The Drugs Technical Advisory Board (DTAB), the highest body under the Union Health Ministry on technical matters concerning the pharma industry in the country, will re-examine the controversial drug letrozole which is indicated for sub-fertility in young menstruating women in the country. The DTAB is meeting on November 9.

Letrozole, a research molecule of Novartis, is approved for use in cases of breast cancer in postmenopausal women all over the world.

Ever since the Mumbai-based pharma company Sun Pharmaceuticals was given the marketing nod for letrozole by the Drug Controller General of India (DCGI) a couple of years ago, there was an outcry from the medical fraternity in the country against the drug as there were reports that its use in women of child bearing age is strictly prohibited elsewhere in the world due to severe side effects such as estrogen deprivation, ovarian atrophy, uterine atrophy, increased incidence of foetal malformations, foetal resorption and foetal death.

In view of the increasing criticism against the drug in the country, the DCGI decided to leave the matter to the consideration of the DTAB. The DTAB is headed by the Director General Health Services (DGHS), and its members included eminent persons in the field such as DCGI himself, Director CDRI Kolkatta, director CDRI Lucknow, etc.

Letrozole is one of the items in the agenda of the DTAB meeting on November 9 and it will review whether to allow the drug in the country to treat sub-fertility in young menstruating women or not, DCGI Dr Surinder Singh said.

When the drug was launched in the country, there were allegations that the approval was granted in flagrant violation of Indian safety laws. As per norms, even an old drug when used for a new indication is deemed to be a "New drug" and must undergo a series of safety and efficacy studies both in animals and humans before its use in general public.

But, letrozole was approved on the basis of the phase-III trials conducted by Sun Pharmaceuticals on a mere 55 patients, that too conducted by private practitioners in personal clinics while such studies should have been conducted on larger number of patients by independent, experienced investigators in large, research hospitals attached to medical college to avoid any bias results.

If the drug is intended for use in young women of child bearing age, reproductive studies including fertility studies, teratogenicity studies and perinatal studies must be performed in two female animals such as mouse, dog or rabbit. The drug must also undergo phase I clinical trial in about 10 healthy volunteers (pre-menopausal women over 18 years of age) to determine the maximum tolerated dose and document preliminary side effects.
Exploratory phase-II studies to determine the therapeutic use, dose and safety of the drug are to be conducted in 10-12 patients in each of 3 to 4 research hospitals. But, these studies were not done, well-known health expert and Editor of the medical journal MIMS, Dr CM Gulhati said. He regretted that none of the above studies were conducted by Novartis or any other company anywhere in the world since the drug was never intended to be used in women of childbearing age.