#USA #Denver #ADC #Ovarian Cancer #Precision Biologics

Precision Biologics Unveils Groundbreaking ADC Research Against Ovarian Cancer

On September 20, 2025, during the AACR Special Conference held in Denver, Colorado, Precision Biologics, Inc. will shed light on its latest advancements in cancer therapy with the introduction of a new antibody-drug conjugate (ADC) designated PB-vcMMAE-5. This innovative treatment is specifically aimed at targeting human ovarian cancer that expresses truncated core 2 O-glycans, a glycosylation feature closely associated with cancer progression and metastasis.

Background on the ADC Development

Ovarian cancers have typically shown limited response rates to existing immune checkpoint inhibitors due to their capacity to suppress immune cell activity within the tumor microenvironment. This phenomenon primarily arises from the disrupted pathways of O-glycosylation found in these cancers, underlining the pressing need for alternative therapeutic measures. Precision Biologics has responded to this challenge by developing PB-vcMMAE-5, leveraging a monoclonal antibody (mAb) known as PB-223. This mAb has been optimized through affinity maturation from NEO-102, a chimeric human IgG1 mAb, ensuring that it exclusively binds to cancerous cells while leaving healthy tissues unaffected.

Furthermore, PB-223 was developed to possess a significantly enhanced binding affinity, evidenced by it being at least four times more effective than its predecessor. This translates into improved internalization capabilities into human cancer cell lines, particularly those expressing truncated core 2 O-glycans, marking significant strides in targeted therapy.

In Vitro and In Vivo Efficacy Studies

In Vitro Efficacy

The team at Precision Biologics conducted a robust series of in vitro tests across various human cancer cell lines, including those related to triple-negative breast cancer and ovarian cancer (OV-90). Findings demonstrated that PB-vcMMAE-5 was effective in inducing cell death, with the most significant results showing a cell kill rate of 92.51% in OV-90 cells at peak concentration. In stark contrast, the naked PB-223 did not exhibit any cytotoxic effects across all cell lines tested, emphasizing the robustness of the ADC.

In Vivo Safety and Efficacy Trials

Complementing the in vitro findings, in vivo studies were initiated in both rat and mouse models. Results indicated that PB-vcMMAE-5 exhibited a favorable safety profile, with no observed distress or weight loss in the subjects. In mouse models specifically designed for ovarian cancer, PB-vcMMAE-5 showcased a remarkable ability to significantly reduce tumor volume, particularly at doses of 6 and 9 mg/kg, while maintaining a benign safety profile.

The efficacy evaluation involved assessment of tumor growth through histological examinations using Ki-67 staining. Results indicated no viable tumor activity in mice treated with the highest dosage, revealing the ADC's potential for not only controlling tumor proliferation but potentially achieving a curative effect in cases of ovarian cancer expressing the targeted glycan.

Future Implications for Cancer Therapy

The findings presented by Precision Biologics underscore the promising role of PB-vcMMAE-5 as a viable therapeutic option for various forms of human malignancies that express core 2 O-glycans. Statistics indicate that this novel ADC has the potential to revolutionize treatment protocols for ovarian cancer and possibly other cancers exhibiting similar glycosylation patterns.

Details of these findings will be elaborated upon in a poster presentation at the AACR conference, and a PDF format of the poster will be accessible to the public starting September 19, 2025, via Precision Biologics' website. This groundbreaking development signifies hope for patients battling challenging cancer types and highlights the continual advancements in biopharmaceuticals aimed at tackling cancer more effectively and safely.