Sanofi/Regeneron RA drug rejected in US

The FDA has rejected Sanofi/Regeneron’s latest rheumatoid arthritis drug because of concerns over manufacturing deficiencies.

Sarilumab is an interleukin-6 receptor and a blockbuster hopeful for the companies, who now face a race against time as GlaxoSmithKline and Johnson & Johnson have recently filed a rival drug, sirukumab, in the same class.

This means a decision on the GSK/J&J’s rival is likely midway through next year, giving Sanofi some time to remedy problems identified during a routine check of the factory where sarilumab is filled and finished.

Sanofi said it has submitted a plan to the FDA, and is implementing the actions to remedy the regulator’s concerns.

Positively for the companies, the Complete Response Letter from the FDA did not identify any safety or efficacy concerns about sarilumab.

If approved by the FDA, sarilumab will be marketed by Sanofi’s Genzyme unit.

Sales of sarilumab are expected to peak at around a billion dollars – and Sanofi is in need of new revenues in the long term because sales of its Lantus (insulin glargine) are under threat due to competition from cut-price biosimilar competitors.

Eli Lilly is due to launch its Lantus biosimilar, Basaglar, in the US in December, and the copycat has already been on the market in Europe for more than a year.

Sanofi unveiled strong Q3 results last week, showing net sales increased 2% compared with the same period last year, to just over $9 billion.

The increase was driven by a strong performance from Genyme, where sales grew almost 17% and its vaccines unit Sanofi Pasteur, where sales grew by more than 14%.

The FDA is due to make a decision before the end of March on Sanofi’s Dupixent (dupilumab) in eczema. Also being developed in asthma, this drug could generate peak sales of $5 billion, according to some forecasts.