FLAG-IDA + venetoclax in newly diagnosed (ND) or relapsed/refractory (RR) AML.

6519 Background: We report the outcomes of a phase 2 study of FLAG-IDA+VEN in AML. Methods: Pts ≥18 with ND or RR AML / MDS-EB2 fit for intensive chemotherapy were eligible. Induction comprised fludarabine 30mg/m 2 D2–6, cytarabine 1.5g/m 2 D2–6, idarubicin 8 (6 if RR) mg/m 2 D4–6 following a protocol modification, VEN is now administered D1–7. The primary outcome was ORR (CR + CRh + CRi + MLFS + PR). Secondary outcomes were CRc (CR + CRh + CRi), overall survival (OS), event-free survival (EFS) 19 (15%) age ≥60. 13 (19%), 22 (32%) & 33 (49%) ND pts were ELN22 favorable, intermediate & adverse respectively. There were 7 (10%) secondary (s), including 4 hypomethylating agent failure, & 7 (10%) therapy-related (t) AML. In RR pts, 40 (68%) were in salvage 1 (S1), of whom 32 (54%) were TP53 WT . 20 (34%) had prior stem cell transplant (SCT). Median of 2 cycles were given. In ND pts, ORR was 99%, (96% CRc, of whom 89% MRD negative Table). Similar responses were seen across ELN groups & s/tAML. At median follow-up (mFU) of 30 months (mo), the mOS, mEFS & mDOR were not reached. The 2yr OS, EFS & DOR were 75% (64 – 88), 68% (56 – 81) & 71% (59 – 85) respectively, with no differences among ELN groups. 57% went to SCT in CR1. 4/4 pts with TP53 mut became CRc MRD–, but mDOR was only 8.2 mo (95% CI, 2.2 – NE), resulting in poor mOS (13.5 mo, 95% CI, 8.6 – NE). In RR pts, ORR was 70% (66% CRc, of whom 79% MRD negative Table). At mFU 27 mo, the mOS, mEFS & mDOR were 12 (7 – 33), 7 (4 – 23) & 21 (8 – NE) mo respectively. The 2yr OS, EFS & DOR were 40% (28 – 55), 34% (23 – 49) & 49% (35 – 68) respectively. 58% went to SCT. S1+ TP53 WT pts had mOS of 34 mo (12 – NE), with 72% going to SCT. 30d & 60d mortality were 0% & 3%. Of the 4 deaths within 60d, 1 was sepsis-related in CR in a ND pt while 3 were disease-related in NR RR pts. The most frequent adverse event was infection. Grade ≥3 infections, gastrointestinal toxicities & bleeding occurred in 102 (80%), 20 (16%) & 9 (7%) pts respectively. The median time to neutrophil >1x10 9 /L & platelet >50x10 9 /L were 27d & 28d for C1, 39d & 67d for C2 & 35d & 50d for C3 respectively. Conclusions: FLAG-IDA+VEN results in high MRD negative response rates, leading to impressive survival outcomes across ELN risk groups in ND AML. It is an effective salvage regimen for RR AML, especially for S1+ TP53 WT pts. Clinical trial information: NCT03214562 . Table: see text