US FDA Finds Carcinogen in Some Diabetes Drugs by Merck

The US Food and Drug Administration (FDA), said certain samples of sitagliptin, a compound in diabetes drugs Janumet and Januvia by Merck, were contaminated with a possible carcinogen.

The US FDA said it will temporarily allow Merck to market and distribute drugs with sitagliptin, which contains a higher-than-normal acceptable amount of the impurity known as Nitroso-STG-19, which is also called NTTP, in order to avoid a shortage of the drugs.

Merck said it has notified the authorities that it has detected that some batches of the drugs contain the impurities, and has also implemented additional quality controls to ensure its drugs will possibly meet the interim acceptable limits.

Merck said they remain confident in the safety, quality, and efficacy of their medicines or drugs containing sitagliptin. 

The shares of Merck have dropped sharply before recovering to close up more than 1 percent at 89.53 dollars. The sales of Januvia and a related combination of medicine called as Janumet totalling 1.23 billion dollars in the second quarter of 2022.

US FDA scientists have evaluated the risk of exposure to NTTP at interim acceptable levels of intake of around 246.7 nanograms per day, and have determined that it presents a minimum additional cancer risk when compared to a lifetime of exposure to NTTP at the daily level of 37 nanograms.