Scemblix shows superior major molecular response (MMR) rates vs. standard-of-care TKIs in Phase III trial for newly diagnosed patients with chronic myeloid leukemia

ASC4FIRST is the first and only randomized head-to-head Phase III trial comparing a CML treatment vs. approved standard-of-care first- and second-generation TKIs.

The trial met both primary endpoints of major molecular response (MMR) rate for Scemblix compared to investigator-selected TKIs (imatinib, nilotinib, dasatinib, and bosutinib) and compared to imatinib, demonstrating clinically meaningful and statistically significant results for both endpoints. Scemblix showed a favorable safety and tolerability profile with fewer adverse events (AEs) and treatment discontinuations vs. investigator selected standard-of-care TKIs. The ASC4FIRST data showed no new safety signals compared to the established safety profile of Scemblix.

“We are very encouraged by these results given that a significant proportion of patients with newly diagnosed chronic myeloid leukemia, or CML, do not achieve their treatment goals,” said Prof. Tim Hughes, MD, South Australian Health & Medical Research Institute (SAHMRI). “There remains a significant need in first-line therapy of CML for tolerable treatment options, allowing people with CML to balance their treatment alongside their quality of life.”

Improvements in treatment have transformed CML into a chronic disease, with a life expectancy similar to that of the general population, making tolerability an important treatment goal. While many patients with CML may benefit from available TKI therapy, intolerance and AEs remain a primary reason for TKI therapy discontinuation, with discontinuation rates due to AEs of up to 25% by five years. Additionally, over 60% of newly diagnosed CML patients fail to meet 12-month molecular response goals.

“We are excited that Scemblix may help people newly diagnosed with CML achieve their treatment goals while continuing to live their lives,” said Shreeram Aradhye, M.D., President, Development and Chief Medical Officer, Novartis. “Given the chronic nature of their condition, patients often need to be on TKI therapy for many years, so treatment options that are well tolerated and highly efficacious are crucial to support adherence. This study outcome builds on our 20-year legacy in CML innovation as we strive to continue to address the remaining unmet needs for people living with this blood cancer.”

The trial remains ongoing, with the next scheduled data readout planned for week 96, which will evaluate the key secondary endpoint (MMR at week 96) as well as additional secondary endpoints.Details will be presented at an upcoming medical conference and included as part of regulatory submissions in 2024.

About ASC4FIRST Phase III Clinical Trial: ASC4FIRST (NCT04971226) is a Phase III, head-to-head, multi-center, open-label, randomized study of oral Scemblix 80 mg QD versus investigator-selected first- or second-generation TKI (imatinib, nilotinib, dasatinib, or bosutinib) in 405 adult patients with newly diagnosed Ph+ CML-CP1. The two primary endpoints of the study are to compare efficacy of asciminib vs. investigator-selected TKI and to compare efficacy vs that of TKI within the stratum of participants with imatinib as pre-randomization selected TKI, based on proportion of patients that achieve MMR at week 481. The study remains ongoing with a key secondary endpoint of proportion of patients that achieve MMR at week 96 and a safety endpoint of discontinuation of study treatment due to an AE (TTDAE) by week 96. The study also assesses additional secondary safety and efficacy endpoints, including MMR, MR4, MR4., complete hematological response (CHR) and BCR::ABL1 less than 1% at and by all scheduled data collection time points; duration of and time to first MMR, MR4 and MR4.; time to treatment failure; event-free survival, failure-free survival, progression-free survival, and overall survival.