Within the past few years, the FDA has been approving an increasing number of specialty medications. Fourteen specialty medications were approved in the first three quarters of 2011, which matches the total number of specialty drugs approved in 2010. This is up from 10 specialty drug approvals in 2009 and 8 in 2008.
Based on an analysis of the specialty pipeline, 2012 is shaping up to be a significant year for specialty drug approvals. By the end of next year, it is possible that 3 new oral, disease-modifying drugs for multiple sclerosis (MS) will be available. It is also anticipated that the FDA will approve the first oral alternative to injectable therapies for rheumatoid arthritis (RA). In addition, several new cancer drugs are expected to gain FDA approval and new drugs for cystic fibrosis (CF) may hit the market. More information about selected specialty pipeline medications can be found in this article.
Dimethyl fumarate (BG-12) is an oral, disease-modifying medication in development for the treatment of MS. BG-12 is effective in reducing relapse rates in patients with relapsing remitting MS. According to a clinical study, BG-12 reduced annualized relapse rates by 53%. Key side effects associated with BG-12 use include gastrointestinal intolerance and flushing. Results from a pivotal trial comparing BG-12 to Copaxone (glatiramer acetate, Teva) are expected in the fourth quarter of 2011. Beginning next year, BG-12 will likely compete with Gilenya (fingolimod, Novartis)—the first oral disease-modifying drug approved for MS—as well as injectable therapies currently on the market for MS.
Tofacitinib is a novel immunosuppressant known as a JAK (or Janus-Associated Kinase) inhibitor that primarily inhibits the JAK-3 pathway, which is responsible for causing an inflammatory response. It is in development to treat moderately-to-severely active RA. Tofacitinib is an oral tablet taken twice daily. Its efficacy for RA is on par with the tumor necrosis factor (TNF) inhibitors (eg, Enbrel [etanercept, Amgen/Pfizer], Humira [adalimumab, Abbott]) so there is a potential for use in the first-line setting. Safety concerns associated with the use of tofacitinib include increases in cholesterol and liver enzymes and decreases in white blood cells counts that can potentially lead to infection. Pfizer is expected to file for approval of tofacitinib by the end of 2011, with approval likely in mid-2012.
Ruxolitinib is an example of another JAK inhibitor that primarily inhibits the JAK-2 pathway that is involved with the formation and development of blood cells. It is being developed to treat myelofibrosis, which is an uncommon, life-threatening blood cancer characterized by bone marrow failure, enlarged spleen, poor quality of life, and shortened survival. Approximately 30,000 patients in the United States have myleofibrosis. Other than allogenic stem cell transplantation, there are no approved treatment options. Ruxolitinib is an oral tablet that is taken twice daily. Incyte filed for approval of ruxolitinib in June 2011 and the FDA approval is expected in early December 2011.
Vismodegib is another novel, oral cancer medication in the pipeline. It is known as a hedgehog pathway inhibitor that is in development for the treatment of patients with advanced basal cell carcinoma (BCC) who are not candidates for surgery. Vismodegib is an oral medication that is taken once daily. BCC is the most common type of skin cancer with approximately 800,000 cases diagnosed each year in the United States. Only a small subset of those patients will be candidates for treatment with vismodegib since the majority of BCC cases can be removed with surgery. Genentech filed for approval of vismodegib in September 2011. If priority (6-month) review is granted, vismodegib may receive FDA approval in the first quarter of 2012.
VX-770 is a chloride channel activator that increases mucus clearance in patients with cystic fibrosis. CF is a life-threatening genetic disease that affects approximately 30,000 patients in the United States. It is caused by a defective gene that results in the build-up of abnormally thick, sticky mucus in the lungs and pancreas causing serious lung infections and digestive problems. VX-770 treats the underlying disease of CF; it is most effective in patients in whom the G551D mutation is primarily responsible for causing the chloride transport defect that results in increased mucus production. Approximately 4% of patients with CF have at least 1 copy of the G551D mutation. VX-770 is an oral tablet formulation that is taken twice daily. VX-770 may reach the market by the end of 2012. Several other medications for CF may also reach the market within the next 2 years.
Dr. Tharaldson is senior clinical consultant, Emerging Therapeutics, at Express Scripts.