Updated

Massachusetts' attorney general is studying whether the prices of Gilead Sciences Inc's blockbuster treatments for hepatitis C violate state law, according to a letter the prosecutor sent to the California drugmaker.

The letter from Attorney General Maura Healey to Gilead Chief Executive Officer John Martin, dated January 22, asked the biotechnology company to reconsider its pricing for Sovaldi and Harvoni, Gilead's treatments with list prices of $84,000 and $94,500, respectively, per course of treatment.

"My office is considering whether Gilead's pricing strategy with respect to Sovaldi and Harvoni may constitute an unfair trade practice in violation of Massachusetts law," Healey said in the letter, a copy of which was supplied by email to Reuters.

Gilead has been harshly criticized by insurers, politicians and patient groups for prices of the two treatments, which can cure well over 90 percent of patients with the liver disease. The Foster City, California-based company has defended its prices, saying the drugs greatly reduce long-term costs to the healthcare system by preventing liver cancer and the need for liver transplants.

Gilead did not immediately respond to an email seeking comment.

(Reporting by Ransdell Pierson; Additional reporting by Bill Berkrot; Editing by Jonathan Oatis)