BRISBANE, Calif., Dec. 16, 2025 (GLOBE NEWSWIRE) -- Day One Biopharmaceuticals, Inc. (Nasdaq: DAWN) (“Day One” or the “Company”), a biopharmaceutical company dedicated to developing and commercializing targeted therapies for people of all ages with life-threatening diseases, today announced that Dr. Jeremy Bender, chief executive officer, will present during the 44th Annual J.P. Morgan Healthcare Conference on Monday, January 12 at 5:15 p.m. Pacific Time / 8:15 p.m. Eastern Time. A live audio webcast of the ...

Core Insights - The updated three-year results from the FIREFLY-1 trial demonstrate that 77% of patients who entered a treatment-free observation period after OJEMDA treatment remained off therapy for at least 12 months [1][5] - The median time to next treatment (TTNT) following the initiation of OJEMDA exceeded 3.5 years [1][5] - Tovorafenib shows potential as a second-line standard of care for pediatric low-grade glioma (pLGG) [3][4] Trial Results - In the FIREFLY-1 trial, 76 evaluable patients showed an overall response rate of 53% (40/76), with a median duration of response of 19.4 months [3][14] - The median time to response was 5.4 months, and the median progression-free survival was 16.6 months [3][5] - Among 39 patients who entered a treatment-free observation period, the median treatment-free interval was not reached, with minimal tumor rebound observed [5] Safety Profile - No new safety signals were identified in the updated analysis, with common grade 3 or higher adverse events including decreased growth velocity and anemia [6][14] - The most frequently reported adverse reactions (≥30%) included rash, fatigue, and viral infections [14][15] Regulatory Status - Tovorafenib (OJEMDA) is approved by the FDA for pediatric patients aged 6 months and older with relapsed or refractory pLGG harboring a BRAF fusion or rearrangement [7][8] - The drug has received Breakthrough Therapy and Rare Pediatric Disease designations from the FDA [10] Industry Context - Pediatric low-grade glioma is the most common brain tumor in children, with significant unmet medical needs due to the lack of approved treatments targeting BRAF alterations [11][12] - The FIREFLY-1 trial is part of a broader effort to evaluate tovorafenib in pediatric patients with pLGG, highlighting the importance of targeted therapies in this demographic [13][18]

Company Overview - Day One Biopharmaceuticals, Inc. is focused on developing and commercializing targeted therapies for life-threatening diseases, particularly in pediatric cancer [3][4] - The company aims to address the critical unmet need in pediatric cancer therapeutic development, inspired by the initial conversations between physicians and families regarding cancer diagnosis and treatment [3] Upcoming Events - Management will participate in a fireside chat at the Piper Sandler 37th Annual Healthcare Conference on December 2, 2025, at 4:00 p.m. EST [1] - A live webcast of the discussion will be available on the company's Media & Investors page, with an archived replay accessible for 30 days post-event [2] Pipeline and Partnerships - Day One's pipeline includes targeted cancer treatments such as tovorafenib (OJEMDA™) and DAY301 [4] - The company collaborates with leading clinical oncologists, families, and scientists to identify and develop important cancer treatments [4] Communication Channels - Day One utilizes its Investor Relations website, X handle, and LinkedIn page to disseminate news, announcements, and financial performance updates [5]

Core Viewpoint - Mersana Therapeutics has entered into a definitive merger agreement with Day One Biopharmaceuticals, which includes an upfront cash consideration of $25.00 per share and potential contingent value rights cash payments of up to $30.25 per share, leading to a total deal value of approximately $285 million [2][4]. Company Overview - Mersana Therapeutics is a clinical-stage biopharmaceutical company focused on developing antibody-drug conjugates (ADCs) for cancer treatment, with a pipeline that includes Emi-Le, a Dolasynthen ADC targeting B7-H4 [6]. - Day One Biopharmaceuticals is a commercial-stage biopharmaceutical company dedicated to addressing unmet needs in pediatric cancer treatment [8]. Transaction Details - The merger will be executed through a tender offer followed by a second-step merger, with the tender offer required to commence within 10 business days of November 12, 2025 [3]. - The transaction has been unanimously approved by Mersana's board of directors, and closing is expected by the end of January 2026 [4]. - Mersana's executive officers and certain stockholders, holding approximately 8.5% of Mersana's outstanding shares, have signed agreements to support the tender offer [4]. Strategic Implications - The acquisition is expected to enhance the development of Emi-Le for treating patients with adenoid cystic carcinoma, a group with significant unmet medical needs [3]. - The combination of Mersana's assets and Day One's capabilities is anticipated to accelerate the delivery of new therapies to patients [3].

