Option exercise triggers $25M payment to Pinetree.

CAMBRIDGE, Mass. , April 29, 2026 /PRNewswire/ -- Pinetree Therapeutics, Inc. ("Pinetree"), a biotechnology company pioneering next-generation targeted protein degradation approaches for cancer and other serious diseases, today announced that AstraZeneca (LSE/STO/NYSE: AZN) has exercised its option under the companies' previously announced agreement to obtain an exclusive global license to develop and commercialize PTX-299, a first-in-class bispecific antibody degrader targeting EGFR.

The option exercise follows encouraging preclinical progress and represents an important milestone in the collaboration between the two companies. Under the terms of the agreement, AstraZeneca will assume responsibility for global development and commercialization of the therapeutic candidate.

"This milestone marks an important validation of our AbReptor™ platform," said Hojuhn Song, Ph.D., Founder and CEO of Pinetree Therapeutics. "We are pleased that AstraZeneca has exercised its option to advance PTX-299, and we look forward to seeing them continue the development of this promising therapeutic candidate. By combining Pinetree's breakthrough protein degradation platform with AstraZeneca's global expertise in cancer drug development, we believe that PTX-299 has the potential to bring a meaningful new treatment option to patients with EGFR-driven cancers."

EGFR plays a critical role in the growth and survival of cells in multiple tumor types. While EGFR-targeted therapies have transformed patient outcomes, resistance can develop, highlighting the need for new therapeutic strategies. By leveraging Pinetree's antibody-based protein degradation technology, PTX-299 is designed to selectively eliminate disease-driving EGFR proteins rather than simply inhibiting their activity, potentially overcoming key resistance mechanisms.

The therapeutic candidate was developed using AbReptor™, Pinetree's proprietary multispecific antibody-based targeted protein degradation platform. In contrast to conventional monoclonal antibodies that rely on functional inhibition, AbReptor™ drives the active removal of disease-associated proteins through targeted degradation. By enabling the elimination of membrane-bound and extracellular targets, this platform extends beyond the limitations of traditional inhibition-based antibody therapies.

Under the terms of the agreement, AstraZeneca's exercise of the option triggers a $25 million option closing payment to Pinetree. Pinetree is also eligible to receive potential future development, regulatory, and commercial milestone payments and tiered royalties on global net sales if the product is successfully developed and commercialized. The total potential value of the agreement exceeds $500 million.

About Pinetree Therapeutics
Pinetree Therapeutics, based in Cambridge, MA, is a preclinical-stage biotech company developing next-generation targeted protein degraders (TPDs) to overcome drug resistance and tumor recurrence in oncology, with applications in inflammation and immunology. Its proprietary AbReptor™ platform enables selective degradation of membrane-bound and extracellular proteins, offering a differentiated mechanism of action and durable therapeutic benefit. Pinetree is also advancing trispecific degraders and ADC-integrated platforms.

For more information, visit https://www.pinetreetx.com/.

Contact:
Zachary Park
pr@pinetreetx.com

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SOURCE PineTree Therapeutics