Asciminib (STAMP inhibitor; BCR::ABL1 myristoyl-pocket) beats flumatinib in 1L CML-CP on EMR/MMR and AE discontinuations (China MAIC)

Asciminib is a first-in-class STAMP BCR::ABL1 inhibitor (myristoyl-pocket binder), indirectly compared vs flumatinib (an ATP-competitive 2G TKI used mainly in China) using an anchored matching-adjusted indirect comparison (MAIC) across ASC4FIRST (Phase 3; NCT04971226) and FESTnd (Phase 3; NCT02204644), with imatinib as the common comparator. After adjustment, asciminib improved EMR at week 12 to 90.0% vs 82.1% with flumatinib (OR 1.95, 95% CI 1.05-3.73; p=0.03) and increased MMR at week 48 and 96 to 66.5% and 74.0% vs 52.6% and 61.3% (OR 1.79, 95% CI 1.17-2.75; p=0.006); discontinuations due to AEs at week 48 were lower with asciminib (5.5% vs 10.2%; RR 0.29, 95% CI 0.10-0.84; p=0.02). As a real-world benchmark, 1L bosutinib (another 2G TKI) delivered ~47% MMR at 12 months vs ~37% with imatinib in BFORE—so the adjusted 48-week MMR reported here for asciminib (66.5%) looks numerically above typical 2G-TKI ranges, while flumatinib’s 48-week MMR (52.6%) sits closer to what many 2G TKIs achieve in similar newly diagnosed populations.