A “rigged payment scheme” among drug plans, insurers and pharmaceutical companies blocks access to cheaper versions of some of the most costly drugs in the U.S., the head of the Food and Drug Administration said Wednesday.

FDA Commissioner Scott Gottlieb aimed particular criticism at giant pharmacy benefit managers that contract with health plans to administer coverage of drugs, saying the industry’s contracting tactics have stymied cheaper copies of expensive biotechnology drugs. Known as PBMs, the companies include Express Scripts Holding, CVS Health and UnitedHealth Group’s OptumRx unit.

“Consolidated firms — the PBMs, the distributors, and the drug stores; team up with payors,” Gottlieb said in prepared remarks at a major conference of health insurers in Washington. “They use their individual market power to effectively split monopoly rents with large manufacturers and other intermediaries; rather than passing on the saving garnered from competition to patients and employers.”

The speech is some of the Trump administration’s broadest criticism yet of the health care industry. While the FDA has little or no power over PBMs, Gottlieb’s remarks make clear that administration health officials place the blame for high drug costs not just on biotechnology and pharmaceutical companies, but also on other parts of the complex medical supply chain.

Gottlieb said the arrangements between PBMs, drugmakers, insurers and distributors threaten the market for what are known as biosimilars, cheaper versions of complex biotechnology drugs. Unlike pills, biotechnology drugs are made from living cells, and have advanced the treatment of many diseases. They’ve come with record prices.

Biosimilars were meant to be a less costly alternative to the products, and Gottlieb called them necessary for a competitive market that works for patients. A 2010 law created a way for the FDA to approve the drugs and help doctors and patients decide how to use them. Their uptake has been stymied by what Gottlieb said were opaque contracts that favor the older, more costly drugs.