Antibody-drug conjugate plus docetaxel shows promise in metastatic prostate cancer

The novel antibody-drug conjugate PDS0301 (M9241) in combination with docetaxel demonstrated promising safety and immune response signals in patients with metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC), according to interim results from a phase 1/2 clinical trial (NCT04633252) announced by PDS Biotech, the developer of the therapy, in a news release.¹

The data are set to be presented at the upcoming International Cytokine & Interferon Society Annual Meeting in Athens, Greece.

According to PDS Biotech, PDS0301 is a “novel investigational tumor-targeting antibody-drug conjugate of Interleukin 12 (IL-12) that enhances the proliferation, potency, and longevity of T cells and natural killer (NK) cells in the tumor microenvironment.”¹

Overall, preliminary findings from the study showed a decrease in prostate specific antigen (PSA) levels across all doses of PDS0301 assessed (8.0 mcg/kg, 12.0 mcg/kg, and 16.8 mcg/kg), with decreases ranging from 4% to 100%. The investigators noted that the greatest immune responses and tolerability were observed with the 12.0 mcg/kg dose, though all doses of the tumor-targeting therapy were well-tolerated.

In total, 1 patient experienced grade 4 neutropenia. Changes in immune responses were found to be independent of the PDS0301 dose level.

“We are encouraged by the preliminary data from the Phase 1/2 clinical trial evaluating PDS0301 in combination with docetaxel for patients with metastatic prostate cancer, which has the potential to improve treatment outcomes for patients with advanced and refractory prostate cancers that have spread to other parts of the body,” PDS Biotech Chief Medical Officer Lauren V. Wood, MD, said in the news release.¹

In total, the trial enrolled 18 patients, of which 11 had mCSPC and 7 had mCRPC. The median patient age among all those included in the study was 69 years. Each patient received 3 dose levels of PDS0301 (8.0 mcg/kg, 12.0 mcg/kg, and 16.8 mcg/kg) via subcutaneous injection in combination with 75 mg/m2 docetaxel every 3 weeks.

PDS Biotech President and CEO Frank Bedu-Addo, PhD, added in the news release, “The interim data show that adding PDS0301 to docetaxel was associated with increases in peripheral activated natural killer cells, central memory CD8, proliferating CD4 and CD8 cells in addition to cytokines interferon-gamma and Interleukin 10 as well as decreases in T regulatory cells. As the first clinical study to evaluate docetaxel and an immunocytokine, we were pleased to see that the combination can be administered every 3 weeks and look forward to its continued evaluation and impact on clinical outcomes for the treatment of metastatic prostate cancer.”¹

The data on the therapy are set to be presented at the upcoming International Cytokine & Interferon Society Annual Meeting (Cytokines 2023) in Athens, Greece.²

References

1. PDS Biotech announces interim safety and immune response data from phase 1/2 clinical trial evaluating novel antibody drug conjugate PDS0301 combined with docetaxel to treat metastatic prostate cancer. News release. PDS Biotechnology. October 11, 2023. Accessed October 12, 2023. https://www.pdsbiotech.com/index.php/investors/news-center/press-releases/press-releases1/125-2023-news/879-iotechnnouncesnterimafetyandmmuneesponsea20231011

2. Combining an IL-12-based immunocytokine (PDS0301) with docetaxel in metastatic prostate cancer: preliminary safety and immune data. Presented at the International Cytokine & Interferon Society Annual Meeting. October 15-18. Athens, Greece. Abstract 249