Mice with ovarian tumors got four weekly doses of ERNA-101, at up to 10 million cells apiece, and the animals showed no treatment-related harm. That result, from a 50-day GLP toxicology study, is the first of three safety findings Ernexa Therapeutics reported on September 30.
The company, which trades on Nasdaq as ERNA, is developing ERNA-101 for advanced cancers. The therapy is an allogeneic induced mesenchymal stromal cell product engineered to express a fusion of IL-7 and IL-15, two cytokines that stimulate the immune system. Ernexa says the cells are meant to find a tumor, release those signals there and stay out of the rest of the body.
What the three studies found
In the toxicology study, immunocompetent C57BL/6 mice carrying established ID8 ovarian tumors received ERNA-101 into the abdomen once a week for four doses. The doses were 0.33 million, 1 million or 10 million cells per animal, compared against vehicle-treated controls. At every dose, clinical pathology was unchanged. An independent board-certified veterinary pathologist found no sign of treatment-related toxicity under the microscope. Some animals died before the study ended, but the company attributed every one of those deaths to tumor progression. A separate single-dose test turned up no evidence of acute cytokine release.
The second question concerned teratomas. Because ERNA-101 comes from induced pluripotent stem cells, the company tested whether the final cell product could form that kind of unwanted tumor. A three-month study in immunocompromised NSG mice was completed, and tissue analysis confirmed no tumors. In a six-month study, the live phase is finished and no gross evidence of teratoma formation appeared in treated groups. The tissue analysis for that longer study is still under way and is expected before the IND submission.
Third, a five-week biodistribution study used digital droplet PCR specific to ERNA-101 to track where the cells went. It found no significant signal in tumor-free animals or in tissue without tumor.
“Biodistribution goes directly to the heart of the ERNA-101 thesis,” said Robert H. Pierce, the company’s chief scientific officer. “We want the cells to go to the tumor, deliver their payload and not take up residence where they do not belong.”
From the lab to a first patient
The safety work follows earlier efficacy findings. In ovarian cancer models, ERNA-101 shifted the tumor environment from immunosuppressive to immune-activated and drew in more CD4+ and CD8+ T cells. Paired with PD-1 blockade, it produced a high rate of complete tumor clearance and durable survival, which the company says independent studies confirmed. These are all animal results.
Chief executive Sanjeev Luther said the core safety studies are done, GMP manufacturing has started and the FDA pre-IND meeting is behind the company. Ernexa plans to file its IND in the fourth quarter of 2026 for a first-in-human study in platinum-resistant ovarian cancer. If the FDA clears it, the company intends to dose its first patient, and it expects initial clinical data in the fourth quarter of 2027.
“Our focus now is execution and moving ERNA-101 toward the milestone that matters most: treating our first patient,” Luther said.
