DURHAM —  Istari Oncology has raised $43.4 million from 17 investors, according to an SEC filing.

Following the filing, the Durham-based clinical-stage biotechnology company received clearance from the U.S. Food and Drug Administration (FDA) for its investigational immunotherapy PVSRIPO, that now with approval, will be tested in a phase 1/2 open-label clinical trial.  The aim of the trial is to evaluate the application of PVSRIPO in activating a patient’s adaptive and innate immune system to bolster the body’s systemic anti-tumor response.

“For patients with most solid tumors, for example, those that express CD155, which is the vast majority of solid tumors, PVSRIPO delivered into the tumor may be able to stimulate the immune system to recognize and eliminate the tumor,” said W. Garrett Nichols, MD, MS, Chief Medical Officer at Istari Oncology in an interview with WRAL TechWire.

Immunotherapies could help long-term disease response, without side effects of high dosage chemotherapy, said Nichols. If a tumor can be biopsied, it can be injected, said Nichols, and if it can be injected, it can elicit an antitumor immune response that has the potential to control or eliminate the tumor.

That’s what the study will research, starting with two cohorts of adult patients who have bladder cancer.  The trial will evaluate the administration of PVSRIPO with or without PD-1/L1 inhibitors, and will begin enrolling patients later this year.

According to the company, the drug works by entering solid tumor cells and antigen presenting cells in the tumor microenvironment through the CD155 poliovirus receptor, which is expressed on most solid tumors.  This clinical trial, LUMINOS-103 (NCT04690699), newly cleared, will be an important test, said Nichols, as it will determine the versatility of the therapy to treat a wide range of tumors.

The clearance from the FDA is the third clearance this year, following other recent clinical trial progress, including a trial studying the application of the therapy in recurrent glioblastoma and in anti-PD-1/L1 refractory melanoma.

“Even with the approval of anti-PD-1/L1 therapies in certain solid tumor cancers, we believe there is still room for improvement,” said Matt Stober, CEO of Istari. “PVSRIPO’s mechanism is synergistic with these therapies and as an intratumorally administered agent, we expect little additive toxicity.”