Zejula (Niraparib): The 2029-2038 Generic Opportunity Window

Zejula (niraparib tosylate monohydrate), GlaxoSmithKline's oral poly(ADP-ribose) polymerase (PARP-1/2) inhibitor for ovarian and peritoneal cancer maintenance, generated 673 million GBP (~$850M+ USD) in 2024 revenue. The primary FDA Orange Book salt patent (US 8,436,185) expires on April 24, 2029 (~2.5 years in the future relative to October 13, 2026), and core substance patent US 8,071,623 extends to March 27, 2031. Secondary formulation and crystal form patents create an intellectual property perimeter extending through March 27, 2038. Commercial status: 100% Brand-only in the United States today; zero generic niraparib is commercially approved or selling in the US. Major Indian generic pharmaceutical manufacturers (including Natco, Sun Pharma, Cipla, and Dr. Reddy's) are actively positioned in API synthesis and Paragraph IV ANDA filings targeting the post-2029 launch window.