Long-term outcomes after cardiac transplantation in AL amyloidosis.
Authors: Spencer Lessans, Vivek Patel, Bhagirathbhai R. Dholaria, Reena Jayani, Salyka M. Sengsayadeth, Mark Wigger, Amanda Peltier, Sara Horst, Kelly Schlendorf, Rebecca Hung, Stacey Goodman, Bipin N. Savani, Adetola Kassim, Shakthi Bhaskar, Eden Biltibo, Andrew Philip Jallouk, Hasan Siddiqi, Shelton Harrell, Muhamed Baljevic, Lynn Punnoose
Journal: Journal of Clinical Oncology (2024)

7572 Background: Systemic AL amyloidosis can lead to progressive multi-organ dysfunction including advanced heart failure which may require orthotopic heart transplantation (OHT). Hematologic outcomes of AL amyloidosis post-OHT are not well described. Methods: We report outcomes for patients with AL amyloidosis with cardiac involvement post-OHT from Nov 2008 - Jun 2023 at Vanderbilt University Medical Center. Hematologic response was graded per the ISA guidelines. Results: Fourteen pts underwent OHT of whom 13 had lambda light chain disease. Three (21%) pts had isolated AL amyloidosis (AL) without myeloma (MM), while 11 (79%) also had MM: 6 with bone marrow plasma cells (BMPCs) 10-19% (AL-PCMM-10) and 5 with BMPC ≥20% (AL-PCMM-20). One each with AL-PCMM-10 and AL-PCMM-20 had lytic lesions (AL-CRAB). Median age at OHT was 55.5 yrs (range 37-74). Median time from diagnosis to OHT was 18 mo (range 3-62). Five (35%) pts had biopsy-proven extracardiac amyloid involvement. Median difference in serum free light chains at first evaluation was 70 mg/dL (range 9-289). Three pts were Mayo 2012 stage II, 4 stage III, and 7 stage IV. Four pts had t(11;14) and 1 had 1q gain. Ten (71%) pts received triplet therapy (VCd or VRd) and 3 (21%) received quadruplet therapy (Dara-VCd or Isa-VCd) pre-OHT. Six (43%) pts had autologous stem cell transplantation (ASCT); 1 pre-OHT and 5 post-OHT. Of ASCT pts, 1 pt achieved CHR, 1 VGPR, 2 PR, and 1 had PD pre-ASCT. Pre-OHT, 4 pts achieved CHR, 6 VGPR, 3 PR, and 1 had PD. Eleven pts (79%) received maintenance therapy post-OHT (5 proteosome inhibitors, 6 anti-CD38). At last follow-up, 8 pts were in CHR, 3 in VGPR, 1 in PR, and 2 had PD. Four (29%) pts died post-OHT: 2 from AL recurrence (1 each with AL and AL-PCMM-10), 1 from cardiac allograft vasculopathy (AL-CRAB), and 1 from renal failure (AL-CRAB). Three (21%) pts had hematologic relapse 5, 21 and 48 mo post-OHT, and of those, 2 had recurrent cardiac amyloid in graft 37 and 71 mo post-OHT. Of those with hematologic relapse, 2 had AL-PCMM-10 and 1 had AL. One pt had post-transplant lymphoproliferative disorder 126 mo post-OHT, requiring treatment. Median follow-up and survival of the cohort post-OHT was 2.25 yrs (range 0.5-13.8). Conclusions: In this single-center analysis of pts undergoing OHT for cardiac AL amyloidosis, we demonstrate feasibility of excellent long-term outcomes, in predominantly high-risk AL pts where majority harbored high-risk disease with MM overlap, either by AL-CRAB or AL-BMPC. Induction alone led to ≥VGPR response in 10 (71%) pts pre-OHT and further therapy deepened this to 11 (79%) pts. Both AL-CRAB pts died during follow-up, highlighting the overall poor prognosis in this specific subgroup. In our cohort, non-relapse related mortality was seen in only 2 (14%) pts, demonstrating acceptable post-OHT risk and overall ability to achieve far improved outcomes in the high-risk cardiac AL amyloidosis patient population that otherwise suffers from rapid and universal mortality.