Edward John Allera, chairman of the Buchanan Ingersoll & Rooney's FDA/Biotechnology Section and managing shareholder of the firm's Washington, D.C., office, was quoted in a November 6, 2009, article published by Pharmawire. The article, titled "Vivus, Orexigen, Arena must show both categorical and mean weight loss for FDA approval; decrease in blood pressure not required — experts," discussed the FDA's draft guidance titled "Guidance for Industry Developing Products for Weight Management," issued in February 2007.

As explained, "According to the document, a product can be considered effective for weight management if after one year of treatment either of the following occurs: The difference in mean weight loss between the active product and placebo-treated groups is 'at least five percent' and is statistically significant; or the proportion of subjects who lose greater than or equal to five percent of baseline body weight in the active-product group is 'at least 35 percent is approximately double the proportion in the placebo-treated group,' and is statistically significant."

Many experts believe the draft guidance will require drugs Vivus's Qnexa, Arena's lorcaserin, and Orexigen's Contrave to demonstrate both mean and categorical weight loss.

Allera weighed in saying, "As primary efficacy endpoints, the draft guidance suggests that the FDA wants to see both an improvement in categorical and mean weight loss." He went on to say, "In general, the FDA wants to see an improvement in cardiovascular parameters, according to each patient's bloodwork. Showing a decrease in blood pressure is probably not critical for these drugs, as long as other parameters, such as reduction in LDLs and increase in HDLs, are shown."