Phathom Pharmaceuticals (PHAT) investor relations material

Commercial performance and outlook

• FY revenue guidance of $310M-$325M vs. $175M last year; management cited ~70% growth in the third commercialization year.

• Positive cash flow achieved over the prior two quarters; operating profitability reached excluding stock comp, with the recent quarter close to breakeven including stock comp.

• 2027 guidance expected with the Q4 earnings call; new patient starts remain solid, while increased BlinkRx use is expected to gradually support access and persistence over multiple quarters.

Prescriber growth and market opportunity

• GI focus covers ~24,000 gastroenterologists and associated APPs; 75% of scripts come from GI, which receives 70% of sales calls.

• Q3 volume was 380,000 TRX fills, including 250,000-300,000 from GI; GI prescribing represents a >1M annualized run rate against 20M annual PPI and H2 blocker scripts, or ~5% of the opportunity.

• Management sees 20%-30% GI penetration as supporting >$1B in revenue; primary care could provide a second billion-dollar opportunity over time.

• Over the next 1-2 years, growth is expected from deeper GI use and new primary care prescribers; primary care is expected to become a larger portion over time.

• GI use is expanding from severe to moderate cases; Access First shifts sales calls toward affordability, BlinkRx prescribing, prior authorization support, and the exclusive $0 copay offer.

Pipeline and label expansion

• Phase 2 EoE trial tests acid suppression as first-line therapy; primary endpoint is eosinophil-count reduction, with symptom scores as secondary endpoints to inform Phase 3 design.

• EoE 12-week blinded data expected this quarter; the open-label portion is due to finish by Q1 next year, followed by FDA discussions on Phase 3 design.

• A successful FDA written request to include pediatric patients in Phase 3 could add six months of exclusivity; management hopes to know in 2027.

• As-needed Phase 3 data expected in H1 2028, with a supplemental filing likely in early 2029; management views PRN labeling as an expansion to patients seeking an alternative to daily PPI use.