Europe to withdraw PTC Therapeutics' rare muscle disorder drug

(Reuters) -PTC Therapeutics said on Thursday the European health regulator's advisory panel reaffirmed a negative opinion for its drug used to treat an inherited progressive muscle-wasting disorder, sending its shares down over 11% in extended trading.

The drug, Translarna, had received conditional approval in the European Union in 2014 to treat ambulatory children aged five years and older with Duchenne muscular dystrophy (DMD) expressing "nonsense mutation", which prematurely ends the translation of a gene into a protein.

The negative opinion issued by the Committee for Medicinal Products for Human Use (CHMP) will result in the withdrawal of the drug in Europe, the company said, adding that the European Commission will ratify the opinion and remove the drug from the market within 67 days.

"The news is unfortunate as Translarna is currently the only therapy approved for the treatment of DMD patients with nonsense mutations in the EU," TD Cowen analyst Joseph Thome said in a note.

Thome estimates Translarna revenues of $214 million in 2024.

The CHMP had issued a negative opinion in September on the renewal and conversion of the conditional authorization to full marketing authorization of Translarna.

Conditional marketing authorization of a drug allows for the marketing of medicines designed to treat life-threatening diseases that have few or no treatment options, even if comprehensive clinical data is not yet available.

Translarna is designed to boost production of a protein called dystrophin, the absence of which causes muscle weakening in patients with DMD.

The neuromuscular disease affects an estimated one in 3,500 male births worldwide, according to the National Organization for Rare Disorders.

(Reporting by Mariam Sunny in Bengaluru; Editing by Krishna Chandra Eluri, Shilpi Majumdar and Sherry Jacob-Phillips)