AlloVir, Inc. and Kalaris Therapeutics announced a definitive merger agreement in which AlloVir will combine with Kalaris to form a company jointly focused on retinal disease.
First up: these companies.
We’ll start with AlloVir.
The clinical-stage cell therapy company is focused on the research and development of allogeneic, off-the-shelf multi-virus specific T cell (VST) therapies to prevent and stop life-threatening viral diseases.
Key to its science: the patented VST platform, designed to deliver these investigational VST therapies and restore viral immunity in immunocompromised patients.
- To note: These cells are “prospectively generated from healthy, eligible donors” that are then made immediately available to patients with T-cell deficiencies.
Now Kalaris.
Originally founded in 2019 by Samsara BioCapital, the clinical-stage ophthalmic biotechnology company is actively working toward developing and commercializing retinal (neovascular and exudative) disease therapies.
Its lead asset: TH103, a fully humanized, recombinant fusion protein intended for intravitreal delivery that acts against anti-vascular endothelial growth factor (VEGF) as a “decoy receptor.”
- Notably: The asset is also “engineered for longer-acting and increased anti-VEGF activity.”
Oh, do tell …
Well, TH103 features a design that uses “strong binding to heparan sulfate proteoglycans (HSPGs)”—which have been found to exist in all human retinal layers—resulting in a sequestering of TH103 within the eye, according to the company.
The potential of this: Enhanced durability plus less frequent dosing in a clinical setting.
And what is TH103 under clinical investigation for?
Neovascular age-related macular degeneration (nAMD).
As for clinical data thus far: Kalaris reported that the asset has already demonstrated “longer-acting and increased anti-VEGF activity” when evaluated in head-to-head preclinical research.
- Those details: Investigators hypothesized that binding to HSPG in the vitreous could promote intraocular retention and, as a result, lead to a reduced need for intravitreal injections.
And the findings from that research?
After designing a series of VEGF receptor 1 variants and identifying those with strong heparin-binding abilities (including binding to the vitreous matrix), researchers found the following:
- “Some of our variants have longer duration and greater efficacy in animal models of intraocular neovascularization than current standard of care,” they reported.
Let’s talk overall potential for the asset.
While we’re on the subject of longer duration, the companies noted that extending the interval between injections while maintaining visual acuity (VA) in a real-world setting has long been the goal for improving 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,” Kalaris stated.
Now to its clinical status.
TH103 is currently under clinical investigation in a phase 1 clinical trial (with enrollment ongoing) for treatment naïve nAMD patients.
- The goal: To evaluate:
- Safety
- PK/PD (check out this rundown)
- Maximum tolerated dose
- Preliminary data supporting the anti-VEGF effect of TH103 on fluid and visual acuity (VA)
- Initial data expected: Q3 2025
Future plans include developing the asset for other neovascular and exudative retinal diseases, the company reported.
Whew! That was … a lot. Now tell me about this merger.
Per the agreement, AlloVir will purchase 100% of Kalaris’s outstanding equity interest.
And once the merger is complete:
- Original AlloVir stockholders will own an estimated 25.05% of the combined company*
- Original Kalaris stockholders will own an estimated 74.95% of the combined company*
*Subject to certain adjustments noted in the agreement.
What will be the new company’s cash balance?
Approximately $100 million at close, with the transaction expected to provide a cash runway for operating expenses and capital expenditure requirements through Q4 2026.
And its new name?
The joint company will operate as Kalaris Therapeutics, Inc. (Nasdaq ticker symbol: KLRS).
Now its focus.
This involves accelerating the clinical development of TH103 for nAMD as well as potentially for two other retinal diseases:
- Diabetic macular edema (DME)
- Retinal vein occlusion (RVO)
And who will lead it?
Once the merger is complete, the following individuals will be at the helm:
- Andrew Oxtoby, current CEO of Kalaris
- Jeffrey Nau, PhD, MMS, current chief operating officer (COO) of Kalaris
- Matthew Feinsod, MD, medical lead for the new company
And for its Board of Directors:
- David Hallal (current AlloVir chairman) will remain chairman of the new company
See here for more board members of the newly-combined company—which includes four co-founders of Kalaris.
And lastly, when is this deal expected to close?
Reportedly: Q1 2025.