FDA accelerates approval of Novartis’ Scemblix for first-line leukemia treatment

Novartis’ Scemblix (asciminib) has been granted accelerated approval by the US FDA for treating adult patients newly diagnosed with Philadelphia chromosome-positive myeloid leukemia in chronic phase (Ph+ CML-CP). This approval is founded on the results from the ASC4FIRST phase 3 clinical trial, which compared Scemblix to other standard treatments for this condition. At the 48-week mark, Scemblix showed superior rates of major molecular response and fewer adverse reactions compared to other standard drugs such as imatinib, nilotinib, dasatinib, and bosutinib.

The common treatments for chronic myeloid leukemia fall under a class of drugs known as tyrosine kinase inhibitors (TKIs). While TKIs have significantly improved the management of CML, they come with safety concerns and varied patient responses. Notably, nearly half of the patients do not achieve the desired efficacy targets, and around 25% either discontinue or change their treatment within a year.

Lee Greenberger, Chief Scientific Officer at The Leukemia & Lymphoma Society, emphasized the challenges faced by patients newly diagnosed with CML. He noted that side effects often disrupt daily life, leading patients to switch or stop treatment. He highlighted the importance of new first-line treatment options, as finding suitable medication early in treatment could result in better disease control and fewer side effects.

Previously, in 2021, Scemblix received FDA approval for patients with Ph+ CML-CP who had been treated with two or more TKIs and for those with the T315I mutation. Novartis states that the latest approval significantly increases the number of patients eligible for Scemblix, expanding the patient population by approximately fourfold.

Jorge Cortes, Director of the Georgia Cancer Center, commented on the range of effective TKIs available for newly diagnosed patients. He pointed out that clinicians often had to compromise between efficacy and tolerability. However, the ASC4FIRST trial has shown that Scemblix performs well in terms of efficacy, safety, and tolerability compared to other standard TKIs. Cortes suggested that the data from Scemblix might reshape clinical practice.

The ASC4FIRST trial is still ongoing, with further data expected after 96 weeks of treatment. Continued approval of Scemblix for first-line treatment of Ph+ CML-CP will depend on additional data from this study.