AZN Wins FDA Nod for Expanded Use of Rare Disease Drug, Koselugo

Core Insights - AstraZeneca (AZN) received FDA approval for the expanded use of its oral selective MEK inhibitor, Koselugo (selumetinib), to treat symptomatic, inoperable plexiform neurofibromas (PN) in adult patients with neurofibromatosis type 1 (NF1) in the United States [2][6]. Regulatory Approvals - Koselugo's label has been expanded in the EU, Japan, and other countries, with ongoing regulatory reviews [3][6]. - A granule formulation of Koselugo was also approved by the FDA for young children aged one year and older with NF1 PN [3]. Clinical Study Results - The FDA's approval was supported by data from the global phase III KOMET study, which showed a statistically significant overall response rate (ORR) of 20% for Koselugo compared to 5% for placebo by cycle 16 [4][6]. - Approximately 86% of patients receiving Koselugo achieved a duration of response of at least 6 months [5]. Market Performance - Year to date, AstraZeneca's shares have increased by 35.3%, outperforming the industry growth of 15.8% [5]. Disease Background - NF1 is a rare genetic disorder that can lead to the development of non-cancerous PN, affecting multiple organ systems and potentially causing significant health issues [7]. Collaboration and Financials - AstraZeneca has modified its partnership with Merck regarding Koselugo, assuming full global responsibility for the drug's costs, revenues, and profits [9].