Aura Biosciences said eight of 10 patients with a rare eye cancer who received a therapeutic dose of its experimental virus-like drug conjugate saw their tumors stop growing at one year.
Of the 10 patients with small choroidal melanoma, nine saw their vision preserved — an important metric for these patients since treatment alternatives like surgery and radiation can leave them blind or with some vision loss. Most of the patients in the cohort were at high risk for vision loss due to the position of their tumors. The results were presented Thursday at the Retina Society’s annual meeting in Lisbon.
“The visual acuity preservation is not just for safety,” Aura CEO Elisabet de los Pinos told Endpoints News. “It’s part of the efficacy of the drug because, otherwise, if you’re going to be blinded anyways, you can just treat with radiotherapy. We already have that.”
With this type of cancer, which is often diagnosed early, the goal is to stop the tumors from growing, according to de los Pinos.
The Phase 2 study enrolled 22 total patients across a series of doses. Adverse events were generally mild, and included four cases of grade 1 inflammation in the eye.
The company started a Phase 3 study called CoMpass in December. It plans to enroll around 100 patients.
Aura reported that the average post-treatment tumor growth rate was 0.011 mm/year for responders compared to 0.351 mm/year before they entered the study — good for a p-value of less than 0.0001.
Aura’s experimental virus-like drug conjugate for eye cancer is known as belzupacap sarotalocan, or bel-sar for short. In choroidal melanoma, there are currently no approved drugs, and patients are treated typically with either radiation or surgery if their cancer starts growing faster.
Bel-sar is delivered to a region in the eye called the suprachoroidal space, and it’s designed to bind selectively to tumor cells via specific sugar branches that are seen across solid tumor types but not on normal cells. Once it’s there, infrared light is used to activate a photosensitizing drug, which bursts the cells and kills them. That cell rupturing induces an immune response that is meant to further spur tumor cell killing.
The Boston-based biotech was spun out of work conducted at the NIH, which Aura still works closely with for research and animal studies. De los Pinos said the company is funded to the second half of 2026.
Aura plans to report data on a bladder cancer drug in October.