Sorafenib plus 5-azacytidine (AZA) in older untreated FLT3-ITD mutated AML.

Abstract

7029 Background: Sorafenib plus 5-azacytidine (AZA) is observed to be safe and effective in relapsed / refractory FLT3-ITD mutated acute myeloid leukemia (AML) patients (pts). Hypothesis: Combining sorafenib with AZA is safe and effective in older untreated FLT3-ITD mutated AML pts. Methods: Eligibility included: untreated FLT3-ITD mutated AML (≥10% mutation burden), age ≥60 yrs, adequate organ function, and ECOG performance status ≤ 2. The regimen was: AZA 75 mg/m2daily x 7 days and sorafenib 400 mg twice daily for 28 days. Results: 26 pts with untreated AML [median age 73 (61-86)] were enrolled: 16 (62%) pts had normal karyotype, 2 (8%) complex karyotype, 4 (15%) other miscellaneous abnormalities, and 4 (15%) with insufficient metaphases. Prior to the initiation of treatment, FLT3-ITD was detected in all pts with a median allelic ratio of 0.3735 (0.009-0.885). The overall response rate (ORR) in 25 evaluable pts was (76%) [7 (28%) with CR, 10 (40%) CRi/CRp, and 2 (8%) PR]. Pts underwent a median of 3 (1-35) treatment cycles. The median number of cycles to response was 2 (1-4), and the median time to achieve response, 1.77 months (mos) (0.689-4.271 mos). The median duration of CR/CRp/CRi is 14.5 mos (1.18—28.74). Three (18%) responding pts (CR, CRp, CRi) have proceeded to allogeneic stem cell transplant. With a median follow-up of 6.8 mos (0.2-18.8), 6 pts are alive, 3 in remission (CR/CRP/CRi). The median overall survival (OS) for the entire group is 8.3 mos; 9.2 mos in 17 responders. Evaluable pts treated with AZA + sorafenib (n = 25) were compared to a matched cohort of historical FLT3-ITD mutated pts > 60 yrs, but treated with hypomethylator-based (HMA) therapy without sorafenib (n = 20); the respective ORR (CR, CRp, CRi, PR) (76% vs. 70%, p = 0.653) and median OS (8.3 and 9.4 mos, p = 0.69) were similar. The remission duration for the responding pts treated with AZA+sorafenib was significantly longer (14.5 mos) than those on other HMA regimens without sorafenib (3.8 mos) (p = 0.01). Adverse events possibly attributable to the regimen included: grade (Gr) 1/2 nausea (n = 3), Gr 1/2 diarrhea (n = 2), Gr 1 dyspnea (n = 1), and Gr 1 breast pain (n = 1). Conclusions: The combination of AZA and Sorafenib is both well tolerated and effective in older untreated FLT3-ITD mutated AML. Clinical trial information: NCT02196857;NCT01254890.