We want to keep you updated and informed on the exciting developments happening with diagnosis and treatment of brain tumours. Therefore, to complement our technical Worldwide Research News published each Saturday, this blog series will delve into recent developments and provide a more in-depth explanation of what scientists are trying to achieve and how the research may go on to benefit patients.
In the news: Vaccine shown to prolong life of patients with aggressive brain cancer
In a recent Phase III clinical trial, a vaccine known as DCVax®-L was reported to extend the life of patients with glioblastoma (GBM), the most common type of primary high-grade brain tumour in adults. The vaccine was produced by a company called Northwest Biotherapeutics which specialises in developing personalised immunotherapy treatments for solid tumour cancers. The news was reported in The Guardian – read more here.
How does DCVax®-L work?
DCVax®-L works by training a patient’s own immune cells to recognise and attack GBM tumour cells.
As part of their normal function, immune cells circulate the body and seek out cells which are exhibiting signs of distress, such as a viral infection, mutations and others. The immune cells then destroy the affected cell, preventing further infection or damage to surrounding tissues.
Cancer cells, however, are capable of ‘fooling’ the immune system so that they can grow and spread undetected by this natural defence system in a process known as immunosuppression.
DCVax®-L works by training the dendritic cells of a patient’s immune system to recognise the cells that make up the tumour. This enables the immune system to then identify and attack tumour cells helping to reduce its size and hamper progression.
To do this, DCVax®-L takes a 2-3g sample of the tumour and exposes this to the patient’s own immune cells which have been isolated from a blood sample. The cells in the sample learn to recognise unique characteristics of the tumour cells, such as proteins and receptors, also known as antigens. The trained immune cells are then injected back into the patient where they pass on this new information to more cells within the immune system to attack the cancerous cells together.
What does the treatment entail?
The process of creating a batch of newly-trained immune cells takes eight days. The cells are frozen in individual doses, stored centrally and delivered to the physician when required.
A patient will have six intradermal (into the skin) injections in their upper arm over the course of one year. They will then have two injections a year for maintenance after that.
The vaccination protocol would take place alongside current standard of care for GBM patients, which in the UK consists of surgical removal of the tumour followed by radiotherapy and chemotherapy (temozolomide).
How could the vaccine benefit patients?
Published in the phase III trial results of DCVax®-L on 17th November 2022, Northwest Biotherapeutics reported that the median overall survival for a newly diagnosed GBM patient treated with the vaccine was 19.3 months. For a patient receiving standard care only, the median survival was 16.5 months.
In addition, 13% of patients treated with the vaccine survived at least five years from diagnosis, compared to 5.7% in the standard-of-care only group.
However, response to the vaccine differs for different GBM tumour types. For instance, patients with a GBM type which has a methylated MGMT gene who were treated with the vaccine survived on average 30.2 months compared to 21.3 months for the standard-of-care only group.
What stage is the research at now?
DCVax®-L is an emerging treatment and results from a final phase III clinical trial were published in November 2022.
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