Company Overview - Day One Biopharmaceuticals is focused on developing and commercializing targeted therapies for life-threatening diseases, particularly in pediatric cancer [3][4] - The company aims to address the critical unmet need in pediatric cancer therapeutic development, inspired by the initial conversations between physicians and families regarding cancer diagnosis and treatment [3] Upcoming Events - Day One will host a live conference call and webcast on November 4, 2025, at 4:30 p.m. ET to report its financial results and discuss corporate progress for Q3 2025 [1] - The live audio of the webcast will be accessible on the company's Media & Investors page, with an archived version available for replay for 30 days post-event [2] Pipeline and Partnerships - Day One's pipeline includes targeted cancer treatments such as tovorafenib (OJEMDA™) and DAY301 [4] - The company collaborates with leading clinical oncologists, families, and scientists to identify, acquire, and develop important cancer treatments [4]

Company Overview - Day One Biopharmaceuticals is focused on developing and commercializing targeted therapies for life-threatening diseases, particularly in pediatric cancer [3][4] - The company aims to address the critical unmet need in pediatric cancer therapeutic development, inspired by the initial conversations between physicians and families regarding cancer diagnosis and treatment [3] Upcoming Events - Day One will host a live conference call and webcast on August 5, 2025, at 4:30 p.m. ET to report its financial results and discuss corporate progress for the second quarter of 2025 [1] - The live audio of the webcast will be accessible on the company's Media & Investors page, with an archived version available for replay for 30 days following the event [2] Pipeline and Partnerships - The company's pipeline includes targeted cancer treatments such as tovorafenib (OJEMDA™) and DAY301 [4] - Day One collaborates with leading clinical oncologists, families, and scientists to identify, acquire, and develop important cancer treatments [4] Communication Channels - Day One utilizes its Investor Relations website, social media platforms, and other channels to disseminate news, announcements, and financial performance updates [5]

Core Insights - Day One Biopharmaceuticals has appointed Dr. Michael Vasconcelles as Head of Research & Development, bringing over 25 years of oncology expertise to the company [2][3][4] - Dr. Vasconcelles will play a crucial role in advancing the company's pipeline and supporting the growth of its lead product, OJEMDA [3][5] Company Overview - Day One Biopharmaceuticals is focused on developing targeted therapies for life-threatening diseases, particularly in pediatric cancer, addressing a significant unmet need in therapeutic development [6][7] - The company aims to redefine cancer drug development and improve outcomes for patients of all ages from the moment of diagnosis [6] Leadership and Experience - Dr. Vasconcelles has a robust background in oncology research and development, having held leadership roles at ImmunoGen, Flatiron Health, Unum Therapeutics, and Takeda [4][5] - His previous experience includes transforming ImmunoGen into a global biotech enterprise and overseeing clinical development at Genzyme [4] Strategic Goals - The company is committed to expanding its pipeline of first- or best-in-class medicines, with a focus on delivering transformative therapies for children with cancer [3][5] - Dr. Vasconcelles' leadership is expected to enhance the company's medical and scientific strategies, driving growth and innovation [3][5]

Company Overview - Day One Biopharmaceuticals is focused on developing and commercializing targeted therapies for life-threatening diseases, particularly in pediatric cancer [3][4] - The company aims to address the critical unmet need in pediatric cancer therapeutic development, inspired by the initial conversations between physicians and families regarding cancer diagnosis and treatment [3] Upcoming Events - Day One will host a live conference call and webcast on May 6, 2025, at 4:30 p.m. ET to report financial results and discuss corporate progress for Q1 2025 [1] - The live audio of the webcast will be accessible on the Day One Investors & Media page, with an archived version available for replay for 30 days following the event [2] Pipeline and Collaborations - The company's pipeline includes tovorafenib (OJEMDA™), DAY301, and a VRK1 inhibitor program [4] - Day One collaborates with leading clinical oncologists, families, and scientists to identify, acquire, and develop important targeted cancer treatments [4] Communication Channels - Day One utilizes its Investor Relations website, X handle, and LinkedIn page to disseminate news, announcements, and financial performance updates [5]