OncoGenex Stays in Prostate Cancer Fray, After J&J, Medivation

1/27/12Follow @xconomy

Prostate cancer was once a backwater for innovation, but suddenly it’s become one of the most competitive battlegrounds in all of biotech. And one of the darkhorses in this race, Bothell, WA and Vancouver, BC-based OncoGenex Pharmaceuticals, is getting ready to show next week whether it has another contender in the pipeline.

OncoGenex (NASDAQ: OGXI) is preparing to release interim results next week from a clinical trial that could offer a hint of effectiveness of a prostate cancer drug called OGX-427. If OncoGenex can show in this 72-patient study that its compound is slowing the spread of tumors, and lowering prostate-specific antigen (PSA) scores, then it could be in position to run a more meaningful trial that asks whether it can prolong lives, or work well in combination with other therapies. The preliminary data are expected Feb. 2 at the American Society of Clinical Oncology’s Genitourinary Cancers Symposium in San Francisco.

Results from this trial, and another study among patients with bladder cancer, mean a lot for OncoGenex during what has been a long period without much big news for investors and researchers to chew on. The company is now enrolling 800 patients into a pivotal study of its lead prostate cancer drug, custersin, but expects it will have to wait until the fourth quarter of 2013 to find out whether that treatment can extend lives of prostate cancer patients. While OncoGenex makes that long slog through development, it has seen companies like Dendreon, Johnson & Johnson, Medivation, Bayer, and Exelixis continue to jockey for position at various stages of therapy, each with distinct modes of treatment, for men with prostate cancer. The disease kills about 30,000 men in the U.S. each year.

“A lot of focus for us is on custersin, but while that’s going on, we continue to mature our OGX-427 data,” Michelle Burris, OncoGenex’s executive vice president of operations, said during a meeting at the JP Morgan Healthcare Conference earlier this month. While she notes the second OncoGenex drug has shown encouraging ability to work on its own in small studies, she acknowledged it will have to find a niche in a competitive landscape—and says that it can. “It plays nice with a number of different therapies,” she says.

Michelle Burris, OncoGenex's executive vice president of operations

The OncoGenex drug, given through an IV infusion, is designed to work by blocking a biological target known as heat-shock protein 27 (Hsp27). That protein is believed to play a role in helping cells survive under stressful conditions. It’s supposed to help stabilize proteins that keep cells from committing suicide. By inhibiting its activity, you could in theory allow cancer cells to naturally undergo the cell death (apoptosis) process. But there’s also another mechanism of hsp27 that researchers find interesting. It is thought to work as a “chaperone” molecule that helps shuttle in male hormones that fuel prostate tumors.

Researchers believe that could be useful because hormone deprivation therapies have long been standard treatment for prostate cancer, and patients end up developing resistance over time. Two new hormone-blocking therapies, Johnson & Johnson’s abiraterone (Zytiga) and Medivation’s MDV-3100, have both been shown in clinical trials to extend lives of men who resist conventional treatments by blocking male androgen receptors in a different way. OncoGenex’s bet is that even while those drugs are doing their thing, Hsp27 is operating as a chaperone that allows some residual androgens into the tumor, which help provide it with some sustenance.

This theory of cancer biology is being tested in a trial sponsored by the British Columbia Cancer Agency, and led by Kim Chi. The key study enrolled 72 patients with prostate cancer that resists the usual hormone-deprivation therapy, and randomly assigned them to get ordinary prednisone or prednisone plus the OncoGenex drug, OGX-427. Since the Hsp27 target is found in many different cancers, the company is also testing the drug in other settings, and also expects to see results from an early-stage study of bladder cancer patients.

Not many on Wall Street appear to be expecting much from these small studies. “Should Phase II data appear promising, we will incorporate OGX‐427 into our valuation,” wrote Katherine Xu, an analyst with William Blair, in a Jan. 24 note to clients.

Given that OncoGenex is a small company, with 36 employees and about $69 million in cash according to its last financial statement, there are limits to how fast it can move ahead with more than one drug in clinical trials.

Burris says OncoGenex has enough money to operate the business into 2014, at which point it expects to see the pivotal survival results from its lead drug candidate, custersin. But she also recognizes that’s a long time for investors to wait around for a single make-or-break company event. So OncoGenex will have to decide how aggressively to move ahead with the OGX-427 development plan, based on what it hears from investors and researchers next week in San Francisco, and based on the resources it has to work with. We’ll have a clearer sense of where the program is going next Thursday.

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