US pharmaceutical major Wyeth has raised its 2006 full-year 2006 guidance on the back of a solid first-half performance and the success of key pharmaceutical products in its portfolio such as the antibiotic Tygacil (tigecycline) and meningitis vaccine Prevnar.

Wyeth now expects to post diluted earnings per share of $3.12-$3.18, excluding any potential restructuring charges from the company's ongoing review of business processes and systems.

The EPS forecast assumes, among other things, the passage of the R&D tax credit legislation that is currently being debated by the US Congress and that the credit will be made retroactive to January 1, 2006.

The US drugmaker also said that it was entering a major new phase of product introductions, with seven new drugs due to be filed for approval in the USA over the next 18 months.

One of these, Pristiq (desvenlafaxine succinate; DVS-233), is intended as a replacement for Wyeth’s blockbuster Effexor (venlafaxine) which had sales of $3.5 billion last year but is facing the threat of generic competition. But the firm is still remaining a little tight-lipped on this product, which is delayed at the Food and Drug Administration while studies look at lower doses. The key objective is to find a dose that maintains efficacy while reducing the drug’s tendency to cause nausea.

Another key pipeline product is Viviant (bazedoxifene), a selective oestrogen receptor modulator for the prevention of osteoporosis and menopausal symptoms, that has been filed for approval in the USA. If approved, bazedoxifene would compete with Eli Lilly’s Evista (raloxifene), and Wyeth believes its profile could make it a potent rival with peak sales potential of $2 billion or more.

Wyeth also plans to combine bazedoxifene with its established hormone replacement therapy Premarin (conjugated oestrogens) in a new product, Aprela, that could be filed for approval next year.

A new formulation of Prevnar, targeting additional pneumococcal serotypes, could be filed in early 2009 and bolster a franchise that could bring in sales of $3 billion by 2010, according to Essner.

On the downside, bifeprunox, a drug for schizophrenia, proved to be less effective than rivals in late-stage clinical trials, but was also much less likely to cause metabolic disturbances such as weight gain, high blood lipids and insulin resistance. This profile means that it could still find a role in patients who can’t tolerate other antipsychotics, said Wyeth, which plans to submit it for approval in the USA this month.

Other late-stage pipeline candidates include: new oral contraceptive Lybrel (levonorgestrel/ethinyl estradiol), designed to reduce symptoms associated with the menstrual cycle; cancer drug Torisel (temsirolimus), which works by blocking new blood vessel formation in tumours; and opioid analgesic methylnaltrexone.

Wyeth's chief executive, Robert Essner, noted that this revised EPS figure represents an increase of 13%-16% over 2005 EPS of $2.75 again excluding the restructuring charges associated with Wyeth's productivity initiatives, excludes the income tax charge recorded in connection with the repatriation of foreign earnings and includes the pro forma effect of expensing stock options.