New York, Jun 13 (IANS): An experimental vaccine has shown promise in delaying the return of deadly brain tumour and also extending the average survival rate from 15 to 26 months, media reports said.

The vaccine, SurVaxM developed by US biotech company MimiVax, targets a protein found in tumours called survivin, CNBC reported.

When injected into the patient, the jab stimulates the production of T-cells -- body's immune system -- which then attack survivin, vital to survival of glioblastomas. The attack destroys the protein, reducing the size of tumours or preventing its growth.

Glioblastoma is one of the most fatal and treatment-resistant cancers, which can result in death in six months or less, if left untreated.

It makes up nearly half of all malignant brain tumours and has a five-year survival rate of 6.8 per cent.

Traditional treatment of glioblastomas typically involves surgery, chemotherapy and radiation. However, unless every cancer cell is eliminated, the tumour often comes back.

"SurVaxM works by training the immune system to target and attack the cancer cells, so if they do return, the body can pick them off, preventing a new tumour from growing, Michael Ciesielski, the CEO of MimiVax, was quoted as saying.

According to Honggang Cui, Associate Professor of chemical and biomolecular engineering at Johns Hopkins Whiting School of Engineering, the approach is "promising".

"This could bring hope to people who are impacted by GBM," he was quoted as saying.

The vaccine consists of four doses, spread out over two months, followed by a booster dose every two months. Participants in the trial will either get the real vaccine for each shot or a shot of a placebo every time. Participants will also get a brain scan every two months to monitor for signs of progression.

After the success of the early clinical trial, the drugmaker is enrolling patients in a larger trial of up to 270 patients from the US and China, the report said. In addition, the company will also examine the vaccine on other cancers including multiple myeloma and neuroendocrine tumours.