Phathom Pharmaceuticals is a commercial-stage biopharmaceutical company focused on a single drug franchise: VOQUEZNA (vonoprazan), a treatment for acid-related gastrointestinal diseases. Vonoprazan belongs to a novel class called PCABs (potassium-competitive acid blockers), which block the proton pump directly without requiring acid activation — offering faster onset and more consistent acid suppression compared to standard proton pump inhibitors (PPIs). Phathom licenses vonoprazan from Takeda under an exclusive agreement covering the U.S., Europe, and Canada, and currently sells three products in the U.S.: VOQUEZNA tablets for GERD, and two co-packaged antibiotic combinations (DUAL PAK and TRIPLE PAK) for H. pylori infections. The GERD tablet drives the vast majority of revenue. Phathom targets GERD patients who remain symptomatic on generic PPIs — the entrenched, cheap first-line standard of care — and primarily reaches them through a ~300-person sales force focused on gastroenterologists. Phathom sells through wholesale distributors to retail pharmacies, and net revenue reflects a gross-to-net discount in the 55%-65% range driven by payer rebates. Gross margins run around 87%, with costs reflecting royalties paid to Takeda and outsourced manufacturing. Operating costs are dominated by the sales force and commercial programs. Phathom's growth strategy focuses on deepening GI prescriber adoption before eventually expanding into primary care, and the company is also running a Phase 2 trial in eosinophilic esophagitis as a potential label expansion.