Novartis (NYSE: NVS) announced 144-week results from the ASC4FIRST trial of Scemblix (asciminib) for newly diagnosed chronic myeloid leukemia patients at the American Society of Clinical Oncology Annual Meeting.

The trial compared Scemblix to standard-of-care tyrosine kinase inhibitors including imatinib and second-generation TKIs in adult patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase. At week 144, Scemblix achieved a major molecular response rate of 77.1% compared to 53.4% for standard-of-care TKIs.

When compared specifically to imatinib, Scemblix demonstrated a 79.2% major molecular response rate versus 47.1% for imatinib. Against second-generation TKIs, Scemblix achieved 75.0% compared to 59.8%.

More patients remained on treatment with Scemblix at the study cutoff, with 78.6% continuing therapy compared to 55.9% on standard-of-care treatments. The retention rate was 81.2% for Scemblix versus 50.0% for imatinib, and 76.0% versus 61.8% for second-generation TKIs.

"These data show asciminib continued to deliver significantly higher response rates versus the comparator TKIs and offers improved response that widens over time," said Jorge Cortes, Chief of Hematology at UAB O'Neal Cancer Center.

Safety data showed Scemblix had fewer grade 3 or higher adverse events at 49% compared to 52% for imatinib and 63% for second-generation TKIs. Discontinuation due to adverse events occurred in 6% of Scemblix patients versus 13% for imatinib and 14% for second-generation TKIs.

The most frequent adverse events with Scemblix included diarrhea, headache, fatigue, musculoskeletal pain, and rash. The results will also be presented at the European Hematology Association Congress in June.