Clinical trials successful with new cancer vaccine targeting metastases
The Swedish/Danish biotech company RhoVac is developing a therapeutic cancer vaccine, RV001, to prevent or limit cancer metastases. This may be a breakthrough in treating and even preventing cancer recurrence after primary tumour therapy.
Despite the advances in cancer detection and therapy leading to better survival rates, cancer metastases remain a major challenge, and account for around nine in ten cancer deaths.
“Our approach to limiting or even preventing metastases is to create a cancer vaccine that has the potential to help the patient’s own immune system in targeting and attacking metastatic cancer cells. This aims to limit or prevent the recurrence of cancer after primary tumour therapy keeping the patient cured after local therapy” says Anders Månsson, vice President at RhoVac.
Creating the cancer vaccine
RhoVac’s therapeutic cancer vaccine RV001 targets RhoC (Ras homolog family member C), a protein that is over-expressed in all cancer cells that have metastatic potential, across a wide range of cancer types. RV001 acts by triggering the production of RhoC-specific T cells.
“Our researchers were looking for a target that is widely and strongly expressed in cancer cells and an antigen that plays an important functional role for the metastatic cancer cell, and RhoC has been identified by the US National Cancer Institute as a priority target for cancer vaccination. Many other cancer vaccines have not performed as expected, because they have focused on treatment in patients with a heavy tumour burden, which may be too big a job for the immune system to take on singlehandedly. Our approach is instead to prevent recurrence of cancer from potentially remaining isolated metastatic cells or undetectable micro-metastases after primary tumour therapy”, Anders Månsson continues.
In the clinical pathway, treatment with the RV001 vaccine comes after the removal of the primary tumour with conventional cancer therapy, such as radiation or surgery. The aim is for the cancer vaccine to kill off the potentially remaining metastatic cells and as such prevent recurrence of the cancer.
“On top of being effective, it is also important that therapy that comes right after curative intent therapy is well tolerated, as patients are ideally cured at this stage and will not accept severe side effects. Judging by our data so far, RV001 has every chance of living up to these demands”, says Anders Månsson.
Next step will be a phase IIb and a licencing/acquisition deal
The phase I/II trial, the first in human RV001 study, was conducted in post-prostatectomy prostate cancer patients who would otherwise have been monitored, but who would not have been receiving further treatment”.
That study’s primary focus was on safety and tolerability. The secondary objective was to evaluate the specific immune response against RhoC. Results indicated excellent tolerability and a close to 90 per cent immune response rate that was stable over time. As such, RhoVac has now started on the last leg of its development journey, embarking on a >175 patient EU and US based phase IIb study in prostate cancer, aiming to show, with statistical significance, the efficacy of RV001 in preventing or postponing disease progression after curative intent therapy (prostatectomy or definitive radiation therapy). The study will conclude in 2021 and by that time RhoVac aims to secure a licensing or acquisition partner for phase III and a global launch of the compound.