HAMPTON, NJ (TheStreet) -- Treatment with an experimental, targeted immunotherapy developed by Celldex Therapeutics (CLDX) added to Roche's (RHHBY) Avastin is delaying tumor growth and extending survival in patients with a certain type of recurrent brain tumor, according to interim results from a mid-stage study presented Friday at a medical meeting.
The Celldex cancer immunotherapy used in the study is known as rindopepimut. The company designed the phase II study in recurrent brain tumors to be "exploratory" -- meaning it didn't expect the rindopepimut results to be strong enough for regulatory approval. But the positive data presented Friday, particularly the statistically significant survival benefit favoring patients treated with rindopepimut, has Celldex planning -- cautiously -- for a conversation with the FDA about accelerated approval.
"We're very happy with the interim results, but we're trying to be conservative, so we'll wait for the final data in three to six months. If the results are consistent, we'll meet with the FDA," said Celldex CEO Anthony Marucci.
Like all cancer immunotherapies, rindopepimut is designed to stimulate a patient's immune system to identify and kill cancer cells. In this case, rindopepimut's target is a mutated protein known as EGVRvIII (v3), found in about 30% of primary brain tumors known as glioblastoma multiforme (GBM.) Brain tumors containing high levels of EGVRvIII protein grow more aggressively and are more difficult to treat.
In the phase II "ReACT" study, 72 patients diagnosed with recurrent GBM who had not yet been treated with Roche's Avastin, were randomized into two treatment arms: Rindopepimut (rindo) plus Avastin or a control agent plus Avastin. The study's primary endpoint was progression-free survival at six months, which captures the number of patients still alive with tumors that are not growing following six months of treatment. The study also looked at overall progression-free survival, overall survival and response rate.