Viatris has announced that the US Food and Drug Administration (FDA) has issued a complete response letter (CRL) to Mapi Pharma in response to its new drug application for GA Depot 40mg to treat patients with relapsing forms of multiple sclerosis (RMS).

Viatris secured the commercialisation rights to GA Depot's injection product for relapsing forms of multiple sclerosis via an exclusive licence deal with Mapi Pharma in 2018.

Mapi Pharma and Viatris are currently assessing the CRL to determine their next steps.

In August 2023, the FDA accepted the NDA for GA Depot 40mg for review.

A long-acting injection version of the previously approved glatiramer acetate, this new product is designed for use as a once-monthly injection for RMS.

The NDA submission for the product was based on the findings from a multinational, double-blind, placebo-controlled Phase III clinical trial.

It evaluated the efficacy, safety and tolerability of GA Depot in comparison to a placebo in 1,016 RMS patients.

Subjects were randomly assigned to receive either 40mg of GA Depot or a placebo as an intramuscular injection once every four weeks for a total of 13 doses.

The study's findings suggested that GA Depot could offer a more convenient dosing schedule and potentially fewer injection site reactions than other glatiramer acetate products.

The primary endpoint was met, as GA Depot 40mg reduced the annualised relapse rate by 30.1% compared to placebo.

The receipt of the CRL does not affect Viatris' financial guidance for 2024 or its projected new product revenue of between $450m and $550m.

Viatris and Mapi believe that the product has the potential to offer a key new treatment option for MS patients.