Celldex brain tumor vaccine shows well at ASCO

June 4, 2015

A blog post by Max Wallace, CEO of ABC2

We have some positive brain tumor treatment news out of the ASCO meeting.

As you know, we have long been interested in the use of vaccines to treat brain cancer. One of the projects where we provided early funding was work at Duke by John Sampson and Duane Mitchell. It is a vaccine that targets GBM tumors that have a mutation in the Epidermal Growth Factor Receptor (EGFR) called EGFRvIII. This mutation occurs in about 30% of GBMs and patients with this mutation typically have a worse prognosis than the overall glioblastoma population, including poor long-term survival. Duke eventually licensed the vaccine technology to a company, Celldex, in order to move it through the clinical trials process and then bring it to commercialization.

At Celldex, the vaccine has become known as Rintega. We have followed Rintega as it has made its way through preclinical development and the first two stages of the FDA clinical trial process. Dr. Tom Davis, the Chief Medical Officer at Celldex, has been a guest at our scientific meetings.

A number of the researchers we work with have been involved in the ongoing Rintega trials, including Dr. David Reardon, who is the Clinical Director of the Center for Neuro-Oncology at Dana-Farber Cancer Institute and President of the Society for Neuro-Oncology. Dr. Reardon was the lead investigator of the most recent Rintega study known as ReACT.

This weekend, at the American Society of Clinical Oncology (ASCO) meeting in Chicago, Dr. Reardon presented positive results from the ReACT study -- a randomized, double-blind Phase 2 study of Rintega in patients with EGFRvIII-positive, recurrent glioblastoma. The primary endpoint of the study, progression-free survival at six months (PFS6) was met, and Rintega demonstrated a clear advantage across multiple other clinically important endpoints including overall survival (OS), long-term progression-free survival, objective response rate (ORR) and need for steroids.

Recurrent EGFRvIII positive patients present major treatment challenges, having failed on the standard of care treatment regimen of surgery, radiation and Temodar. Avastin therapy is often the next step for such patients. This study compared Rintega used with Avastin to Avastin used with a placebo compound. As Dr. Reardon notes, the results are impressive for an especially difficult GBM population and it looks as if Celldex will try to use these results to obtain accelerated approval This would be good news for our patient population and also nice validation of our funding efforts.

Here is a link to an article that goes into greater detail on the ReACT trial results: http://www.thestreet.com/story/13167195/1/asco-15-celldex-immunotherapy-maintains-survival-benefit-for-recurrent-brain-tumor-patients.html and here is a link to the company’s press release. http://ir.celldex.com/releasedetail.cfm?ReleaseID=915592

FYI: Note that the PFS and OS numbers cited in the article and the press release are measured from the time of administration of the study compounds, not from initial diagnosis. People often talk about average GBM survival in the range of 8-12 months. In light of that, these numbers don’t necessarily look that impressive. Remember, though, that there was a first stage treatment here before recurrence, which is when these trials started and began measuring time.