Day One Biopharmaceuticals (DAWN) 44th Annual J.P. Morgan Healthcare Conference summary

Strategic and operational highlights

• Ended 2025 with over $440 million in cash and no debt, supporting continued investment in high-value programs.

• Completed the acquisition of Mersana, adding the Emmy Lee program to the pipeline alongside DAY301.

• OJEMDA established as the standard of care in relapsed/refractory pediatric low-grade glioma (pLGG), with plans to expand into frontline pLGG.

• Ipsen is driving OJEMDA's global expansion and registration outside the U.S.

• Projected path to over $1 billion in revenue, driven by OJEMDA and Emmy Lee.

Product performance and market development

• OJEMDA treated over 1,000 children to date and is the first approved product for this patient population.

• 2025 net product revenue reached $155.4 million, up 172% year-over-year, with Q4 revenue at $52.8 million (37% sequential growth).

• Full-year total prescriptions grew 181% versus 2024, with new patient starts in H2 outpacing H1 by 20%.

• Median duration of therapy for new patients is trending to 19 months, with persistency and extended treatment duration as key growth drivers.

• 2026 OJEMDA net product revenue guidance is $225–$250 million, driven by new patient starts, treatment persistence, and favorable payer dynamics.

Clinical data and future milestones

• Three-year data for OJEMDA showed 19.4 months' duration of response and 42.6 months' median time to next treatment.

• 75% of patients taking a drug holiday after 24 months remained treatment-free for 12 months, with successful retreatment outcomes.

• FIREFLY-2 frontline trial enrollment to complete in H1 2026, with data expected mid-2027 and potential approval in 2028.

• Emmy Lee phase I expanded data to be presented mid-2026, informing registration-enabling trial design.

• DAY301 phase I dose escalation data expected in the second half of 2026, with early evidence of antitumor activity.