Jennerex Shows Survival Edge for Liver Cancer Patients in Small Study of Anti-Tumor Virus
San Francisco-based Jennerex Biotherapeutics isn’t ready to show results from its tumor-fighting virus at the meeting that attracts all the big boys and girls in the cancer drug business, but today it is unveiling some provocative results that suggest it may help liver cancer patients live longer.
Jennerex’s data is still preliminary, and comes from a small study of just 30 patients that began in early 2009. More follow-up is required before any firm conclusions can be drawn, but it’s intriguing nonetheless. Patients with advanced liver cancer who got a low dose of Jennerex’s engineered anti-tumor virus, JX-594, lived for a median time of about 6.5 months, which was in line with expectations. What’s interesting is that statisticians haven’t yet been able to calculate the median survival time for the high dose because not enough have died yet after a median of one year of follow-up, according to Jennerex CEO David Kirn. Eight patients on the high dose are still alive for at least a year, and some are still being followed up for two years, he says. For comparison, patients with this same prognosis are generally expected to live a median time of about 10.5 months when taking sorafenib (Nexavar) from Bayer and Onyx Pharmaceuticals.
The findings from this study, called HEP007, are being presented today at the American Society of Gene and Cell Therapy in Seattle. It’s a small meeting compared to the big kahuna of the cancer drug development world—the American Society of Clinical Oncology, which is holding its annual meeting in Chicago in a couple weeks. Jennerex’s data wasn’t ready in time for ASCO’s data submission deadline in January, so it had to skip ASCO, Kirn says. But he adds that final results from this small trial, including the survival readout for patients in the high dose, will be ready for one of the big medical meetings in the fall, Kirn says.
“We will need to further confirm it, but this is the first time in medical history that a viral or gene therapy has shown a survival advantage in a randomized, controlled study,” Kirn says. “It’s quite a stunning survival benefit.”
I wrote about the Jennerex drug back in February, shortly after Kirn offered an earlier peek at how this trial was unfolding. The program is sure to attract interest on scientific grounds, since it’s one of a handful of treatments in the works that uses viruses that are genetically modified to replicate strictly inside tumors. These injectable viruses are designed to burrow into tumors, where they replicate very fast, causing the cancer cells to burst. The Jennerex treatment is also made to target the blood vessels that feed the tumor, and send signals that alert the immune system to track down any residual cancer cells that might have been able to evade the virus. Many companies-Onyx Pharmaceuticals and Cell Genesys-have tried similar approaches and no one has yet won an FDA approval. But Amgen stirred some renewed interest in the field earlier this year when it agreed to pay as much as $1 billion to acquire Woburn, MA-based BioVex.
There’s plenty of room to doubt the data that Jennerex is presenting today. The primary goal of the study was to see if the high dose of the treatment is any better than the low dose at slowing down the spread of tumors, Kirn says. Survival time was a secondary goal. And, on the primary goal, Kirn says the data was “hard to assess” because the treatment caused swelling and an immune reaction around the tumors that became a confounding factor for radiologists. And, of course, the FDA and physicians won’t judge a drug’s ability to extend lives on a small study of just 30 patients. So far, the side effect profile is clean—Kirn says patients are experiencing flu-like symptoms that last a couple days.
But Jennerex is hopeful that this study is tantalizing enough to help provide a lift as it heads into a more rigorous trial, known as Traverse, which will seek to enroll 120 patients, starting before the end of September, Kirn says. That study will be designed so that the primary goal is overall survival, the gold standard in cancer drug development, and to randomly assign patients to either get a high dose of the Jennerex drug or a placebo.
If the Traverse study can come close to matching what was seen in this smaller study, then you can bet it will be time to take the stage at ASCO. “At the end of day for this drug, it’s all about survival,” Kirn says. “That’s all that matters.”