Have you been diagnosed with a brain tumour? Order your free information pack.

Tocagen’s ‘breakthrough’ gene therapy trial will continue

After undergoing an interim analysis, a phase 3 clinical trial called Toca 5 that tests a gene therapy in patients with recurrent brain cancer, will continue

After undergoing an interim analysis, a phase 3 clinical trial called Toca 5 that tests a gene therapy in patients with recurrent brain cancer, will continue

The Toca 5 trial is one of the largest randomised trials conducted in patients with high-grade gliomas – aggressive, fast-growing tumours that have a high chance of recurrence.

This international, multi-centre clinical trial is testing a gene therapy, which consists of two drugs: Toca 511 and Toca FC, in patients with recurrent high-grade gliomas.

Tocagen, the company leading the trial, announced that the Independent Monitoring Committee, an independent group responsible for the safe monitoring of trials, recommended that the trial continue without any changes.

This is encouraging news, especially following the disappointing news of both the Nivolumab and Deputax-M trials.

However, researchers won’t be able to say for sure if this treatment will benefit patients until the final analysis has been done, which is due at the end of this year when the trial is scheduled to finish.

About Toca 511 and Toca FC

The gene therapy being tested in the Toca 5 trial consists of two drugs, called Toca 511 and Toca FC. The two drugs work together, with Toca 511 containing the protein, which has the ability to convert Toca FC to the anti-cancer drug, 5-fluoracil, in the body.

Toca 511 is given to the patient first during surgery by injecting into the cells surrounding where the tumour used to be. Toca 511 seeks out tumour cells, infects them, and gives them each a gene which makes a protein called CD.

Toca FC is then given to the patient in the form of a tablet, every day for seven days, starting six weeks after surgery and repeated every six weeks.

The drug is carried in the bloodstream, across the blood-brain barrier and enters the cells. When CD, which is only produced by the tumour cells, comes into contact with Toca FC, it converts the Toca FC into an anti-cancer drug, called 5-fluoracil, and kills the tumour cell from the inside.

The outcomes from the phase 1 clinical trial testing the safety of this gene therapy were positive and the treatment was well-tolerated in the trial participants.

Based on these positive outcomes, the therapy was granted the ‘breakthrough’ designation by the US Food and Drug Administration (FDA), which meant that the therapy will get reviewed faster when the results become available.

In addition, the FDA also agreed to extend the phase 2 clinical trial into a phase 3 study, which means that if the trial is successful, the therapy will be made available for patients sooner.

However, before getting approval, all new drugs undergo rigorous testing to prove they are safe and more effective than the current standard treatment available to patients.

One way to demonstrate this is through improving overall survival, which refers to how long people live after receiving treatment.

We eagerly await the final results from this trial and will provide an update as soon as the results become available.

If you require additional information, please contact the Research Team at research@thebraintumourcharity.org.