Synta Melanoma Drug Fails Disastrously in Clinical Trial, As Patients Show Higher Death Rate

Synta Pharmaceuticals reported some disastrous news this afternoon. The Lexington, MA-based biotech company (NASDAQ: SNTA) said it has halted a clinical trial involving more than 630 cancer patients because a greater number of people died after taking the company’s experimental drug along with traditional chemotherapy, compared with those who got the chemo alone.

The trial, called Symmetry, enrolled patients with a deadly form of skin cancer that had spread through the body, metastatic melanoma. They were randomly assigned to get Synta’s elesclomol in a once-weekly  infusion with paclitaxel chemotherapy, or paclitaxel alone. Members of an independent safety monitoring board identified safety concerns, as well as a greater number of deaths, among people who got the Synta drug. The absolute number of deaths in both study groups, or how much shorter survival times were for patients in the drug group, wasn’t disclosed. But the finding was apparently so alarming that Synta is closing down other ongoing trials of the drug for patients with prostate cancer, and others going through a preliminary dose-ranging study.

This news is devastating for Synta, which has no products on the market, and was hopeful that elesclomol would represent a pioneering advance for cancer. As I described in a feature story last month, the treatment was designed to amplify the amount of oxidative stress in the body, which is thought to nudge cancer cells past a breaking point in which they trigger a self-destruct mechanism. This same effect was thought to have little impact on healthy cells, because they contain lower levels of these reactive oxygen molecules, and they have a natural ability to send in anti-oxidants to keep them in balance, said CEO Safi Bahcall, in an interview at the time. People at the company were excited, he said, by the opportunity to build on a strong set of data from Phase II, which suggested elesclomol could keep tumors from spreading for 3.7 months, compared to 1.8 months for those on traditional chemo alone.

“Our first concern is for the safety of patients, and therefore we acted promptly to halt the SYMMETRY trial once it was evident that there were serious safety concerns,” said Eric Jacobson, Synta’s chief medical officer, in a statement. “We are enormously disappointed for melanoma patients, particularly because there are so few treatment options available. We will be working hard over the next several weeks to analyze and better understand the results from this trial.”

In my interview with Bahcall last month, he was bullish about this drug and going through whirlwind meetings with investors who wanted a piece of it. “When we have positive data, it’s going to be an explosion not only in the treatment of melanoma but also in the science,” Bahcall said. “This opens up a whole new field of science.”

Now that the drug has failed, Bahcall says it won’t kill the company. It had about $65 million to $70 million in cash left at the end of 2008. “While this is a considerable setback, Synta has both the resources and a diverse pipeline of novel drug candidates that will allow us to continue to develop our oncology and anti-inflammatory programs,” Bahcall said.

Synta will discuss the results in greater detail in a conference call with analysts at 5:30 pm Eastern today. If there’s a need to update with more information, we will.

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