The drugmaker says is too early to predict with any certainty how long it will take to resolve its manufacturing troubles which started in May with a warning letter from the US Food and Drug Administration (FDA) about its Puerto Rico plant and culminated last month in the agency expressing reservations about stability data regarding the manufacturing method of Lybrel, its low-dose oral contraceptive which, if allowed in the US market, is expected to reach annual sales of $400m (€320m) in 2009.
The biggest challenge for Wyeth is addressing the FDA's concerns arising from the good manufacturing practice (GMP) violations that were discovered between November and December 2005 during the agency's inspection of the company's manufacturing facility in Guayama.
These violations resulted in a strongly-worded warning letter from the FDA to which Wyeth responded and has been working since to ensure compliance and avoid site closure or other severe action.
Although the New Jersey-based company claims that the production at Guauama of most of its drugs, like the painkiller Advil and anti-depressant Effexor, has not been affected, Wyeth decided to put a hold on the production of its oral contraceptives Triphasil and Alesse while it works on the issues identified by the FDA.
"We have brought in a consultation firm to advise us on GMP matters, this is a pretty complex issue and we will vigorously strive to resolve it as quickly as possible," Wyeth spokeswoman Natalie de Vane told In-PharmaTechnologist.com.
"In the mean time Triphasil has run out at wholesale level while Alesse will also run out soon."
Triphasil played a prominent role in the FDA's grievances after a contamination in batches of tablets was detected in June 2005, leading to the voluntary recall of 20 lots of the pill from wholesale distributors almost a year later and the subsequent end in production.
Wyeth will not disclose how much Triphasil's and Alesse's absence from the market will cost its oral-contraceptive business which has been already suffering in recent years, with sales falling 11 per cent to $525.3m in 2005.
Meanwhile Wyeth is working to get Lybrel approved in 2007 by addressing manufacturing items outlined in the FDA's approvable letter last month and is bracing for a preapproval inspection at the Guayama site where the drug will be made.
Thanks to its low labour costs and its rich pool of expertise, Puerto Rico is a popular destination for drugmakers, yet troubles at Guayama have a cast a long shadow on the pharmaceutical industry's tropical manufacturing paradise.
Nevertheless, Wyeth's other manufacturing plant in Puerto Rico, located in Carolina, is not facing similar problems, and in a conference with financial analysts, Wyeth CEO Robert Essner stressed his company has made restoring normality in manufacturing operations a top priority.
He also pointed out that the safety or efficacy of Wyeth's drugs is not at stake and that fixing problems at Guayama shouldn't require substantial changes to the plant's infrastructure.
The company is hoping to have resolved all manufacturing issues by the end of 2006.