– European Commission ratification anticipated in coming months –

– Approval of the Translarna annual re-assessment also recommended by CHMP –

SOUTH PLAINFIELD, NJ, USA I June 1, 2018 I PTC Therapeutics, Inc. (NASDAQ: PTCT) today announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has recommended approval of expanding the indication of Translarna™ (ataluren) to include ambulatory children aged two to five years with nonsense mutation Duchenne muscular dystrophy (nmDMD). This broadens the use beyond the current indication which is for ambulatory patients who are over five years of age. This recommendation is based on the CHMP’s review of PTC’s Study 030 trial results which the CHMP concluded demonstrates a positive benefit-risk ratio in this population. In addition to the label expansion, the CHMP has also recommended the renewal of the current marketing authorization of Translarna.

“Early diagnosis and treatment has been a paramount part of our strategy and this recommendation perfectly aligns with our vision of giving best-in-class treatment to patients,” said Marcio Souza, chief operating officer of PTC Therapeutics.

PTC’s focus on early patient identification and market readiness have been intensified in anticipation of the CHMP recommendation and the launch of Translarna for patients as young as 2 years of age is planned to start immediately at the time of EC ratification.

About ataluren (Translarna™)

Ataluren, discovered and developed by PTC Therapeutics, Inc., is a protein restoration therapy designed to enable the formation of a functioning protein in patients with genetic disorders caused by a nonsense mutation. A nonsense mutation is an alteration in the genetic code that prematurely halts the synthesis of an essential protein. The resulting disorder is determined by which protein cannot be expressed in its entirety and is no longer functional, such as dystrophin in Duchenne muscular dystrophy. Translarna, tradename of ataluren, is licensed in the European Economic Area for the treatment of nonsense mutation Duchenne muscular dystrophy in ambulatory patients aged five years and older. Ataluren is an investigational new drug in the United States. The development of ataluren has been supported by grants from the Muscular Dystrophy Association; FDA’s Office of Orphan Products Development; National Center for Research Resources; National Heart, Lung, and Blood Institute; and Parent Project Muscular Dystrophy.

About Duchenne Muscular Dystrophy

Primarily affecting males, Duchenne muscular dystrophy (DMD) is a rare and fatal genetic disorder that results in progressive muscle weakness from early childhood and leads to premature death in the mid-twenties due to heart and respiratory failure. It is a progressive muscle disorder caused by the lack of functional dystrophin protein. Dystrophin is critical to the structural stability of all muscles, including skeletal, diaphragm, and heart muscles. Patients with DMD can lose the ability to walk as early as age ten, followed by loss of the use of their arms. DMD patients subsequently experience life-threatening lung complications, requiring the need for ventilation support, and heart complications in their late teens and twenties. More information on the signs and symptoms of DMD can be found at: www.duchenneandyou.com

About PTC Therapeutics, Inc.

PTC is a science-led, global biopharmaceutical company focused on the discovery, development and commercialization of clinically differentiated medicines that provide benefits to patients with rare disorders. Founded 20 years ago, PTC Therapeutics has successfully launched two rare disorder products and has a global commercial footprint. This success is the foundation that drives investment in a robust pipeline of transformative medicines and our mission to provide access to best-in-class treatments for patients who have an unmet medical need.

SOURCE: PTC Therapeutics