Total revenues for the second quarter were down by over $50m compared to Q2 2006, and half year figures showing revenues of $450m compared to $477.8m for the equivalent period last year.

Product revenues for the quarter dropped a hefty 22 per cent compared to last year, reaching just $190.8m. The main culprits for this decrease were lower revenues from the company's sales and marketing business, Biovail Pharmaceuticals Canada, and the introduction of generic competition for the firm's antidepressant product, Wellbutrin XL (bupropion hydrochloride) at the end of 2006.

Sales of Wellbutrin XL for the quarter were $53m, compared to $114m for Q2 2006. First quarter sales of the drug were slightly healthier, so figures for the half year only showed a $64.5m drop compared to last year.

In December 2006 a generic version of the 300mg strength of the Wellbutrin product was launched on the market, significantly eroding the company's revenues and causing the steep decline in sales.

However, in a bid to protect the Wellbutrin franchise, the company has entered into a comprehensive settlement agreement with a number of generic pharmaceutical companies (with certain exceptions) to delay the possible introduction of a generic version of the 150mg dose until 2008.

Biovail has been actively pursuing other means of protecting the Wellbutrin family of products, largely focused around the development of certain other bupropion salt compounds that could extend the line and offer advantages over the existing Wellbutrin products.

However, last month the company was dealt a blow when its key bupropion compound BVF-033, currently in development, was the subject of a non-approval letter by the US Food and Drug Administration (FDA).

BVF-033 is a new bupropion salt product intended as a once-daily option for the treatment of depression. Biovail believes that BVF-033 could offer a superior safety profile to bupropion hydrochloride, the active ingredient in the successful Wellbutrin XL product.

Biovail's bupropion salt formulation was also intended as a platform for a bupropion combination product, BVF-045. The combination product combines two anti-depressants which between them target serotonin, dopamine and norepinephrine, and could offer benefits in terms of faster onset, better efficacy at lower doses and an improved side effect profile.

However, plans for BVF-045 necessarily hinged on approval of BVF-033.

Original plans were to launch the BVF-033 product in the fourth quarter this year, and try to redirect the flow of cash away from the generic Wellbutrin XL manufacturers and back to Biovail coffers with the new and improved product.

However, the FDA ruling means that an extra eight months could be added to the BVF-033 timeline, giving the generic players a pleasant stay of execution while the company struggles with the regulatory decision.

Biovail is due to meet with the FDA next Tuesday to discuss the agency's non approval letter and the way forward for BVF-033.

Other products in Biovail's portfolio, however, have been performing more strongly, helping to offset the declines caused by generic competition.

Pain treatment Ultram ER (tramadol) was launched in February 2006, and the company recorded revenues of $19.6m in the second quarter this year, compared with $0.9m last year (negatively impacted by a $7.8m return provision related to a June 2006 recall).

Zovirax (acyclovir) was another strong performer, with sales for the quarter up 21 per cent year on year to reach $35.2m.

Restructuring efforts implemented at the end of last year have paid off, according to the company, helping drive down costs and keep the company's finances in hand.

For the remainder of 2007 the company intends to continue investing in product development, having today also announced a deal with an undisclosed pharma partner for the development, manufacture and marketing of a novel product for the treatment of "a prevalent sexual dysfunction."

The product would allow the company access to the multi-billion dollar sexual dysfunction market, with a new drug application (NDA) tentatively anticipated in mid-2009.