Struggling AlloVir finds new identity by merging into eye disease biotech

AlloVir has been reeling ever since a trio of phase 3 trial failures last year led the company to shed almost all of its staff. Now, the immunotherapy biotech has found a new path forward by merging into eye-disease-focused Kalaris Therapeutics.

The all-stock transaction will create a combined company operating under the Kalaris brand and focused on TH103, Kalaris’ anti-VEGF recombinant fusion protein that is undergoing a phase 1 trial for neovascular age-related macular degeneration. An initial readout is expected in the third quarter of 2025, and the companies alluded to plans to develop the candidate in other eye conditions like diabetic macular edema and retinal vein occlusion.

The merged company is expected to have $100 million in the bank, which is set to pave a cash runway into the final months of 2026. AlloVir’s stockholders will own 25.05% of the resulting entity, with Kalaris’ stockholders owning the other 74.95%.

The merger will mark a welcome final chapter for AlloVir, which began 2024 by laying off 95% of its workforce as it grappled with the consequences of three unsuccessful studies of posoleucel, an off-the-shelf multivirus-specific T-cell therapy, which was being developed to prevent infections or diseases caused by multiple viruses.

“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,” CEO Diana Brainard explained in a Nov. 8 release. “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.”

When it comes to anti-VEGF drugs, Regeneron and Bayer’s Eylea is top of the table, while Roche’s Vabysmo has also reached blockbuster status. Innovent, too, could have a contender in the form of IBI302, which held its own against Eylea in a phase 2 trial earlier this year.

TH103 was developed by Napoleone Ferrara, M.D., Ph.D.—whose team at Genentech in the 1980s was the first to isolate and clone vascular endothelial growth factor (VEGF). Ferrara is a member of Kalaris’ board, and the company said the drug has “demonstrated longer-acting and increased anti-VEGF activity” than Eylea in preclinical studies.

Kalaris was founded by investment firm Samsara BioCapital in order to take TH103 forward. The biotech’s CEO Andrew Oxtoby, who will also helm the merged company, said in Friday’s release that the biotech believes that TH103 “has the potential to be a meaningful advance for patients suffering from a number of neovascular and exudative retinal diseases.”