Prostate cancer immunotherapy candidate

PROSTVAC (rilimogene galvacirepvec/rilimogene glafolivec, or “rilimogene”) is a prostate specific antigen (PSA)-targeted immunotherapy candidate designed to enhance or stimulate the body’s immune response, specifically T cells that will home to and kill prostate cancer cells, altering the course of the disease and improving overall survival of patients with prostate cancer. PROSTVAC employs two poxviruses (vaccinia and fowlpox) in a prime-boost vaccine regimen.

A robust data package has been established that includes 19 ongoing or completed clinical studies, comprising more than 2,000 patients, the majority of which have been actively treated with PROSTVAC, which has been generally well-tolerated.

Data to date suggest that PROSTVAC has potential in combination with other therapies and/or in earlier stages of the disease.

  • Prostate cancer is the second most common cancer in men
  • Approximately 1 in 6 men will be diagnosed with prostate cancer during his lifetime
  • An estimated 904,000 new cases of prostate cancer were diagnosed. Nearly two thirds of those diagnosed were men aged 65 or older
  • An estimated 258,000 men died of prostate cancer

Source: American Cancer Society, Global Cancer Facts & Figures 2nd Edition, 2008

  • When PSA-TRICOM is presented to the immune system in the PROSTVAC regimen, cytotoxic T lymphocytes (CTLs) are generated that may recognize and kill PSA-expressing cancer cells
  • A cascade effect may also occur, which may overcome the immunosuppressive cancer microenvironment and lead to immune recognition of other tumor-associated antigens

PROSTVAC is being developed in partnership with the National Cancer Institute under a formal Collaborative Research and Development Agreement and has been the subject of 9 completed and 10 ongoing clinical studies.

19 ongoing or completed PROSTVAC clinical studies

  Completed Ongoing
Phase 1 4 -
Phase 2 4 10
Phase 3 1* -
Total 9 10
Total patients 1,600+ 500+

* discontinued

The postulated mechanisms of action of Bavarian Nordic’s active immunotherapies and checkpoint inhibitors suggest that they may be well suited for combined use.

Checkpoint inhibitors are postulated to amplify the anticancer activities of PROSTVAC

Checkpoint Inhibitors

Immune checkpoint inhibitors have robust clinical activity, but in only a fraction of patients treated. Their unfocused immune activation leads to toxicity concerns. By contrast, active immunotherapies may provide improvements in long-term outcome, but less significant short-term response. Their activity may be modulated by checkpoint inhibition.

Preliminary evidence from early clinical studies suggests potential benefit from the combination of PROSTVAC and checkpoint inhibition.

PROSPECT was a global, randomized, double-blind, placebo-controlled phase 3 study conducted under a Special Protocol Assessment (SPA) from the FDA. The objective of the study was to determine whether PROSTVAC® alone or in combination with GM-CSF is effective in prolonging overall survival in men with few or no symptoms from metastatic, castration-resistant prostate cancer (mCRPC).

By January 2015, the study had been fully enrolled with 1,297 asymptomatic or minimally symptomatic mCRPC patients. Patients were enrolled at more than 200 sites in 15 countries, including Australia, Belgium, Canada, Denmark, Estonia, France, Germany, Iceland, Israel, Netherlands, Poland, Russia, Spain, United Kingdom and the United States.

In September 2017, an independent Data Monitoring Committee (DMC) determined, based on a preplanned interim analysis, that continuation of the Phase 3 PROSPECT study of PROSTVAC® in patients with metastatic castration-resistant prostate cancer (mCRPC) was futile.