Advaxis Inc., a small US biotechnology company, has announced it will test its experimental immuno-oncology drug, ADXS-PSA, in combination with a high-profile immunotherapy from Merck & Co Inc., pembrolizumab, as a treatment for patients with advanced prostate cancer, the most common cancer among men other than skin cancer.
ADXS-PSA is a modified form of the Listeria bacterium fused to PSA, a protein shed by prostate tumors. This drug is specifically designed to boost lymphocytes into the tumor microenvironment, where they will recognize and eventually destroy cancer cells.
Pembrolizumab is a monoclonal antibody that inhibits the PD-1 protein expressed at the surface of tumor cells, a receptor responsible for the weakening of the anti-tumoral immune response.
ADXS-PSA will be tested both as a standalone treatment and in combination with pembrolizumab in a Phase I/Phase II clinical study. Using these different approaches and combining the two drugs will hopefully increase the chances of eliminating prostate cancer.
“If the combination of drugs shows an added effect, the companies would likely continue their collaboration,” Daniel O’Connor, chief executive officer of Advaxis said in a Reuters interview.
The study is expected to begin in early 2015, and while it will probably be conducted by a contract research organization, Merck will provide the pembrolizumab to be used in the trial.
PD-1 inhibitors have been the focus of intense research in the immune-oncology area, with trials revealing promising results in melanoma. However, this the first large study concerning anti-PD1 antibodies against prostate cancer.
“We think this combination gives us the opportunity to do early exploration in prostate cancer and bring immuno-oncology into this space,” David Mauro, executive director of oncology at Merck added in the same interview.
Merck’s pembrolizumab has already been tested in combination with other drugs from companies such as GlaxoSmithKline, Pfizer Inc., Amgen Inc., and Incyte Corp.
Furthermore, Advaxis had also recently announced a collaboration with AstraZeneca to test its MEDI4736 experimental therapy (anti-PD-L1 antibody) in a Phase I/II clinical study together with ADXS-HPV, an experimental immunotherapy targeting cells that have been transformed into dysplastic and malignant tissues by HPV, in patients with cervical cancer and head and neck cancer.
“We are excited to be working with Merck. Equally as exciting is the combination potential of our immunotherapy with Merck’s anti-PD-1 immune checkpoint inhibitor. We believe the combination of Advaxis Lm-LLO cancer immunotherapies and checkpoint inhibitors holds significant promise for the treatment of prostate and other cancers.” Daniel J. O’Connor stated in an Advaxis press release.