Venetoclax Induces Sustained Complete Responses In Refractory/Relapsed Patients With Cardiac Al Amyloidosis.

e19538 Background: Venetoclax (VEN) is an orally bioavailable small molecule inhibitor of the anti-apoptotic protein BCL-2 and has been shown to have efficacy against myeloma (MM), particularly in patients that harbor t(11;14). Approximately, 50% of AL amyloidosis patients will exhibit t(11;14) making VEN an attractive therapeutic option. Methods: We here report the results of a retrospective analysis of a monocentric series of refractory/relapsed (R/R) patients (pts) heavily pretreated with cardiac AL amyloidosis treated in a french academic center. VEN was given daily alone or in association with dexamethasone (DEX), with or without bortezomib (BTZ). Treatment was planned to be administered until progression. Results: Between February 2017 and January 2019, 7 consecutive R/R pts have been treated. All had received previous BTZ and daratumumab (DARA) containing regimen. Baseline characteristics were: median age: 72.7 years (range 40-84), Mayo Clinic stage: stage I in 2 pts, stage II in 3 and stage IIIA in 2. All patients but one had in addition to cardiac deposit, systemic involvement including kidney, joint, neurologic, gastro-intestinal tract, lymph node and muscle. All but one pts were refractory to their last treatment consisting of DARA-DEX with or without IMID. The t(11;14) translocation was present in 5 pts, absent in 1 and undetermined in 1 pts. Two pts had concomitant MM at diagnosis. Median number of previous line treatments was 4 (3-5). Five patients received VEN- BTZ- DEX as described in MM (PMID: 28847998), 1 with DEX and 1 as monotherapy. Five pts received 400 mg/d, one 200 mg/d and one 100 mg/d. Median duration of treatment was 76 days (30-713). All patients but one are still on treatment. One patient treated with 400 mg/d had a dose reduction to 100 mg/d due to grade 2 diarrhea. Four patients received at least 2 cycles and were evaluable for response. One 84 y old patient in stable disease after 1 cycle died due to influenza infection. 2 patients received only one cycle of treatment. Hematological complete response occurred in 2/4 (50%) patients, after 63 and 27 days. Interestingly, responses were sustained as the 2 responders were still on therapy after 76 and 713 days. This later patient, refractory to 2 previous lines had a cardiac and neurologic response. The 2 responding patients had proven t(11:14). Conclusions: On this limited series of heavily pretreated patients with R/R AL cardiac amyloidosis VEN used as a single agent or in combination can induce prolonged response and seems a promising drug with an acceptable safety profile in patients with t(11;14).