A New Jersey pharmaceutical company filed a lawsuit against Maine last week, arguing that the state’s new law regulating a discount drug program is illegal and should be voided.

Maine passed a law during the recent legislative session that regulates the federal 340B drug discount program. The 340B program is essentially invisible to patients when purchasing their drugs at the pharmacy, but it allows hospitals and community health centers to get some medications at discount prices.

How extensively the program is used and who can regulate it are at the center of the lawsuit that Novartis Pharmaceuticals Corp. of East Hanover, New Jersey, filed in U.S. District Court in Portland on Aug. 7. Maine Attorney General Aaron Frey is listed as the defendant.

The lawsuit contends that federal law governs the 340B program and states cannot regulate it.

Jeff Austin, vice president of government affairs for the Maine Hospital Association, said in a statement on Wednesday, “We believe Maine’s law is sound and we’re confident it will survive a challenge as these laws have been upheld in Arkansas, Mississippi and Louisiana and many other states.”

Danna Hayes, a spokesperson for the attorney general’s office, declined to comment, saying that the office does not comment on pending litigation.

Proponents of the law, LD 1018, argue that the 340B program, which generates about $300 million in savings for Maine health care providers annually, is used to help safety net programs that serve rural, low-income and underserved populations.

The program mandates that drug companies sell certain outpatient drugs at discounted rates to safety net programs, which reinvest those savings into services and charity care.

The law’s proponents, including the Maine Hospital Association, have argued that pharmaceutical companies and insurers were circumventing the 340B law by placing restrictions on which pharmacies would be permitted to participate in the program. They say that the pharmaceutical industry and pharmacy benefit managers — the industry’s middle men — are exploiting loopholes in order to restrict access and divert funds from the discounts back to the pharmaceutical industry.

Matthew Marston, vice president and chief pharmacy officer at Northern Light Health, said in an April interview that the bill was a choice between “keeping those discounts in Maine” or “increasing the profits of out-of-state drug manufacturers.”

Maine is among about 30 states that have passed regulations to prevent drug companies from restricting which pharmacies can participate.

Lori Dwyer, president and CEO of Penobscot Community Health Care, a clinic in Bangor, told the Press Herald in January that the 340B program is essential to the clinic’s survival. She said drug companies’ use of loopholes in the program to make it harder to access discounted drugs have caused losses in the industry, including $5 million at Penobscot Community Health Care.

“It’s foundational to our programming and to our financial sustainability,” Dwyer said. “The program is one of the really critical components to our stability, and it had been for decades, until recently.”

The 20 community clinics in Maine — called federally qualified health centers — serve about one in six patients in the state by offering free or deeply discounted services and serving populations that may not otherwise be able to access health care.

Novartis is suing other states, including Rhode Island and Oregon, over similar laws regulating the 340B program, according to news reports.

Drug companies contend that hospitals are abusing the system and obtaining discounts when they shouldn’t be.

“The 340B program has recently ballooned from a niche safety-net program affecting a small minority of health care providers into the largest health care program most people have never heard of,” according to the lawsuit.

The growth of the program “has been fueled by the birth of a cottage industry of middlemen (pharmacy benefit managers) that help health care providers exploit the 340B program,” the lawsuit said.

Maine can’t regulate 340B because “federal law creates and governs every detail of this program.” “Federal oversight of the 340B program is exclusive,” according to the lawsuit.