(Reuters) - Vertex Pharmaceuticals sued the U.S. Department of Health and Human Services on Monday, seeking a court declaration that a fertility support program for patients who are prescribed its gene editing therapy Casgevy does not violate federal anti-kickback laws.

Casgevy is approved for the treatment of two genetic disorders - sickle cell disease and transfusion-dependent beta-thalassemia - in the United States.

The treatment involves patients receiving high doses of chemotherapy, with infertility being a potential risk.

While fertility preservation methods such as freezing eggs and sperm banking are covered under commercial insurance plans, government-supported plans like Medicaid do not offer coverage.

Vertex offers financial support for some Casgevy patients who meet certain eligibility criteria.

The Office of Inspector General, named as one of the defendants in the lawsuit, had previously conveyed to the company that its program could violate anti-kickback laws as it "poses more than a low risk of fraud and abuse to federal health care programs".

The OIG and other defendants in the lawsuit - the HHS, Secretary Xavier Becerra and Inspector General Christi Grimm - did not immediately respond to requests for comment.

Anti-kickback provisions prohibit "quid-pro-quo" transactions, in which remuneration, such as a bribe or kickback, is sought or offered to influence medical decisions.

Vertex said anti-kickback laws do not prohibit support such as the one its program provides.

The program "removes a financial or medical barrier to care and thereby allows patients to receive appropriately prescribed medical treatment," the company said in the court filing.

The lawsuit was filed in the federal court in Washington, D.C.

(Reporting by Jonathan Stempel in New York and Bhanvi Satija in Bengaluru; Editing by Krishna Chandra Eluri)