INmune Bio Inc. has announced that its phase 1/2 CaRe PC trial evaluating INKmune therapy in patients with metastatic castration-resistant prostate cancer (mCRPC) has successfully met its primary and secondary endpoints. The trial is now closed to further enrollment, marking a significant milestone for the clinical-stage immunology company's NK cell-priming platform.
Trial Results and Safety Profile
The open-label study demonstrated that INKmune was well-tolerated across all three dose levels assessed, achieving the trial's primary endpoint of establishing safety. According to Mark Lowdell, PhD, Chief Scientific Officer and Chief Manufacturing Officer at INmune Bio, "INKmune was safe and effective at activating NK cells in a subset of more than half of these patients with advanced disease."
The therapy showed particular promise in patients with low baseline NK cell activation, who experienced the greatest improvement in biomarkers of NK cell activation. This finding helps define the target population for future clinical trials, providing crucial insights for patient selection strategies.
Evidence of Anti-Tumor Activity
Beyond safety endpoints, the trial revealed encouraging signs of clinical activity. "Excitingly we did see, in some patients, individual tumor lesions either reducing in size or completely disappearing during treatment, so we believe this could be evidence of a direct effect on tumor cell killing," Lowdell noted.
INKmune Mechanism and Administration
INKmune is described as a pharmaceutical-grade, replication-incompetent human tumor cell line that conjugates to resting NK cells. The therapy delivers multiple essential priming signals to convert cancer patients' resting NK cells into tumor-killing memory-like NK cells (mlNK cells). These primed NK cells have demonstrated persistence for more than 100 days in patients and function effectively in the hypoxic tumor microenvironment due to upregulated nutrient receptors and mitochondrial survival proteins.
The treatment offers practical advantages as a patient-friendly therapy that requires no pre-medication, conditioning, or additional cytokine therapy. INKmune can be easily transported, stored, and delivered through simple intravenous infusion on an outpatient basis.
Trial Design and Patient Population
The CaRe PC trial planned to enroll up to 30 patients with mCRPC across clinical sites in the United States. Eligible patients required a prostate-specific antigen level greater than 1.0 ng/mL at baseline, an ECOG performance score of 0 to 1, castrate levels of testosterone (less than 50 ng/dL), and adequate organ function.
Patients received up to three infusions of INKmune administered on days 1, 8, and 15, with dosing at three levels: low (1 x 10⁸ cells per infusion), medium (3 x 10⁸ cells per infusion), or high (5 x 10⁸ cells per infusion). Following treatment, patients were monitored for six months to assess immunologic and anti-cancer responses.
Future Development Plans
Based on the successful completion of this phase 1/2 trial in patients with advanced-stage disease, INmune Bio plans to design a randomized phase 2b trial targeting patients with less severe disease. This approach is intended to enable more robust measurement of the drug's effects and potential clinical benefits.
The final completion of the CaRe PC trial is expected in November 2025, with the company positioning INKmune as a tumor-agnostic therapy potentially applicable to various NK-resistant tumors including leukemia, lymphoma, myeloma, lung, ovarian, breast, renal, and nasopharyngeal cancers.
