Merck & Co Q1 2026 Results — Sales Growth, Regulatory Approvals and Clinical Milestones

Financial results

Total Q1 sales $16.3B (5% growth; 3% ex‑FX); KEYTRUDA $8.0B, WINREVAIR $525M, Animal Health $1.8B. GAAP loss per share $1.72 and non‑GAAP loss per share $1.28, each including a $3.62/share ($9.0B) charge for the acquisition of Cidara.

Expenses and tax

SG&A $2.7B; R&D $12.6B (vs $3.6B) driven primarily by the $9.0B Cidara charge, higher clinical spend and restructuring; GAAP gross margin 74.2% (non‑GAAP 81.9%). Income tax provision $709M on a pretax loss, effective tax rate (20.1)% (non‑GAAP rate (43.5)% including the Cidara impact).

Regulatory and clinical milestones

FDA approved IDVYNSO for certain adults with virologically suppressed HIV‑1 and approved KEYTRUDA plus paclitaxel (with or without bevacizumab) for PD‑L1+ platinum‑resistant ovarian cancer; EC approved ENFLONSIA for infant RSV prevention; FDA approved NUMELVI for dogs. Positive Phase 3 CORALreef AddOn (enlicitide) and KEYNOTE‑B15 results reported; priority reviews and late‑stage data announced across multiple oncology programs.

Business development and outlook

Announced agreement to acquire Terns Pharmaceuticals; transaction expected to close in May and is expected to generate a one‑time charge of ~ $5.8B (~$2.35/share). Full‑year 2026 guidance narrowed to $65.8–67.0B in sales and non‑GAAP EPS $5.04–5.16; guidance includes the Cidara charge and excludes the expected Terns impact.

Other

Koselugo alliance revenue $161M in Q1, reflecting a $150M payment from AstraZeneca under a collaboration amendment; an oncology investor event is scheduled for June 1, 2026.