Novartis announced Tuesday that its orphan drug Signifor LAR (pasireotide) has been approved by FDA for use in acromegaly, a potentially life-threatening endocrine disorder caused by elevated growth hormone levels. This marks the 15th orphan drug approved by FDA this year—the most rare-disease drug approvals since the Orphan Drug Act was implemented in 1983.  

Pasireotide was originally approved for Cushing’s disease in 2012 under the trade name Signifor. Signifor LA was approved by EU regulators in November.

Today’s approval adds to a growing body of evidence that rare diseases are becoming the fastest-growing segments in the industry. A record-setting 260 orphan drug designations were granted in the US for 2013,  according to EvaluatePharma’s recent Orphan Drug Report. Rare-disease treatments could account for $176 billion in sales by 2020, or 19% of all prescription drug sales, the report added.

“Although orphan populations are by definition the smallest, they represent big per-patient outlays, and insurers will be looking carefully at new tools to arrest cost growth as more and more orphan drugs launch,” Anthony Raeside, EvaluatePharma’s head of research, said at the time.