Arena Obesity Drug Passes Second Trial, Aims to Sell Safe Option for Millions of People

9/18/09Follow @xconomy

Arena Pharmaceuticals can breathe a sigh of relief. Twelve years of work and $1 billion invested in drug development isn’t going down the drain. The San Diego-based company is reporting today that it has passed the second big clinical trial it needs to win FDA approval to sell an obesity drug that has potential to be used by millions of people, and which could generate billions in sales.

The long-awaited results from Arena (NASDAQ: ARNA) from a trial of 4,008 patients essentially confirm what the company found in a previous study of 3,182 patients back in March. The drug met at least one of the FDA’s benchmarks for effectiveness as an obesity treatment and was found to be safe and well-tolerated. Arena plans to present all the nitty-gritty details next month at The Obesity Society meeting in Washington D.C., and plans to ship off an application to the FDA by the end of this year.

“We’re excited. We’ve accomplished what we set out to accomplish,” says Jack Lief, Arena’s CEO.

Obesity is one of the nation’s biggest public health problems, with two-thirds of the U.S. population considered overweight. As I described in a story Monday, drug companies know the winner in this category might dominate the biggest pharmaceutical market ever. In our couch-loving, junk-food eating culture, health officials say obesity often leads to diabetes and a raft of other costly health problems. Yet Big Pharma has been gun shy about this market opportunity since Wyeth was burned by the multi-billion legal payments related to the heart damage that patients suffered from the fen-phen drug in the 1990s. Two years ago Sanofi-Aventis failed to win approval for an obesity drug that was linked to rare cases of suicidal thinking. If any of the new contenders can assure the FDA their drug is truly safe, obesity drugs will again become a popular culture phenomenon, and will likely get pitched as a pre-emptive cure-all for illnesses related to obesity—like diabetes, high blood pressure, high cholesterol, and depression.

Although Big Pharma has been cautious, Arena and other biotechs are in hot pursuit of the market. San Diego-based Orexigen Therapeutics (NASDAQ: OREX), Mountain View, CA-based Vivus (NASDAQ: VVUS), and San Diego-based Amylin Pharmaceuticals (NASDAQ: AMLN) have all shown encouraging results from mid-or-late stage clinical trials. Vivus and Arena appear to be ahead in the race, with stated goals of sending their applications to the FDA by the end of this year. Orexigen plans to turn in its FDA filing in the first half of 2010, while Amylin is still in mid-stage clinical trials.

So what did Arena really learn from this huge clinical trial coming out today, known as Blossom?

Patients in the Blossom study were followed for one year after they were randomly assigned to get either a twice-daily pill, a once-daily pill, or a placebo. Patients on the twice-daily Arena treatment lost the most weight—an average of 5.9 percent of their body weight, compared with 2.8 percent on placebo. That finding, by itself, isn’t good enough to pass muster with the FDA, because it typically wants an obesity drug to show an extra 5 percentage points of weight loss on average. The difference is in the same ballpark, however, as what Arena showed in the so-called Bloom study earlier this year, in which lorcaserin was about 3.6 percentage points better than placebo.

So why does Lief say he’s excited? Vivus produced what it called “unprecedented” effectiveness, (and wowed investors last week) when it reported its drug had a 9.4 percentage point advantage over a placebo in a separate clinical trial.

It turns out that obesity drug developers have more than one way to impress the FDA, and Arena passes that test. The Blossom study being reported today shows that 47 percent of patients on the twice-daily Arena drug lost at least 5 percent of their body weight, while just 25 percent did that well in the placebo group—and the FDA has said it considers such a drug “effective” if it can help about twice as many people lose that much weight as a placebo.

Particularly since the FDA will require a squeaky-clean safety profile for an obesity drug that might be taken by millions of people without an imminent life-threatening disease, safety is critical. Based on the Blossom results, Arena has good reason to breathe a sigh of relief.

That’s because the company’s drug is designed to work in a similar way as Wyeth’s fen-phen combination drug did in the 1990s, before that drug was pulled off the market over damaged heart valves. The Arena drug is supposed to be more specific—to interact with an enzyme in the brain that controls feelings of fullness—without hitting a similar enzyme on the heart that led to the undoing of fen-phen.

What Arena has learned, by looking at sophisticated echocardiogram images of the heart in more than 7,000 patients, is that its drug doesn’t appear to damage heart valves like fen-phen. The most common adverse events reported in the trial were upper respiratory tract infections, stuffy nose, and headache, although only a few more patients reported those effects on the drug versus the placebo.

As I described in a preview about these clinical trial results, Arena is trying to play up its drug’s clean safety profile as an advantage. It’s still early days in this face-off, but it appears that the rivals are starting to find their niches, with one likely to help people lose the most weight (Vivus), another that helps to help treat the related ailments that stem from obesity (Orexigen), and one that positions itself as the safe alternative for the masses (Arena).

Lief made it clear to me that Arena has its cross-hairs set on the thousands of primary care physicians in the U.S. who are on the front lines of the nation’s obesity epidemic. Arena will need help from a partner with serious marketing muscle to reach this vast audience of doctors and patients, but Lief sounds like he has TV commercials dancing through his head already. What it basically boils down to is a pitch that goes like this: Arena’s drug won’t hurt, and might help.

“We think we can change the way primary care physicians treat weight loss,” Lief says.

He adds: “It’s not just about efficacy, it’s about safety as well. Because our drug is so safe, we think we’ll address the broadest patient population for weight loss.”

Arena will host a webcast at 8 am Eastern/5 am Pacific time today to discuss the results in greater detail with investors.

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