Allergan plc / Merck & Co., Inc. (CGRP receptor antagonist program)

Migraine (acute treatment and prevention)

$6.8B Global migraine drugs market 2024 (~$6.81B; ~10.9% CAGR through 2030)

Disease Overview

Migraine is a chronic neurovascular disorder marked by recurrent moderate-to-severe headaches, often with nausea and sensory sensitivity. It disproportionately affects working-age women, drives substantial disability and lost productivity, and historically lacked migraine-specific preventive options beyond off-label cardiovascular and antiseizure agents.

Competitive Landscape

When Allergan licensed Merck's oral CGRP receptor antagonist program for $250M upfront in 2015, acute migraine was dominated by triptans (sumatriptan, rizatriptan, eletriptan — all generic), and prevention relied on repurposed beta-blockers, topiramate, and Allergan's own Botox (chronic migraine). The oral 'gepant' class was viewed skeptically after Merck shelved telcagepant for hepatotoxicity. The deal preceded a CGRP class explosion: Amgen/Novartis Aimovig, Lilly's Emgality, and Teva's Ajovy (CGRP monoclonal antibodies for prevention) all launched 2018–2019, plus Lundbeck/Alder's Vyepti IV in 2020. Allergan's Ubrelvy (ubrogepant) won FDA approval December 2019 as the first oral acute gepant; Qulipta (atogepant) followed September 2021 as the first oral preventive gepant. Pfizer's Nurtec ODT (rimegepant, ex-Biohaven) became the dual-indication gepant competitor following Pfizer's $11.6B Biohaven acquisition in 2022. CGRP mAbs captured ~57% of the 2024 migraine market, but oral gepants — Ubrelvy and Qulipta in particular — established a durable franchise within AbbVie post-Allergan acquisition. The Merck deal is widely regarded as one of the most accretive licensing transactions of the 2010s.