Efficacy and safety of once-weekly and twice-weekly bortezomib in patients with relapsed systemic AL amyloidosis: results of a phase 1/2 study

AbstractThis first prospective phase 2 study of single-agent bortezomib in relapsed primary systemic AL amyloidosis evaluated the recommended (maximum planned) doses identified in phase 1 testing (1.6 mg/m2 once weekly [days 1, 8, 15, and 22; 35-day cycles]; 1.3 mg/m2 twice weekly [days 1, 4, 8, and 11; 21-day cycles]). Among all 70 patients enrolled in the study, 44% had ≥ 3 organs involved, including 73% and 56% with renal and cardiac involvement. In the 1.6 mg/m2 once-weekly and 1.3 mg/m2 twice-weekly groups, the hematologic response rate was 68.8% and 66.7% (37.5% and 24.2% complete responses, respectively); median time to first/best response was 2.1/3.2 and 0.7/1.2 months, and 78.8% and 75.5% had response durations of ≥ 1 year, respectively. One-year hematologic progression-free rates were 72.2% and 74.6%, and 1-year survival rates were 93.8% and 84.0%, respectively. Outcomes appeared similar in patients with cardiac involvement. Among all 70 patients, organ responses included 29% renal and 13% cardiac responses. Rates of grade ≥ 3 toxicities (79% vs 50%) and discontinuations/dose reductions (38%/53% vs 28%/22%) resulting from toxicities appeared higher with 1.3 mg/m2 twice-weekly versus 1.6 mg/m2 once-weekly dosing. Both bortezomib dose schedules represent active, well-tolerated regimens in relapsed AL amyloidosis. This study was registered at www.clinicaltrials.gov as #NCT00298766

Graded Cardiac Response Criteria for Patients With Systemic Light Chain Amyloidosis

PURPOSE: Binary cardiac response assessment using cardiac biomarkers is prognostic in light chain amyloidosis. Previous studies suggested four-level cardiac responses using N-terminal prohormone of brain natiuretic peptide improves prognostic prediction. This study was designed to validate graded cardiac response criteria using N-terminal prohormone of brain natiuretic peptide/brain natiuretic peptide. PATIENTS AND METHODS: This retrospective, multicenter study included patients with light chain amyloidosis who achieved at least a hematologic partial response (PR) and were evaluable for cardiac response. Four response criteria were tested on the basis of natriuretic peptide response depth: cardiac complete response (CarCR), cardiac very good partial response (CarVGPR), cardiac PR (CarPR), and cardiac no response (CarNR). Response was classified as best response and at fixed time points (6, 12, and 24 months from therapy initiation). The study primary outcome was overall survival. RESULTS: 651 patients were included. Best CarCR, CarVGPR, CarPR, and CarNR were achieved in 16%, 26.4%, 22.9%, and 34.7% of patients, respectively. Patients in cardiac stage II were more likely to achieve CarCR than patients in cardiac stage IIIA and IIIB (22% v 13.5% v 3.2%; P < .001). A deeper cardiac response was associated with a longer survival (5-year overall survival 93%, 79%, 65%, and 33% for CarCR, CarVGPR, CarPR, and CarNR, respectively; P < .001). Fixed time-point analyses and time-varying covariates Cox regression analysis, to minimize survivorship bias, affirmed the independent survival advantage of deeper cardiac responses. Four-level response performed better than two-level response as early as 12 months from therapy initiation. CONCLUSION: Graded cardiac response criteria allow better assessment of cardiac improvement compared with the traditional binary response system. The study re-emphasizes the importance of early diagnosis, which increases the likelihood of deep cardiac responses