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].

Group 1: Tezspire Approval and Clinical Results - AstraZeneca and Amgen's Tezspire has been recommended for approval in the EU for adult patients with chronic rhinosinusitis with nasal polyps based on the WAYPOINT Phase 3 trial results [1][3] - In the WAYPOINT trial, Tezspire showed a statistically significant reduction in nasal polyp severity, with a Nasal Polyp Score reduction of -2.08 and nasal congestion reduction of -1.04 at week 52 compared to placebo [2] - Tezspire also demonstrated a near-complete elimination of the need for surgery (98%) and a significant reduction in the need for systemic corticosteroid treatment (89%) compared to placebo [2] Group 2: Koselugo Approval and Clinical Results - The CHMP recommended approving Koselugo for symptomatic, inoperable plexiform neurofibromas in adult patients with neurofibromatosis type 1 based on the KOMET Phase 3 trial results [4] - Koselugo showed a statistically significant objective response rate of 20% compared to 5% with placebo by cycle 16 in the primary analysis of the trial [4] - The safety profile of Koselugo in the KOMET trial was consistent with its known profile and established use in pediatric patients [5] Group 3: Market Reaction - AstraZeneca's stock increased by 1.78% to $77.64, while Amgen's stock decreased slightly to $295.28 at the time of publication [5]