The chief executive officer of Myriad Genetics Inc has said that the lab tests to pin point the tumour drug. The shares of the French drug maker fell, Sanofi on Friday due to a mishap. The lead drug in its research program failed in the last few stages of clinical research.

Sanofi has quoted in his statement that Iniparib, or BSI-201 an experimental drug was used to treat the advanced breast cancer has failed in its last stages of the clinical tests and has failed to show any form of life extension and cure.

This cancer drug was expected to bring about $800 million in revenue by the end of 2015. The brokers now think that the revenues will suffer a massive blow for this company in future.

"We cannot view this as anything other than a major setback as we had expected BSI-201 to lead a revival in Sanofi-Aventis's formerly No. 2-ranked cancer franchise," Deutsche Bank analyst Mark Clark said, though he kept his "buy" rating on the stock.

This has been a fresh blow for Sanofi. Earlier this month teo patients suffered liver failure after taking Multaq Heart Drug manufactured by this company.

Sanofy is reported to be trying to buy the U. S. biotech group Genzyme for $18.5 billion. It also aims to target the patient losses of this year.