Rallybio Corporation and Avenzo Therapeutics Announce Merger Agreement to Advance Next-Generation Oncology Therapies and $215 Million Concurrent Private Placement

On June 1, 2026 Rallybio Corporation (Nasdaq: RLYB) ("Rallybio") and Avenzo Therapeutics, Inc. ("Avenzo"), a clinical-stage biotechnology company developing next-generation oncology therapies, reported that they have entered into a definitive agreement pursuant to which Rallybio will acquire Avenzo through a merger transaction (the "Merger"). Upon completion of the Merger, the combined company is expected to operate under the name Avenzo Therapeutics, Inc. and is expected to trade on Nasdaq under the ticker symbol "AVZO".

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In connection with the Merger, Avenzo entered into subscription agreements for a concurrent oversubscribed private placement financing of $215 million in gross proceeds (the "Financing" and, together with the Merger, the "Transaction"). The Financing included participation from new investors including a leading mutual fund, Blackstone Multi-Asset Investing, accounts advised by T. Rowe Price Investment Management, Inc., a leading life sciences fund, Vivo Capital, Affinity Asset Advisors, ADAR1 Capital Management, and existing investors including OrbiMed, SR One, Foresite Capital, Surveyor Capital (a Citadel company), Longwood Fund, New Enterprise Associates, Deep Track Capital, Sands Capital, Lilly Asia Ventures, Sofinnova Investments, and other institutional investors. The combined company expects its cash balance at closing to fund operations into late 2028 and support advancement of its four clinical-stage programs through multiple clinical milestones, including updated Phase 1 data across the pipeline, initial clinical data for the combination of AVZO-023 and AVZO-021 with fulvestrant, and the initiation of multiple Phase 2 studies across the pipeline.

The Transaction has been unanimously approved by the boards of directors of both companies and is expected to close in Q4 2026, subject to certain closing conditions, including the approval by the stockholders of each company, the effectiveness of a registration statement to be filed with the Securities and Exchange Commission (the "SEC") to register the shares of Rallybio common stock to be issued in connection with the Transaction, and the satisfaction of other customary closing conditions. Rallybio intends to distribute substantially all of its pre-closing net cash to its pre-closing stockholders in connection with the Transaction. Accordingly, following closing, pre-Transaction Rallybio equityholders are expected to own approximately 2.8% of the combined company, and pre-Transaction Avenzo equityholders (inclusive of investors participating in the Financing) are expected to own approximately 97.2% of the combined company, calculated on a treasury stock method basis and assuming Rallybio has no net cash at closing (as a result of the distribution of its pre-closing net cash). In addition, pre-closing Rallybio stockholders will receive contingent value rights ("CVRs") entitling them to the net cash proceeds received by the combined company from the previously announced sale of interests in Rallybio’s former REV102 program and potential disposition of Rallybio’s other legacy assets.

