PTC Therapeutics was one of the first pharmaceutical companies to develop a treatment for Duchenne muscular dystrophy (DMD). Developing ataluren (Translarna™), a treatment that works on a nonsense mutation in the dystrophin gene took 20 years. When PTC started its research, there was no North Star Ambulatory Assessment (NSAA), a mobility test that measures the results of treatment. The company began with a blank sheet. Its hard work and persistence encouraged other pharmaceutical companies to jump in and investigate new treatments for DMD.
Dedicated to making a difference
PTC Therapeutics is very dedicated to the DMD community. It’s never given up the fight, despite the hurdles in developing DMD therapies. In the words of Stuart W. Peltz, CEO, since day one, the company has felt that it’s part of our cause:
“Working in diseases like Duchenne muscular dystrophy, oncology, and spinal muscular atrophy positions you right in front of the patients and their families. You have the opportunity to understand the challenges that these families face every day. The possibility of leading the team that tries to discover drugs that alter the course of these diseases and hopefully change the lives of these patients gives our work incredible purpose; it inspires and motivates all of us at PTC. It helps everyone understand why we are always so persistent; every day matters to the patients and their families. It makes PTC a cause as much as a company.”
Two treatments for DMD
PTC Therapeutics has developed two treatments for DMD: ataluren (Translarna™) and deflazacort (Emflaza®), a corticosteroid. Ataluren is in clinical development for patients with a nonsense mutation in the dystrophin gene (nonsense mutation Duchenne muscular dystrophy or nmDMD). It has been approved by the European Union for ambulatory patients with nmDMD who are 5 years and older.
What is a nonsense mutation?
DMD is a devastating disease that is caused by mutations in the dystrophin gene. The mutations vary in nature and account for the deletion, faulty replication, or duplication of parts of the genetic blueprint or code for protein manufacture. In other words, mutations in the dystrophin gene disrupt the ways in which protein factories in cells read its genetic code while making the dystrophin protein. The result is the absence of functional dystrophin protein in skeletal and cardiac muscles.
A change in a single base (point) of DNA can prematurely end the translation of a gene into a protein. About 10 % to 15 % of single-point mutations are nonsense mutations. They occur during the translation of messenger RNA (mRNA), which copies the genetic code during the manufacturing process, into protein.
The U.S. drug approval process
In September 2017, the U.S. Food and Drug Administration (FDA) held an AdCom meeting to evaluate the effects of ataluren. Unfortunately, the FDA response on October 25, 2017, declared that clinical data for the benefits of ataluren was inconclusive. PTC Therapeutics has reassured U.S. families, currently enrolled in several clinical trial extension programs, that they will continue to receive ataluren. The company has filed an appeal for dispute resolution. It will make a final decision about the distribution of ataluren in the USA after the outcome. For Canadian families, there is no information to suggest any change in distribution.
Ataluren in Canada
At this moment, PTC Therapeutics has not filed an application for marketing approval with Health Canada, but it has started a conversation with the legislator.
The second treatment for DMD in PTC Therapeutics’ portfolio is approved in the USA for use in patients with nmDMD who are ambulatory and 5 years and older. In Canada, eligible patients can ask to receive deflazacort through a Special Access Program (SAP). This Health Canada program enables doctors to prescribe a drug not approved for sale or distribution in Canada to patients with a serious or life-threatening disease that has no other viable treatment.
Learn more about nonsense mutation: here
Learn more about ataluren (Translarna™) at www.ptcbio.com
Learn more about Emflaza® at www.emflaza.com