Phase 1 Trial for KMV002, a New Prostate Cancer Vaccine for mCRPC

A new phase 1  clinical trial will investigate KMV002, an experimental therapeutic cancer vaccine for patients with metastatic prostate cancer that has become resistant to androgen-targeting treatments (mAPMR, previously mCRPC). Patients will receive either five or six doses of KMV002, a combination of SN3001C and an immune-stimulating substance known as a CpG ODN adjuvant.

KMV002, also known as IPT-PAP, is designed to help the immune system recognise and attack prostate cancer cells. It targets prostatic acid phosphatase (PAP), a protein associated with prostate cells that has already been used as a target in cancer vaccines. The treatment uses an engineered protein to deliver this target to dendritic cells, which are responsible for activating the immune system. The CpG adjuvant is added to strengthen this response, with the aim of stimulating T cells capable of recognising and destroying cancer cells.

The trial will mainly assess the vaccine’s safety, tolerability and the most suitable dose for future studies. An earlier Chinese study also investigating KMV002 and includes several measures of immune activity. Researchers will look for PAP-specific T-cell responses, changes in immune activity and early signs of effectiveness, including tumor shrinkage, radiographic progression-free survival and PSA reductions of at least 50%.

The approach is interesting because prostate cancer has generally been difficult to treat with immunotherapy. One reason is that prostate tumours often contain relatively few active immune cells and can suppress immune responses. KMV002 aims to improve the immune system’s ability to identify prostate cancer, but whether this will lead to better tumour control remains unknown. In particular, it is unclear whether the activated T cells will be able to reach and attack metastases, especially those in the bones.

Targeting PAP is not entirely new. Sipuleucel-T, an approved prostate cancer immunotherapy, also targets this protein, although it works differently from KMV002. This provides some support for PAP as a vaccine target, but does not establish that KMV002 will be effective. Combining the new vaccine with other cancer treatments could also be explored in the future.

Clinical trial.