- Kalaris is a clinical-stage biopharmaceutical company founded by Samsara BioCapital and focused on development of TH103, a novel, differentiated and potentially transformative therapy for patients with neovascular and exudative retinal diseases
- Invented by VEGF pioneer Dr. Napoleone Ferrara, TH103 has demonstrated longer-acting and increased anti-VEGF activity in head-to-head preclinical studies against aflibercept, and could potentially provide a meaningful advance in treatment in the global $14 billion branded anti-VEGF retinal market
- TH103 is in a phase 1 clinical trial in patients with neovascular age-related macular degeneration with initial data expected in Q3 2025
- The combined company is expected to have a cash balance of approximately $100 million at close, which is anticipated in Q1 2025. Transaction expected to provide cash runway into Q4 2026
AlloVir, Inc. announced that it has entered into a definitive merger agreement to combine with Kalaris Therapeutics (“Kalaris”) in an all-stock transaction (the “Merger”).
Under the terms of the agreement, AlloVir will acquire 100% of the outstanding equity interest of Kalaris. Upon completion of the Merger, pre-Merger AlloVir stockholders are expected to own approximately 25.05% of the combined company and pre-Merger Kalaris stockholders are expected to own approximately 74.95% of the combined company, subject to certain adjustments described in the merger agreement.
Upon closing, the combined company is expected to have approximately $100 million in cash, which is expected to be sufficient to fund the combined company’s operating expenses and capital expenditure requirements into the fourth quarter of 2026. After closing, the combined company is expected to operate under the name Kalaris Therapeutics, Inc. and trade on Nasdaq under the ticker symbol “KLRS.”
"On behalf of the AlloVir board, I am thrilled that we have entered into this transformational merger agreement with Kalaris,” said David Hallal, chairman of the Board of AlloVir. “The combination of our financial resources, with Kalaris’ TH103 asset from the lab of the renowned Dr. Napoleone Ferrara, will help accelerate the clinical development of TH103 for neovascular age-related macular degeneration (“nAMD”) as well as other diseases such as diabetic macular edema (“DME”) and retinal vein occlusion (“RVO”). I am also looking forward to once again working with many members of the Kalaris board and management team with the goal of again ushering in a new era for the retina community by delivering an innovation for targeted VEGF inhibition.”
Kalaris is a clinical-stage biopharmaceutical company dedicated to the development and commercialization of treatments for prevalent retinal diseases, founded by Samsara BioCapital and focused on development of TH103, a novel, differentiated anti-VEGF investigational therapy.
Developed by Dr. Napoleone Ferrara, TH103 is a fully humanized, recombinant fusion protein currently being evaluated in an ongoing, Phase 1 clinical trial for the treatment of nAMD, with plans to develop TH103 for other neovascular and exudative diseases of the retina. TH103 acts against VEGF as a decoy receptor and has been engineered for improved VEGF inhibition and longer retention in the retina.
“AlloVir ran a thorough and strategic process, and we believe that this transaction represents the company’s commitment to delivering value to the AlloVir stockholders,” said Diana Brainard, CEO of AlloVir. “Kalaris is strongly positioned with an innovative clinical stage asset with the potential to disrupt the large anti-VEGF market, with near-term, value-inflecting milestones and a well-credentialed management team to lead the combined company.”
“We believe that TH103 has the potential to be a meaningful advance for patients suffering from a number of neovascular and exudative retinal diseases,” said Andrew Oxtoby, CEO of Kalaris Therapeutics. “Kalaris is currently enrolling a phase 1 clinical trial, and we look forward to reporting initial data in treatment naïve nAMD patients in the third quarter of 2025.”
Vascular endothelial growth factor A is the primary mediator and target of pathologic angiogenesis and exudation in retinal vascular diseases. Anti-VEGF agents have revolutionized treatment for these diseases, and the global market for branded anti-VEGF agents is approximately $14 billion.
