Enliven Therapeutics released new Phase 1 data for its chronic myeloid leukemia program (CML) it hopes can eventually compete with Novartis’ Scemblix.
The experimental therapy, called ELVN-001, was tested in 39 patients across multiple dose levels, and 18 were evaluable for efficacy at the cutoff. After 24 weeks, Enliven said 44% of those patients saw a “cumulative major molecular response” (MMR). Response rates were similar among patients who were resistant to tyrosine kinase inhibitors and those previously treated with Scemblix.
That’s a small, early snapshot, but if responses persist, data show the drug could provide CML patients with more treatment options. CML’s chronic nature makes it difficult to treat — Novartis estimates that as many as 50% of patients don’t meet their MMR goals and as many as 25% switch TKIs in the first year of treatment.
Enliven’s patient population embodied those challenges: 27 of 39 patients had received at least three prior TKIs, and 10 received at least five. In addition, 21 had previously taken Scemblix and 27 previously discontinued their most recent TKI due to a lack of efficacy, Enliven said.
Approved in 2021, Scemblix was the first third-generation drug available for CML patients, and is designed to target the same mutation as ELVN-001. Novartis CEO Vas Narasimhan previously said Scemblix was one of his “wild card” drugs, representing a high-risk, high-reward payoff.
Mizuho analyst Salim Syed wrote in a note on Monday that Enliven’s results are a win for the company. He said that the 44% MMR after 24 weeks held up from previous results, when Enliven reported the same rate at their 12-week interval earlier this year.
There was also no cardiovascular toxicity reported, which was “arguably the more important piece of the dataset,” Syed wrote, because most heart-related side effects start to manifest after 24 weeks for patients taking TKIs.
TD Cowen analyst Phil Nadeau noted that ELVN-001’s MMR is competitive with other Phase 1 data from recently approved drugs like Scemblix (37% at 24 weeks) and Pfizer’s Bosulif (15% at 28.5 months). He cautioned that there are limitations to comparing results across trials, however.
ELVN-001 is a small molecule kinase inhibitor designed to target the BCR-ABL gene fusion, which researchers believe is a major driver of CML. Enliven says the drug can also protect against one of the most common gene mutations, T315I, that arises in patients who take TKI drugs to treat their disease.
Additional data from the study are expected next year with follow-up from between 60 and 100 patients. Enliven has said it is also looking at a head-to-head trial against Scemblix, and is talking to the FDA.
Editor’s note: This story incorrectly said that Enliven expected to have its head-to-head trial cleared by the FDA by the end of next year. It is still in conversation with regulators about a trial.