myeloma. Patients were randomized (1:1) to receive DARA-VCd or VCd alone. All patients received bortezomib (1.3 mg/m² SC weekly), cyclophosphamide (300 mg/m² oral [PO] or intravenous [IV] weekly [500 mg maximum]), and dexamethasone (20-40 mg PO or IV weekly) for six 28-day cycles. DARA SC (1800 mg, co-formulated with recombinant human hyaluronidase PH20 in 15 mL) was administered by injection weekly in Cycles 1-2, every 2 weeks in Cycles 3-6, and every 4 weeks thereafter for up to 24 cycles. Disease evaluations occurred every 4 weeks (Cycles 1-6) and every 8 weeks (after Cycle 7) until major organ deterioration, hematologic progression, death, end of study, or withdrawal. The primary endpoint was overall (ie, at any time) hematologic complete response (CR) rate. Secondary endpoints included MOD-PFS, MOD-EFS, organ response rate, time to hematologic response, survival, and safety. Analyses of hematologic CR and MOD-PFS were performed on the intent-to-treat analysis set; cardiac response analyses were based on patients who were evaluable for cardiac response, defined as patients with baseline NT-ProNBP value ≥650 ng/L or baseline NYHA class 3 or 4 and received at least 1 administration of study treatment. Patients without a baseline assessment or post-baseline assessment were censored at randomization for the MOD-PFS analysis. Descriptive statistics were used to summarize overall CR rate and organ response rate. Hazard ratios and corresponding 95% confidence intervals were estimated based on Cox proportional hazard model.

Results: A total of 388 patients were randomized to receive DARA-VCd (n=195) or VCd alone (n=193). Baseline characteristics were well balanced between treatment groups. The median age was 64 years and the proportions of patients with cardiac stage I, II, and III were 23%, 40%, and 37%, respectively. The median duration of treatment was 9.6 months for DARA-VCd and 5.3 months for VCd. Median follow-up was 11.4 months (range, 0.03-21.3+). Baseline characteristics were generally balanced across cardiac stages, except increasing cardiac stage was associated with older age (≥65 years), worse Eastern Cooperative Oncology Group performance status, more advanced renal failure (CrCl ≤30), and functionally worse heart failure (NYHA IIIA). Hematologic CR rates were higher in the DARA-VCd group than in the VCd group in patients with cardiac stages I, II, and III at baseline (Table). Cardiac and renal response rates at 6 months were also higher in the DARA-VCd group regardless of cardiac stage at baseline (Table). The hazard ratios (HRs) for MOD-PFS were 0.33, 0.55 and 0.66 for cardiac stages I, II and III, respectively, favoring DARA-VCd. Corresponding HRs for MOD-EFS were 0.24, 0.39, and 0.48, respectively. Rates of any grade adverse events (AEs) were similar in patients with and without cardiac involvement at baseline. Across both treatment arms, rates of serious treatment-emergent AEs were higher in patients with cardiac involvement at baseline than in those without.

Conclusions: The benefit of DARA-VCd was retained over VCd alone across cardiac stages for hematologic CR, MOD-PFS, MOD-EFS, and organ responses.