FDA rejects Pharming's Ruconest HAE label expansion

The FDA has rejected Pharming’s application to expand the licence of Ruconest, for a use as prophylaxis for patients with the serious rare disease hereditary angioedema (HAE).

The FDA asked Pharming to carry out an additional trial in its Complete Response Letter (CRL) rejecting the company’s filing to expand Ruconest's label to include its use as a prophylactic treatment.

In 2014 the FDA approved Ruconest as a treatment of acute HAE attacks in adult and adolescent patients. Ruconest was granted EU market authorisation in 2010 as a treatment of HAE attacks.

But Sijmen de Vries, CEO of Pharming, seemed unperturbed. He said: “We see this as a minor setback. Pharming remains committed to serving the HAE community. We will continue and have the resources to develop new innovative and more convenient administration options of Ruconest for acute treatment and prophylaxis of HAE to improve patient care as outlined in our recent capital market briefing in June.”

But the market was not convinced - shares in Pharming were down 22% on the Paris stock exchange following the announcement and were worth only around 75 euro cents each at the time of writing.

The drug is an injectable plasma-free C1-esterase inhibitor (C1-INH) proven to help treat HAE attacks, which are caused by having insufficient blood protein called C1-INH, or by having C1-INH that isn’t working properly.

HAE is a very rare and serious genetic condition that can kill. It causes oedema in parts of the body including the hands, feet, genitals, face, nose, tongue and throat, and airways can be obstructed. Patients often endure severe abdominal pain, nausea and vomiting caused by swelling in the stomach wall.

In January, the FDA said Pharming’s filing was sufficient for it to review the phase 2 results, which showed consistent efficacy and safety but the company must now carry out the additional trial.

The other drugs approved by the FDA as a prophylaxis for HAE include CSL Behring’s Haegarda, which was given the green light in June last year.

Shire’s Cinryze and Takhzyro are approved for prophylaxis to prevent HAE attacks, with Takhzyro approved for over-12s. Also, in June, the FDA expanded the licence for Cinryze as a prophylaxis for patients as young as six.

Other FDA-approved treatments for HAE attacks are CSL Behring’s Berinert and Dyax’s Kalbitor.