Johnson & Johnson (NYSE: [[ticker:JNJ]]) and Medivation (NASDAQ: [[ticker:MDVN]]) shook up the prostate cancer world the past couple years by introducing two important new FDA-approved treatments. Now Cambridge, MA-based Tokai Pharmaceuticals is looking to see if it can go a step further, by combining the best features of each of those drugs into a single pill.
Those two companies, along with Seattle-based Dendreon (NASDAQ: [[ticker:DNDN]]), consume most of the time and attention of those who follow what’s innovative for the treatment of prostate cancer. But privately held Tokai has been quietly sneaking up on the leaders. This year, Tokai is recruiting patients into a 170-patient clinical trial that should give it a sense of whether it has a drug that can compete with the bigger companies.
Tokai, which has raised $57 million since its founding in 2004, has gotten this far through investment from Apple Tree Partners and Novartis Venture Fund. While it toiled away for the last decade in R&D, the hurdles it has had to clear have gotten nothing but higher. Dendreon won FDA approval for its first-of-its-kind immune booster for prostate cancer in April 2010. J&J followed a year with FDA approval of its drug, an oral pill. Then last August, Medivation and its partner Astellas Pharma won FDA clearance for their new pill.
Each of those companies showed in its own company-sponsored clinical trials that it could help men live longer with prostate cancer, with much milder side effects than chemotherapy. Each drug represents an important step ahead in scientific understanding of prostate cancer biology. And each product should be a tough, well-entrenched competitor that Tokai—or any other new entrant—will have to tangle with in the future.
“The bar is really high now in prostate cancer,” says David Miller, president of Biotech Stock Research, which covers the prostate cancer field for investors. “When was the last time you saw a successful late-stage oncology drug that had a lower rate of serious adverse events in the drug arm of the study, compared with the placebo arm? That’s the kind of safety bar [Medivation’s enzalutamide] has set.”
Tokai CEO Martin Williams, not surprisingly, takes an optimistic view. The success of J&J’s abiraterone (Zytiga) and Medivation’s enzalutamide (Xtandi) has provided scientific validation for the path his company has been on for years. While each of those drugs has been an important advance, most cancer needs to be treated with combination therapy because of the propensity tumors have for developing resistance to any one drug.
“The concept for our drug is ‘combination therapy in one pill,’” Williams says. “When you go now to prostate cancer meetings, many of the [key opinion leaders] say the best way to treat prostate cancer is to add enzalutamide to abiraterone and prescribe them together. Then you’re hitting the cancer in multiple different ways. It’s the exact rationale for our drug.”
The concept for Tokai’s drug, galeterone, comes from research done by Angela Brodie and Vincent Njar at the University of Maryland School of Medicine. Brodie, a professor of pharmacology, is best known for her work developing aromatase inhibitors, which are now commonly used for the treatment of breast cancer.
Given that scientists know prostate cancer tumors use male sex hormones for fuel, the scientists sought to cut off the fuel source in three ways. One is by blocking an enzyme called Cyp17 lyase, which is involved in testosterone synthesis, and which J&J’s abiraterone works against. The Tokai drug, an oral steroid analogue, was also designed to block the androgen receptor, which enables cells to process testosterone, and which Medivation’s drug works against. The third way Tokai’s drug is supposed to work is through degrading the androgen receptor itself, so it can’t siphon up whatever trace amounts of testosterone might still be lurking in the blood.
Tokai isn’t the only company