Transaction Highlights

Pipeline of Four Next-Generation Clinical Stage Oncology Programs: Avenzo has built a portfolio of potentially differentiated targeted small molecules and antibody-drug conjugates ("ADCs") for various solid tumor indications with significant commercial potential. Avenzo is currently conducting four ongoing U.S.-based studies evaluating its four clinical stage drug candidates:
Selective CDK portfolio: AVZO-021 and AVZO-023 are selective inhibitors of CDK2 and CDK4, respectively, designed to address the key limitations of approved CDK4/6 inhibitors in hormone receptor-positive ("HR+")/human epidermal growth factor receptor 2-negative ("HER2-") breast cancer. AVZO-021 has been studied in 64 total patients as monotherapy and in combination with fulvestrant in a Phase 1 study, demonstrating clinical activity in heavily pretreated patients with HR+/HER2- breast cancer and a generally well tolerated safety profile. Avenzo plans to present updated safety and efficacy results from the Phase 1 portion of the Phase 1/2 study later today at the 2026 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting. AVZO-021 and AVZO-023 are being studied in the Phase 1 portion of the ongoing ORION-1 Phase 1/2 study in HR+/HER2- breast cancer, where AVZO-023 is administered in combination with endocrine therapy, with or without AVZO-021. Avenzo plans to present preliminary, updated data of AVZO-023 in combination with fulvestrant from the Phase 1 portion of the ORION-1 study in late 2026.
Bispecific ADC portfolio: AVZO-1418, a bispecific ADC targeting EGFR and HER3, has been studied in over 30 patients across multiple solid tumors in the Phase 1 portion of the ongoing AVENTINE-1 Phase 1/2 study, with clinical activity observed across multiple dose levels and solid tumor indications. AVZO-103, a bispecific ADC targeting Nectin4 and TROP2, is currently being evaluated as monotherapy in multiple tumor types, including urothelial cancer, in the Phase 1 portion of the ongoing BEACON-1 Phase 1/2 study. Avenzo plans to present preliminary, updated data from the Phase 1 portion of the AVENTINE-1 study and initial data from the Phase 1 portion of the BEACON-1 study in late 2026.
Experienced leadership team: The combined company will be led by Dr. Athena Countouriotis, Chair, President and Chief Executive Officer ("CEO") of Avenzo, with Dr. Mohammad Hirmand, Co-founder and Chief Medical Officer of Avenzo, and an experienced management team that brings deep expertise in oncology drug development.
Strong capital foundation: Pro-forma cash at closing is expected to fund the combined company through multiple anticipated clinical milestones in 2027 and 2028.
"This transaction represents a turning point for Avenzo as we transition to a public company and advance our four potentially differentiated, clinical stage programs for patients with cancer," said Athena Countouriotis, M.D., Chair, President, and CEO of Avenzo. "By combining with Rallybio and securing $215 million in additional capital from a distinguished group of healthcare investors, we believe that we have the resources to advance our pipeline beyond multiple potential data read outs."

"We are pleased to announce this transaction with Avenzo, which represents a compelling opportunity for Rallybio stockholders to participate in the development of a portfolio of potentially differentiated oncology therapies," said Stephen Uden, M.D., Co-Founder and CEO of Rallybio. "Rallybio’s Board of Directors and management team are supportive of this transaction and believe the combined company is well positioned to execute on the development of its pipeline under Avenzo’s leadership."

About the Proposed Transaction
Under the terms of the merger agreement, Rallybio will acquire Avenzo pursuant to the Merger. At the closing of the Merger, Avenzo stockholders will receive newly issued shares of Rallybio common stock, with the exchange ratio to be determined based on the relative valuations of the two companies at closing. Immediately following the closing of the Merger, the combined company will change its name to Avenzo Therapeutics, Inc. and trade on Nasdaq under the ticker symbol "AVZO".

In connection with the Transaction, a syndicate of leading healthcare institutional investors and mutual funds has committed to invest $215 million in the Financing. The Financing is expected to close immediately prior to the Merger. In connection with the Transaction, certain stockholders of Avenzo and Rallybio have executed support agreements, pursuant to which they have agreed to vote all their shares of capital stock in favor of the Transaction.

Leerink Partners is serving as exclusive financial advisor, and Cooley LLP is serving as legal counsel to Avenzo. Evercore is serving as lead financial advisor, Citizens Capital Markets & Advisory is serving as co-financial advisor, and Ropes & Gray LLP is serving as legal counsel to Rallybio. Leerink Partners, Goldman Sachs & Co. LLC, Piper Sandler, and Guggenheim Securities are serving as placement agents for the Financing. Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. is serving as legal counsel to the placement agents.

Conference Call Information
Rallybio and Avenzo will host a joint conference call and webcast on June 1, 2026 at 8:30 a.m. ET. Please access the presentation by clicking on the following link: View Source

(Press release, Avenzo Therapeutics, JUN 1, 2026, View Source [SID1234666298])