Day One Biopharmaceuticals (NASDAQ:DAWN) detailed accelerating commercial momentum for OJEMDA and outlined several upcoming clinical catalysts during its fourth-quarter and full-year 2025 earnings call. Management emphasized that 2025 marked the company’s first full year as a commercial-stage organization, with OJEMDA serving as the primary revenue driver and the pipeline expanding through internal development and the recently closed Mersana acquisition.
OJEMDA revenue growth and 2026 outlook
Day One reported full-year 2025 net product revenue of $155.4 million, up 172% year over year, driven by OJEMDA’s uptake in pediatric low-grade glioma (PLGG). The company also highlighted “double-digit sequential quarterly growth throughout 2025,” ending the year with fourth-quarter net product revenue of $52.8 million, a 37% sequential increase over Q3.
Based on the performance and early-year demand trends, Day One reiterated its 2026 OJEMDA net product revenue guidance of $225 million to $250 million. Management said results within the range will depend primarily on persistence on therapy and the pace of new patient starts.
Three-year FIREFLY-1 update: durability and “time to next treatment”
Day One’s R&D leadership reviewed three-year follow-up data from FIREFLY-1, the registration trial supporting OJEMDA in relapsed or refractory, BRAF-altered PLGG. The company said the data were presented at the Society for Neuro-Oncology meeting in November 2025 and had a median on-study duration of 40.6 months.
On safety, management said the three-year dataset showed no new safety signals compared with data at initial approval. The call highlighted low discontinuation due to adverse events and described low-grade adverse events including rash, fatigue, and gastrointestinal events such as nausea or vomiting. Higher-grade or more frequent events cited included decreased growth velocity, anemia, occasional more severe rash, and certain asymptomatic laboratory abnormalities (including elevated CPK or ALT), which management said remained consistent with the product label.
On efficacy, management reported a 53% objective response rate, compared with 51% at the time of approval, along with a median duration of response of 19.4 months and a median time to response of 5.4 months.
A key theme of the update was how radiographic progression may not reflect real-world clinical decision-making in PLGG, where physicians may continue treatment despite imaging changes. Day One said all 38 patients who experienced progression while on OJEMDA continued treatment for a median of 9.3 months, and 45% of those patients demonstrated further tumor reduction after initial documented progression.
The company contrasted traditional progression-free survival (PFS) with alternative endpoints meant to capture real-world practice:
- Median PFS: 16.6 months
- Median TTNT (time to next treatment): 42.6 months
Management said these analyses are being incorporated into the ongoing randomized Phase III FIREFLY-2 trial evaluating OJEMDA in the frontline PLGG setting versus standard chemotherapy regimens.
Commercial execution: new patient starts, persistence, and payer coverage
Commercial leadership said OJEMDA’s growth in 2025 reflected increasing physician confidence, broader adoption, and an expanding base of patients persisting on therapy. The company’s 2026 execution priorities were described as (1) driving new patient starts and (2) optimizing persistence.
Day One reported that in the second half of 2025, new patient starts increased 25% versus the first half, attributing the acceleration to growing clinical experience and “growth velocity” data presented at ASCO that showed catch-up growth after completing treatment.
On persistence, management said median duration of therapy for commercial PLGG patients is “trending to 19 months,” and noted that longer treatment durations contributed to second-half performance. In the Q&A, the company described internal analyses suggesting persistence may be stronger in certain groups, including earlier-line relapsed/refractory patients, physicians with more OJEMDA experience, dose-adjusted patients (with all doses priced the same), and patients enrolled in the company’s patient support program.
Day One also cited favorable payer dynamics, stating coverage rates for PLGG remain above 95%, with more than 90% of patients approved on the first request. The company said over 95% of PLGG patients receive paid drug, resulting in minimal reliance on free drug programs.
Pipeline expansion: Emi-Le acquisition and DAY301 progress
Beyond OJEMDA, management highlighted pipeline expansion through the acquisition of Mersana, which closed in January 2026. Day One is integrating emiltatug ledadotin (Emi-Le), an antibody-drug conjugate (ADC) targeting B7-H4 with an auristatin payload (FHPA). The company said Phase I data presented at ASCO 2025 showed antitumor activity in adenoid cystic carcinoma (ACC), a rare cancer with no current approved treatments for aggressive disease.
Day One said it plans to share additional clinical data for Emi-Le in mid-2026, including an updated ACC cohort and expanded safety dataset, and intends to initiate discussions with the FDA regarding an accelerated clinical development approach. Management characterized ACC as an area of high unmet need, citing an estimated median survival of 2 to 3 years for the expected registration population.
When asked about other potential indications such as triple-negative breast cancer, management said its primary focus is ACC while it continues to evaluate other opportunities, and noted that future disclosures would include a comprehensive safety dataset.
The company also discussed DAY301, a PTK7-targeted ADC using a topoisomerase I inhibitor payload and a hydrophilic, stable linker with a drug-antibody ratio of 8. The Phase I program is in dose escalation and schedule optimization, and management anticipates sharing data and a program update in the second half of 2026. In the Q&A, the company declined to specify dose cohorts or DLT/MTD details ahead of the planned update, but said it is encouraged by early signs of anti-tumor activity.
Expenses, cash position, and gross-to-net expectations
Day One reported total costs and operating expenses of $81 million in Q4 2025 and $286 million for the full year, compared with $95 million in Q4 2024 and $348 million for full-year 2024. Management attributed the year-over-year decline primarily to the absence of one-time expenses related to the in-licensing of DAY301 in 2024.
Gross-to-net for OJEMDA remained within the company’s previously communicated 12% to 15% range in 2025. Looking ahead, Day One guided to a 16% to 19% gross-to-net range in 2026.
Day One ended 2025 with approximately $441 million in net cash and no debt. Management said the balance did not include the impact of the Mersana acquisition (which closed in early January 2026) and added that it believes it has ample capital to fund current plans without additional financing.
About Day One Biopharmaceuticals (NASDAQ:DAWN)
Day One Biopharmaceuticals, Inc (NASDAQ: DAWN) is a clinical-stage biopharmaceutical company focused on the discovery and development of targeted therapies for oncology. The company employs a precision medicine approach, leveraging biomarker-driven strategies to identify patient populations most likely to respond to its investigational compounds. By concentrating on well-validated molecular drivers of cancer, Day One seeks to deliver first-in-class or best-in-class therapies with the potential for meaningful clinical benefit.
The company’s pipeline includes several small-molecule candidates in various stages of development.
