Updated to add Vivus obesity drug results.

MOUNTAIN VIEW, Calif. ( TheStreet) -- Vivus ( VVUS) has announced results from two pivotal studies of its obesity drug Qnexa, and the weight loss is impressive.

In the "Equip" study of 1,267 morbidly obese patients, the full dose of Qnexa produced a placebo-adjusted weight loss of 9.4%.

Sixty-seven percent of patients on full-dose Qnexa lost at least 5% of their body weight, compared with 17% of placebo patients.

In the "conquer" study enrolling 2,487 patients (this group included patients who were less obese than those in the Equip study and also included patients with type 2 diabetes) the placebo-adjusted weight loss for Qnexa was 8.6%.

Seventy percent of full-dose Qnexa patients lost at least 5% of their body weight, compared with 21% of placebo patients.

Low- and mid-doses of Qnexa also were tested with good but less robust weight-loss results.

Tolerability was good, with 59% of Qnexa patients completing the 56 weeks of the study.

The drug's safety profile also looks clean, at least according to the press release. No suicide attempts, no suicidality risk or behavior detected in the study. Depression and depressive behavior were low at 2% across the study.

The company also ran a safety study that demonstrated no heart-rate abnormalities in patients treated with Qnexa.

Going by the data in the press release alone, Vivus' Qnexa data looks strong and tops the weight-loss results already seen by competitors Arena Pharmaceuticals ( ARNA) and Orexigen Therapeutics ( OREX).

Opexa's Surge a Headscratcher

Sometimes I watch the intraday moves in a biotech stock and say WTF?!?!

And so it was Tuesday with Opexa Therapeutics ( OPXA), a micro-cap drug stock that soared 270% to $5.66. At one point in the afternoon, the stock was up 350%. More than 57 million shares traded hands on a 9.5 million-share float.

Unreal.

The cause of the buying frenzy was a press release from the company claiming "additional favorable data" from a previously completed phase II study of Tovaxin, a personalized immunotherapy, or "vaccine" for patients with relapsing-remitting multiple sclerosis.

I'll admit to never hearing of Opexa before this weekend, but negative data from this same phase II study of Tovaxin caused the stock to plummet 91% (from $2.34 all the way down to 22 cents) on Sept. 19, 2008.

On Oct. 23, 2008, Opexa provided an update on the Tovaxin phase II study, citing a small subset of multiple sclerosis patients that appeared to benefit from treatment with the vaccine -- or so Opexa claimed. The day after Opexa made this announcement, the stock remained flat at 25 cents.

On November 10, 2008, Dr. Fred Lublin, a multiple sclerosis expert at Mount Sinai School of Medicine, called the Tovaxin data "remarkably unimpressive" at a panel discussion sponsored by the investment bank Rodman & Renshaw.

Opexa offered another update from this same Tovaxin study on March 5 of this year, and once again, the stock did nothing, closing at 28 cents.

So when I see Opexa release more of the same Tovaxin data Tuesday from a subset of patients in a failed phase II study and the stock surge 270%, all I can do is scratch my head, throw up my hands and mutter, "WTF?!?!"

Some Tough Questions for Hemispherx CEO

Let's hope that when Hemispherx Biopharma ( HEB) CEO William Carter takes to the podium this morning at the Rodman & Renshaw Investor Investment Conference, an investor or two in the audience hounds Carter with questions about Ampligen, the company's long-delayed chronic fatigue syndrome drug.

Ampligen is now 107 days past due. The FDA was supposed to issue its approval decision on May 25. At first, Carter claimed FDA telephoned the company requesting "one or two more weeks" to review Ampligen. That was months ago. More recently, Carter suggested that an FDA decision would come "in the fall."

All the while, Carter blames the FDA for the delay, citing its overworked staff and insisting that regulators have not asked the company for any additional data or information about Ampligen.

Does anyone seriously believe that now?

Carter is venturing outside his well-protected cocoon Wednesday to make a rare public appearance at an investor conference. He may have to answer actual questions that aren't pre-screened or otherwise posed by Hemispherx's sycophantic boosters.

It should be interesting.

Antigenics Vaccine Booster Buzz Unwarranted

An FDA advisory panel meets today to review Cervarix, a GlaxoSmithKline ( GSK) vaccine that protects women and teenage girls from virus that causes cervical cancer.

This meeting has nothing to do with Antigenics ( AGEN) and its experimental vaccine adjuvant QS21. Yes, I'm aware of the message board buzz claiming that QS21 is a component of Cervarix and that if the vaccine is approved by the FDA and sold here, Glaxo will pay royalties to Antigenics based on Cervarix sales in the U.S.

Well, sorry to play party pooper, but Glaxo spokesman Jeff McLaughlin told me that the adjuvant used to boost Cervarix is AS04, developed internally at Glaxo. Antigenics and QS21 have no role with Cervarix, he says.

Glaxo is using QS21 in its experimental malaria vaccine, currently in phase III trials.

-- Reported by Adam Feuerstein in Boston
Adam Feuerstein writes regularly for TheStreet.com. In keeping with TSC's editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet.com. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.