Available data on real-world patient outcomes has consistently failed to replicate the results from registrational clinical trials, with most of this being attributed to suboptimal compliance.1,2,3,4,5
Extending the interval between injections while maintaining visual acuity in the real-world setting has been the goal to improve clinical outcomes. A novel therapeutic that could provide longer acting and increased VEGF inhibition may represent a clinically meaningful advance over the current standard-of-care.
“Napo Ferrara is a true pioneer in the anti-VEGF space, and I am grateful that he reached out to Samsara in 2019 to discuss the potentially market-changing therapy he was developing,” commented Srini Akkaraju, MD, PhD, managing partner of Samsara BioCapital, and Kalaris co-founder and board member. “TH103 may represent a significant advance in the treatment of multiple retinal diseases and builds on Dr. Ferrara’s legacy of developing anti-VEGF therapies over the past two decades. We are energized by the opportunity to enhance the standard-of-care and ease the treatment burden for patients.”
Building on Dr. Akkaraju’s comments, TH103 inventor and Kalaris board member Napoleone Ferrara, MD, PhD added, “This fusion protein was specifically engineered to utilize the natural configuration of important domains of VEGF Receptor 1 and has demonstrated both potent anti-VEGF activity and sustained ocular residence time in preclinical studies. This could potentially lead to enhanced durability with less frequent dosing in the clinical setting.”
Phase 1 Clinical Trial Details
Enrollment in Kalaris’ phase 1 clinical trial of TH103 has commenced, with initial data expected in the third quarter of 2025. The clinical trial is investigating TH103 in treatment-naïve patients that have been diagnosed with nAMD. The goals of the clinical trial are to evaluate safety, PK/PD, determine a maximum tolerated dose, and assess preliminary data supporting the anti-VEGF effect of TH103 on fluid and visual acuity.
About the Proposed Transaction: Management and Governance
Following the closing of the Merger, the combined company is expected to be led by current Kalaris CEO Andrew Oxtoby, current Kalaris Chief Operating Officer Jeffrey Nau, PhD, MMS, and Matthew Feinsod, MD as the combined company’s Medical Lead.
The combined company’s board of directors will be led by current AlloVir Chairman David Hallal, who will remain Chairman of the combined company’s board of directors.
Samir Patel, MD, one of the Kalaris co-founders and the current Executive Chairman of Kalaris, is expected to become a member of the combined company’s board of directors, which is also planned to include Mr. Oxtoby, current Kalaris board member Anthony Adamis, MD, PhD, and Kalaris co-founders and current board members Napoleone Ferrara, MD, PhD, Srini Akkaraju, MD, PhD, and Mike Dybbs, PhD. Two additional members are expected to be named to the combined company’s board of directors, one to be selected by AlloVir and the other to be mutually agreed upon by the two companies. In addition to Dr. Ferrara’s expertise as a pioneer in the discovery of VEGF and anti-VEGF drug development, several board members bring significant experience from the field of retinal disease, with Mr. Hallal, Dr. Patel, and Dr. Adamis all previously holding executive positions at a number of ophthalmology biotechnology companies over the past 20 years.
The transaction has been approved by the Boards of Directors of both companies and is expected to close in the first quarter of 2025, subject to approvals by the stockholders of each company, the expiration or termination of the waiting period under the U.S. Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, the effectiveness of a registration statement to be filed with the SEC to register the shares of AlloVir common stock to be issued in connection with the merger, AlloVir having a minimum of $95.0 million of net cash as of the closing, and other customary closing conditions. In connection with the Merger, directors, officers, and certain stockholders of AlloVir and Kalaris have executed support agreements, pursuant to which they have agreed to vote all of their shares of capital stock in favor of the Merger.
Leerink Partners is serving as exclusive financial advisor to AlloVir, and Goodwin Procter LLP is serving as legal counsel to AlloVir. Wilmer Cutler Pickering Hale and Dorr LLP is serving as legal counsel to Kalaris.