Avenzo Therapeutics, a clinical-stage biotechnology company developing next-generation oncology therapies, announced the closing of a $60 million Series B financing on September 22, 2025. The funding round was led by OrbiMed and SR One, with participation from new investor Longwood Fund and all existing investors, bringing the company's total capital raised to $446 million following its $386 million Series A/A-1 financing completed in November 2024.
The proceeds will support the advancement of Avenzo's expanding pipeline of potential best-in-class oncology drug candidates, which has grown from one to four clinical-stage assets during 2025. The company's portfolio includes both small molecule inhibitors and antibody-drug conjugates (ADCs) targeting cancers with high unmet medical needs.
Pipeline Expansion Drives Investment Interest
"Avenzo has made tremendous progress this year as we have advanced our pipeline from one to four clinical stage assets," said Athena Countouriotis, M.D., Co-founder, President and CEO of Avenzo. "This Series B financing enables us to build on this momentum as we continue the development of our potential best-in-class oncology programs."
The financing attracted participation from a broad syndicate of existing investors, including Foresite Capital, Lilly Asia Ventures, Surveyor Capital (a Citadel company), New Enterprise Associates (NEA), Deep Track Capital, Sofinnova Investments, Sands Capital, INCE Capital, TF Capital, Delos Capital, and Quan Capital.
Clinical-Stage Assets Target Key Cancer Pathways
Avenzo's pipeline centers on two primary therapeutic modalities: small molecule inhibitors targeting cell cycle regulation and bispecific ADCs. The company's small molecule program includes AVZO-021 and AVZO-023, which are novel, highly potent and selective inhibitors of CDK2 and CDK4, respectively—key enzymes involved in cell cycle regulation.
AVZO-021, the company's lead drug candidate, is currently being studied in a Phase 1 study for the treatment of advanced solid tumors and in combinations for HR+/HER2- metastatic breast cancer. AVZO-023 is being evaluated in a Phase 1/2 study for advanced solid tumors and in combinations for HR+/HER2- metastatic breast cancer.
Bispecific ADC Platform Advances
The company's ADC portfolio features AVZO-1418, a potential best-in-class EGFR/HER3 bispecific ADC currently in Phase 1/2 studies for advanced solid tumors. Avenzo's second ADC candidate, AVZO-103, represents a potential best-in-class Nectin4/TROP2 bispecific ADC, with the company planning to initiate a Phase 1/2 study in 2025 for patients with advanced solid tumors.
"We are excited to add Longwood to our syndicate and are grateful to all of our investors for their continued partnership as we strive to develop oncology therapies that help fight cancers with high unmet medical needs," Countouriotis stated.
The San Diego-based company's focus on developing next-generation oncology therapies positions it to address significant gaps in cancer treatment, particularly for patients with advanced solid tumors and specific breast cancer subtypes.
