Written by JANE ALLIN
Pfizer, the world’s largest drug maker, has announced the withdrawal of its new drug application (NDA) for Fablyn® a selective estrogen receptor modulator (“SERM”) for the treatment of both osteoporosis and selected consequences of menopause. As with other SERMs, Fablyn® has been shown to have significant side-effects which contraindicate widespread use.
In September of 2005, Fablyn® was rejected by the FDA due to elevated risks of uterine cancer and then in January of 2009 failed to win US approval due to increases in combined fatalities from all types of cancer in addition to strokes.
Pfizer said that it is exploring strategic options for Fablyn®, including out-licensing or sale.
In the EU, Fablyn® received approval from the European Commission in February 2009, and Viviant® under the trade name Conbriza®, for the treatment of post-menopausal osteoporosis in women at increased risk of fracture in April 2009.
What has this got to do with horses?
Meanwhile, other potential candidates for the treatment of post-menopausal osteoporosis are awaiting approval – Pfizer’s Viviant ® and Pfizer/Ligand Pharmaceuticals’ Aprela®. Viviant® is a “SERM” and Aprela® is Viviant® + Conjugated Equine Estrogens (CEEs) as iFH called attention to in an earlier article: “Aprela®: The Lesser Evil?
In keeping with other SERMs, Viviant® is not without issues and its approval for sale has been delayed by the FDA citing concerns pertaining to data collection and reporting and elevated incidence of stroke and venous thrombotic events. With any luck, these findings in conjunction with the inherent risks of CEEs and now the retraction of Fablyn’s® NDAs will jeopardize the FDA’s approval of Viviant® and Aprela® in North America.
And, what about Pfizer/Wyeth’s recent announcement that they will seek to resize the local Canadian PMU industry which will see the number of equine ranches dwindle from the current 64 to as few as 25?
The next couple of years may prove to be an interesting storyline for Big Pharma and the PMU mares and foals!