Day One Biopharmaceuticals

Today we've announced the completed enrollment in the FIREFLY-2 clinical trial, evaluating our medicine as a front-line treatment for pediatric low-grade glioma (pLGG). This is another step forward in our work to evolve the pLGG treatment paradigm and ultimately establish a new standard of care for patients newly diagnosed with pLGG. Read more: bit.ly/4uvVPgV

Today, @ServierPharma announced the successful completion of the acquisition of Day One. Learn more: servier.mediaroom.com/news-releases?…

Today we’ve announced a definitive agreement to be acquired by @Servier. Servier shares our deep commitment to advancing innovation in cancer along with our patient-focused methodology to address the most pressing areas of unmet need. Please refer to today’s press release for important information about this transaction. ir.dayonebio.com/news-releases/…

Day One reports fourth quarter and full year 2025 financial results. Read more: ir.dayonebio.com/news-releases/…

Day One announces preliminary 2025 OJEMDA Net Product Revenue and provides 2026 Revenue Guidance ahead of CEO Jeremy Bender's presentation at #JPM26 today at 5:15 pm PT. Read the press release here: bit.ly/45FFCvH

Today we've completed the acquisition of Mersana Therapeutics, expanding our pipeline with a clinical-stage antibody drug conjugate (ADC) emiltatug ledadotin (Emi-Le) targeting adenoid cystic carcinoma (ACC). This program is well aligned to our mission to develop innovative medicines for patients who urgently need them and broadens our opportunity for patient impact and continued growth. Read the press release here: bit.ly/4qAuPLf

Day One announces our three-year results from the Phase 2 FIREFLY-1 trial, presented in an oral presentation at the Society for Neuro-Oncology (SNO) Annual Meeting #SNO2025. Learn more here: bit.ly/47ZlMNJ

Join Dr. Cassie Kline on Sunday, November 23 at the Society of Neuro-Oncology (SNO) Annual Meeting to hear the three-year follow-up data from the Phase 2 FIREFLY-1 trial. #SNO2025

Day One to Acquire Mersana Therapeutics to Advance Mission to Bring New Medicines to People of All Ages with Life-Threatening Diseases. Read more: bit.ly/4qW6Qr5

Day One reports third quarter 2025 financial results. Read more: bit.ly/3WDNZmQ

Day One reports second quarter 2025 financial results. Read more: bit.ly/45BHRAC

We’re thrilled to announce that Michael Vasconcelles, M.D., has joined Day One as Head of Research & Development (R&D). Mike brings more than 25 years of experience in oncology research and development as an academic hematologist/oncologist and as an industry leader in large pharmaceutical, health technology, and emerging biotechnology companies. Mike will be instrumental in helping to drive innovative medical and scientific strategies to support OJEMDA’s growth while also continuing to build our pipeline of first- or best-in-class medicines for patients of all ages with life-threatening diseases. Read more: bit.ly/3Zq67Cj

Day One will be participating in a fireside chat at the 46th Annual Goldman Sachs Global Healthcare Conference in Miami on Tuesday, June 10th. Learn more about our pipeline and commitment to developing and commercializing targeted therapies for people of all ages living with life-threatening diseases. View the webcast here: bit.ly/43R1Fhv

We're gearing up for this year's @ASCO Annual Meeting and we're excited to see everyone in Chicago! #ASCO25 abstracts include data from the FIREFLY-1 study in pediatric low-grade glioma (pLGG): 📌Abstract 10029 on growth recovery in patients with BRAF-altered pLGG after discontinuing tovorafenib 📌Abstract 10037 on a post hoc analysis of rashes reported in  relapsed/refractory pLGG patients treated with tovorafenib If you're attending, stop by booth 34149 to meet the Day One team and learn more about how we're bringing novel targeted therapies to children and adults with cancer.

The Day One team is excited to be at the 2025 @ASPHO_hq Conference in Louisville this week! Stop by our booth 113 to hear how we're redefining what's possible for people of all ages living with cancer. #ASPHO2025 Learn more about our mission here: bit.ly/4gsrd8W

Day One reports first quarter 2025 financial results. Read more: bit.ly/3Smr6Sr

Every day, children and families face the life-changing reality of a brain tumor diagnosis, the most common solid tumor in pediatric patients and some of the hardest to treat. During #BrainTumorAwarenessMonth, we’re committed to shining a light on the profound impact brain tumors have on children and their families, and the crucial need for more research, treatment options, and support. Join us in raising awareness as we #GoGrayInMay.

Join us at the @AACR Annual Meeting 2025 in Chicago! #AACR25 abstracts include preclinical data on sequencing tovorafenib and MEK inhibitor therapy in BRAF fusion-driven tumor models and a Trial in Progress poster on the ongoing phase 1 trial of the PTK-7 targeted antibody drug conjugate, DAY301 . Learn more about the preclinical poster: bit.ly/4jalC8Q Learn more about the DAY301 TIP poster: bit.ly/4j4Sz6Q

We're honored to be named a finalist in the "Excellence in Rare Drug Development" at the 2025 @Citeline Awards! This recognition reflects our team's dedication and the urgency that drives us every day to get better, targeted medicines faster to patients of all ages who urgently need new options. We’re grateful for the patients and families who put their trust in us and inspire our work every day. Learn more: bit.ly/42hLslV

Christa Kerkorian, VP Patient Advocacy at Day One, will be speaking at the #PatientsAsPartners2025 conference on 3/17. She will discuss how Day One, patient advocates, and academia partnered to co-create a new framework for multistakeholder collaboration in pediatric cancer and drug development. You can download the framework here: bit.ly/4k9VufK Learn more about the conference here: bit.ly/3DyzrPg