Atogepant

Atogepant (AGN-241689, MK-8031) is a potent, highly selective, orally administered small-molecule antagonist of the human calcitonin gene-related peptide (CGRP) receptor, approved by the United States Food and Drug Administration for the preventive treatment of episodic migraine (September 2021) and chronic migraine (April 2023) and marketed as Qulipta in the United States and Aquipta in the European Union. The compound emerged from a Merck medicinal chemistry program that explored spiroazaindane scaffolds as CGRP receptor antagonists, passed through Allergan following portfolio divestiture, and was advanced to registration by AbbVie after its 2020 acquisition of Allergan. Structurally, atogepant is a heavily polycyclic molecule containing four chiral centers, a 2-azaspiro[4.4]nonan-1-one (spiroazaindane) motif, a piperidine-2-one ring linked by an amide bond, and a distinctive 2,3,6-trifluorophenyl substitution pattern that confers an approximately fourfold increase in receptor affinity relative to its structural predecessor ubrogepant while improving hepatic safety over earlier gepants such as telcagepant.

In vitro, atogepant binds the cloned human CGRP receptor with a Ki of 0.015 nanomolar and the native receptor with a Ki of 0.026 nanomolar, achieving greater than 10,000-fold selectivity over adrenomedullin 1, adrenomedullin 2, and calcitonin receptors, and approximately 92-fold selectivity over the amylin 1 (AMY1) receptor. Functional antagonist potency in a human alpha-CGRP-stimulated intracellular cAMP assay is 0.026 nanomolar. Screening against 116 additional therapeutic targets identified no activity below 10 micromolar. The binding kinetics are characterized by rapid on-rate (Kon 6.7 times 10 to the eighth per molar per minute) and reversible off-rate (Koff 0.03 per minute), yielding a binding half-life of approximately 40 minutes.

The clinical development program comprises four pivotal trials. The Phase 2b/3 dose-finding study (CGP-MD-04; Goadsby et al., 2020; N = 834) demonstrated efficacy across all five dose arms (10, 30, 60 mg in the published literature; 30, 60 mg in the published literature) in episodic migraine. The Phase 3 ADVANCE trial (Ailani et al., 2021; N = 873) confirmed statistically significant reductions in mean monthly migraine days at 10 mg (least-squares mean difference from placebo, negative 1.2 days), 30 mg (negative 1.4 days), and 60 mg in the published literature (negative 1.7 days; all p less than 0.001) over 12 weeks. The Phase 3 PROGRESS trial (Pozo-Rosich et al., 2023; N = 778) extended the indication to chronic migraine, demonstrating reductions at 60 mg in the published literature (negative 1.8 days versus placebo; p = 0.0009) and 30 mg in the published literature (negative 2.4 days; p less than 0.0001). The Phase 3b ELEVATE trial (Schwedt et al., 2024; N = 313) demonstrated efficacy in patients who had failed two to four classes of conventional oral preventive treatments, with a 50 percent responder rate of 51 percent versus 18 percent on placebo. A Phase 3 head-to-head trial (TEMPLE, 2025) demonstrated superiority of atogepant 60 mg in the published literature over topiramate across all primary and secondary endpoints, including a 64.1 percent versus 39.3 percent 50 percent responder rate and significantly fewer discontinuations due to adverse events (12.1 percent versus 29.6 percent).

Pharmacokinetics are characterized by rapid oral absorption (time to maximum concentration approximately 2 hours), an elimination half-life of approximately 11 hours supporting once-daily dosing, an apparent volume of distribution of 292 liters, and approximately 95.3 percent plasma protein binding. Metabolism is primarily through CYP3A4-mediated oxidation, with 42 percent of the dose excreted unchanged in feces and 5 percent in urine. The compound is a substrate for OATP1B1, OATP1B3, breast cancer resistance protein, and P-glycoprotein transporters; strong CYP3A4 inhibitors increase exposure approximately 5.5-fold, necessitating dose reduction. The principal treatment-emergent adverse events in pooled clinical trial data are constipation (6.1 percent), nausea (6.6 percent), upper respiratory tract infection (5.3 percent), and fatigue, with dose-dependent weight loss observed at higher doses. Hepatotoxicity is rare and clinically insignificant; no cases meeting Hy's law criteria have been reported, a marked improvement over the earlier gepant telcagepant. Long-term safety data extending to 156 weeks in 1,662 participants confirm a stable adverse-event profile with no new safety signals. This monograph reviews the chemistry, receptor pharmacology, pharmacokinetics, preclinical models, clinical evidence base, sourcing, handling, drug interactions, adverse events, and a comparative assessment of five CGRP-targeting alternatives against atogepant on five competency standards.