AlloVir Inc. entered into a definitive merger agreement to combine with Kalaris Therapeutics in an all-stock transaction. Under the terms of the agreement, AlloVir will acquire 100% of the outstanding equity interest of Kalaris. After closing, the combined company is expected to operate under the name Kalaris Therapeutics and trade on Nasdaq under the ticker symbol “KLRS,” the companies said in a joint press release.

Kalaris is focused on the development of TH103, a novel, differentiated anti-VEGF investigational therapy. Developed by Napoleone Ferrara, MD, PhD, 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, the press releases stated. TH103 acts against VEGF as a decoy receptor and has been engineered for improved VEGF inhibition and longer retention in the retina.

“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,” said Dr. Ferrara. “This could potentially lead to enhanced durability with less frequent dosing in the clinical setting.”

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 who 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, the press release stated.