The U.S. Food and Drug Administration has awarded orphan drug designation to pembrolizumab, known commercially as Keytruda, for use in treating neuroendocrine prostate cancer. The agency granted the designation on June 6.
Orphan drug designation is reserved for treatments targeting rare diseases that affect fewer than 200,000 people in the United States. The designation is intended to encourage development of therapies for these small patient populations by providing developers with specific regulatory and financial incentives.
One of the principal incentives associated with orphan designation is potential market exclusivity. If a drug that has received orphan designation later secures FDA approval for the rare-disease indication, it is entitled to seven years of market exclusivity for that indication.
At present, pembrolizumab has not received FDA approval for the treatment of neuroendocrine prostate cancer. Merck is actively studying pembrolizumab in clinical trials focused on this cancer type, with those trials typically targeting patients who are heavily pre-treated or who have metastatic disease.
The company’s ongoing investigations are intended to evaluate pembrolizumab’s safety and efficacy in the neuroendocrine prostate cancer setting. The orphan designation does not equate to approval; rather, it provides a regulatory pathway intended to help advance development for a condition that meets the statutory definition of rarity.
Given the specifics of the designation and Merck’s clinical program, stakeholders in the pharmaceutical and broader healthcare sectors will monitor the progress of the trials and any subsequent regulatory submissions that might seek approval for the neuroendocrine prostate cancer indication.
Context and next steps
Merck’s pembrolizumab remains under clinical evaluation for neuroendocrine prostate cancer. The orphan designation could affect development incentives and regulatory timelines if the company pursues approval for this particular indication, but no approval has been granted to date.