ProscaVax consists of a combination of the PSA protein (a hallmark of prostate cancer) with the cytokines interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF). [Cytokines are molecules that participate in immune responses.]
The study (NCT03579654) intends to assess the safety and efficacy of ProscaVax in about 120 patients with low-risk, localized and untreated prostate cancer. The scientists will evaluate whether the vaccine leads to a change in prostate cancer progression compared to patients on active surveillance, in which disease progression is monitored before other strategies, such as surgery or radiotherapy, are considered.
PSA doubling time – the time needed for blood levels of PSA to double, considered a predictor of cancer progression and survival – and adverse events will also be assessed.
Treatment-arm patients will be start with a four-month induction period, being given six doses of ProscaVax at weeks 1, 2, 3, 7, 11 and 15. This period will be followed by maintenance injections once every month, and alternating between low-dose IL-2 alone and the ProscaVax vaccine for six months.
The single-site trial, which is expected to finish in August 2022, will be conducted at Beth Israel Deaconess Medical Center in Boston, and includes the Dana-Farber Cancer Institute. Patient enrollment has not yet started.
“The initiation of this study represents a milestone moment for our company, shareholders and the more than 160,000 men that will learn they have prostate cancer this year,” Jonathan Head, OncBioMune’s CEO, said in a press release.
Head added that this will be the first time that prostate cancer patients will be treated with a vaccine “rather than waiting for disease progression or jumping into more invasive treatments options that frequently are accompanied by very unpleasant side effects, such as urinary incontinence and impotence.”
OncBioMune reported results of a Phase 1a/1b study (NCT02058680) in January, showing that ProscaVax reduced tumor growth in 70% of recurrent prostate cancer patients after a minimum of 31 weeks of treatment.
Based on this successful safety and efficacy data, OncBioMune, based in Louisiana, decided to skip the 1b portion of that trial and advance to Phase 2.