Early 2024 eyed for approval decision in EU on masitinib for ALS
Therapy's developer granted more time to meet new guidance from EMA
The European Medicines Agency (EMA) is now expected to issue a decision in the first months of 2024 on the conditional approval of masitinib as an add-on oral therapy for amyotrophic lateral sclerosis (ALS).
The deadline extension follows a request, seeking more time, from AB Science, the therapy’s developer, to the EMA’s Committee for Medicinal Products for Human Use, known as CHMP. AB Science had asked for additional time to address a recently implemented EMA guideline regarding product manufacturing.
The CHMP is responsible for evaluating available clinical data and issuing a scientific opinion regarding the approval of medicinal products in Europe; delaying the committee’s opinion will ultimately delay the agency’s decision on whether to approve the drug.
“Based on this updated timetable, the CHMP decision on masitinib marketing authorization in ALS is expected during the first quarter of 2024,” the company stated in a press release.
AB Science says its manufacturing process complies with new guidance
The new guidance, implemented by the EMA on July 28, is aimed at all applicants with a marketing authorization application for medications with lab-made or biological active substances. It asks all companies to review their manufacturing processes to identify and reduce the risk of nitrosamine impurities, some of which can lead to cancer.
A conventional stop-clock during a drug review — a period of time that allows applicants to respond to questions from the regulatory authority — is usually 30 days. However, the company noted that such an extension would not be sufficient to evaluate its manufacturing process concerning the risk of nitrosamine formation and make any necessary adjustments to meet the guidelines.
Thus, AB Science had requested an extension, which was accepted during this month’s CHMP session. So far, according to the company, results from its review have not shown any issues that would derail its application.
“Based on the current stage of investigations, AB Science is confident that the current manufacturing process of masitinib complies with this new EMA guidance,” the company wrote.
Masitinib is an oral therapy designed to slow disease progression by reducing the activity of certain immune cells that drive inflammation in ALS.
AB Science’s application requesting the approval of masitinib is based on data from a Phase 2/3 clinical trial (NCT02588677), called AB10015. That trial evaluated masitinib as an add-on therapy to Rilutek (riluzole), an approved ALS treatment, in 394 patients.
Final results from the trial demonstrated that treatment with a 4.5 mg/kg dose of masitinib for nearly one year significantly slowed disease progression — by 27% — in people with a so-called normal disease progression. Specifically, that means a monthly decline in the ALS Functional Rating Scale-Revised scores of less than 1.1 points.
This higher dose also resulted in slower declines in lung function and quality of life.
While no significant survival differences were observed in the overall population, a significant survival benefit was detected when only people with mild or moderate disease were included in the analysis. In that group, masitinib-treated patients lived more than two years longer than those on Rilutek alone, representing a 44% reduction in the risk of death.
Conditional approval in the EU is granted to medicines that immediately fulfill an unmet medical need — for therapies whose preliminary benefits outweigh their potential risks. If granted, masitinib will be marketed in Europe under the brand name Alsitek.
Still, because a full approval will require confirmatory clinical trials, AB Science already is conducting a global Phase 3 clinical trial (NCT03127267), called AB19001, to confirm the benefits of adding masitinib to Rilutek.
In that study, about 495 participants will be randomly assigned to take one of two daily doses of masitinib (4.5 or 6 mg/kg), or a placebo, for 48 weeks, or nearly one year. The trial’s main goal is to determine the effect of treatment on disease progression, but its impact on quality of life, lung function, muscle strength, and survival also will be assessed.