A article has been published on the journal nature, that is reporting promising results from a Phase one human trial that is testing a new vaccine hopefully designed to help immune systems target brain tumours more efficiently. So far data is showing that the vaccine is safe and helps stimulate a significant response from the immune system that slows tumour progression. Phase 2 trials are already being planned.
Diffuse gliomas can spread across the brain. Making it much more difficult type of brain cancer to treat. However these tumours do often hold a common feature – around 70% of the lower grade gliomas actually share a single gene mutation affecting an enzyme called isocitrate dehydrogenase 1 (IDH1).
According to Michael Platte, from the German cancer research centre. The IDH1 mutation is unique to gliomas and leads to the creation of novel proteins called neo-epitopes. Michael has been working for years to create a vaccine that helps a patient’s immune system learn to target these IDH1 mutated cells.
Platten says: “Our idea was to support patients’ immune systems and to use a vaccine as a targeted way of alerting it to the tumour-specific neo-epitope,”
In 2015, after years of development and animal testing, the researchers finally began human trials for the novel IDH1 vaccine. The first step was to investigate how safe the vaccine was in human subjects and explore what kind of immune response it triggered.
No serious side effects were noted when around 33 patients with a newly diagnosed IDH1 glioma were recruited. Giving hope that the vaccine is safe.
93% of patients showed an effective response to the vaccine. Immune T cells specifically targeting the IDH1 mutation were detected in those responsive patients.
Patients with large numbers of circulating T cells in their bloodstream also showed tumour pseudo progression, a process where a tumour grows in size due to invading immune cells causing swelling. At the three-year follow-up point the cohort’s survival rate was 84 percent. No tumour growth was seen in 82 percent of patients displaying strong immunogenic responses to the vaccine after three years.
Platten is cautious about overstating the results from this phase 1 trial, saying no further efficacy conclusions can be made without larger trials and a control group. He does note a further phase 1 trial is already underway combining the experimental vaccine with checkpoint inhibitor immunotherapy, which is known to enhance immune system activity. The hope is the combination treatment will amplify immune responses.