Clinical trial data showed that Celldex's brain cancer vaccine is able to improve the chances of brain cancer patients on living longer.

The vaccine, Rintega, which was designed to enable the immune system to recognize and fight against glioblastoma multiforme, was shown to improve the survival rate of patients who were given the vaccine along with Avastin by Roche Holdings by up to two years compared to patients who were just given Avastin.

The results of the trial involving more than 70 patients were presented last Friday during the Society for Neuro-Onclogy's Annual Scientific Meeting. It also helped boost Celldex shares by up to nearly $15.

"The long-term survival benefit observed in this study is unprecedented," said Dr. David Reardon, one of the lead investigators and the clinical director at Dana-Farber Cancer Institute's Center for Neuro-Oncology.

Rintega targets a specific mutation in genes that happen in roughly 30 percent among patients with GBM tumors.

The current average survival rate for patients with these forms of recurring GBM tumors is around nine months, but with the Rintega and Avastin combination, at least 32 percent of brain patients survived after 18 months, compared to the 13 percent of the patients who only received Avastin.

Celldex studies also showed that Rintega was able to meet its main goal of helping patients have higher chances of surviving for six months without their conditions worsening.

Rintega has been granted by the Food and Drug Administration a breakthrough therapy designation earlier this year.

Celldex added that the interim results from the study to assess the effectiveness of Rintega on newly diagnosed patients with GBM tumor will be available by early next year.

Researchers said that this was the first time a form of immunotherapy was able to improve survivability of GBM patients and the first vaccine based cancer treatment shown to actually improve cancer patient survival rate and maybe even quality of life.

"Most striking perhaps is that not only are patients living considerably longer, they are also living better, with minimal side effects and a reduced need for steroids," Reardon said.

GBM tumors are formed astrocytes, one of the supportive nervous system tissues, found in the brain and spinal cord. These tumors are usually malignant and can easily invade normal brain tissue, but also rarely migrate outside of the nervous system.