Interim analysis (IA) of OPTIC: A dose-ranging study of three ponatinib (PON) starting doses.

Abstract

7502 Background: In PACE (NCT01207440) heavily pretreated patients (pts) with chronic-phase CML (CP-CML) had deep, lasting responses to PON; long-term follow-up showed increasing rates of arterial occlusive events (AOEs). We present IA results from OPTIC (NCT02467270), evaluating the association between PON exposure, efficacy, and safety, and response-based dose reduction in pts with CP-CML. Methods: This ongoing, multicenter, randomized phase 2 trial enrolled pts with CP-CML resistant or intolerant to ≥2 TKIs or with a T315I mutation to receive PON at a starting dose of 45 mg (cohort A), 30 mg (B), and 15 mg (C) qd. Doses were reduced to 15 mg qd on achievement of ≤1% BCR-ABL1IS in A/B. Primary endpoint: 12 mo ≤1% BCR-ABL1IS; secondary endpoints include cytogenetic and molecular response and AOE, VTE, and TEAE rates. Results are descriptive at this IA and will be inferential by adjusting multiplicity across 3 cohorts at final analysis. Results: 283 pts were randomized (A/B/C: n = 94/95/94); median age 48 y (18‒81 y). 26% had hypertension history; 2/43/55% received 1/2/≥3 TKIs; 40% had ≥1 baseline (BL) mutations, with 23% T315I. At IA data cutoff (20 Jul 2019), 162 pts (57%; n = 57/51/54) remained on study treatment. Among 282 pts in the safety population, median duration of exposure was ≈1 y (A/B/C, 12.9/11.2/11.0 mo). At 12 mo, 39% (95% CI, 27.6, 50.6), 27% (17.6, 39.1), and 26% (16.5, 38.6) in A, B, and C, respectively, achieved ≤1% BCR-ABL1IS. Additional efficacy in Table. Dose reductions due to efficacy (A/B): 35/21%. Most common TEAEs (any grade/≥3): thrombocytopenia 39/27%, neutropenia 25/17%. AOEs/serious AOEs were reported by (A, B, C) 5%/2%, 4%/3%, and 1%/0%. Dose reductions due to TEAEs: (A/B/C): 44/31/28%; discontinuations due to TEAEs: 18/15/14%. There were 4 (1.4%) on-study deaths; A, sudden death, n = 2; C, pneumonia, n = 2; no deaths were due to AOEs. Clinical trial information: NCT01207440 . Conclusions: OPTIC IA shows a trend toward dose-dependent efficacy and safety and may provide a refined understanding of the PON benefit:risk profile and its relation to dose. Data from longer follow-up may support an alternate dosing regimen for pts with CP-CML. [Table: see text]