Using the patient's immune system to attack cancer
RhoVac, a biotech company based at the Medicon Village, Sweden is focusing on the development of its therapeutic cancer vaccine, RV001, to prevent or limit cancer metastasis.
Despite the advances in cancer detection and therapy leading to better survival rates, cancer metastasis remains a major challenge, and accounts for around nine in ten cancer deaths. RhoVac's immunooncology approach to metastasis is to create a cancer vaccine that has potential to help the patient's own immune system to attack the cancer cells. This aims to limit the progression and spread of the cancer and therefore improve the patient's quality of life.
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 cancer cell," said Anders Ljungqvist, co-founder and CEO. "Many 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 a vaccine. Our approach is to target patients with metastases in an early stage," Ljungqvist added.
In the clinical pathway, treatment with RV001 vaccine comes after the removal of mother tumour with conventional cancer therapy, such as chemotherapy, radiation or surgery. The cancer vaccine controls the metastatic cells and limit the spread of the cancer.
Adjuvant therapies have shown efficacy in reducing metastasis, but many have a lot of side effects. The advantage of cancer vaccines is that they tend to have fewer side effects, and those that are seen are usually less severe.
RhoVac has made a decision to create an “off-the-shelf” vaccine targeting a known and prioritized cancer antigen, rather than creating one that is individualised to each patient, as Ljungqvist explained: "We believe that ours is a simpler economic model compared with the logistics required to produce a personalised vaccine."
Speeding into the clinic
RV001 is currently RhoVac's lead compound and single focus, and Ljungqvist wants to make sure that its development is as fast and efficient as possible. "We may take on additional projects if the opportunity is right; however, we are not a platform company, and currently we don't aim to create a pipeline. We only started development of RV001 in December 2015 and are already well into clinical phase, which shows the difference made by having a one hundred percent focus."
The current phase 1/2 trial, the first in human study, is conducted in post-prostatectomy prostate cancer patients who are being monitored, but not receiving further treatment. The study's primary focus is on safety and tolerability. The secondary objective is to evaluate the specific immune response against RhoC, and the exploratory endpoint will measure PSA values, to see if there is a link between PSA and immune response.
"The recruitment of patients to phase 1/2 is now closed and all patients are in treatment with the cancer vaccine," said Ljungqvist. "After treatment over approximately an eight-month period, we will continue monitoring the patients’ immune response against RhoC for one year, to get an idea of how often a booster injection would be needed."
Plans for the future
During 2017 and 2018, RhoVac plans to complete its ongoing phase I/II study, with results available mid-2018, and create a plan for the phase IIb study. The next step will then be to seek a licensee for the vaccine, or a trade sale for the company.