Texas legislators are entitled to details about how pharmaceutical giant Pfizer priced drugs offered through the state's expansive Medicaid program, according to a judge's ruling in a year-old case.

The case hits at the core of a drug cost debate that has been frustrating policymakers nationwide.

The Texas Health and Human Services Commission last year provided two state lawmakers, who were trying to draft budget and legislative proposals, details about Pfizer’s negotiated drug pricing rates in the Texas Medicaid program, the most expensive health care program administered by the state.

The New York-based drugmaker argued that by providing the data, the commission violated confidentiality agreements and revealed valuable trade secrets. It sued the commission in November.

After reviewing arguments made by both sides during a bench trial held in February, Judge Lee Yeakel of the Western District of Texas concluded that the commission acted appropriately.

“In Pfizer's view, legislators are not necessary to carry out the state's Medicaid program,” he wrote in a court document posted Friday.

States, he said, are not freestanding entities capable of acting without their elected, appointed and hired officials. It’s appropriate for legislators to have drug cost data in order to “exercise meaningful oversight” over Medicaid program administration, Yeakel said.

It's a "pretty significant" conclusion, noted Trish Riley, executive director of the National Academy for State Health Policy. "It makes it clear that Legislature does have a vested interest," she said.

And while the judge's decision maintains that access to data remains proprietary, it does give state lawmakers an additional tool. As long as no individual drug or its manufacturer is identified, the state can potentially aggregate information to create a clearer public picture about the program's drug costs. "And there's not been a lot of that," Riley said.

Prescription drug prices have been cited as a main factor driving up health insurance premiums and leading to cost-sharing arrangements that add financial burden for consumers. A report from the Texas comptroller highlights why there’s legislative interest statewide.

During fiscal 2015, nearly 70 percent of the commission’s health care spending supported Medicaid programs, including acute and long-term care services and drugs. That amounted to $17.8 billion.

It was the state's "single most expensive health care program,” one in which even small changes in federal medical assistance percentages can add or subtract millions of dollars from the state’s budget, the report said.

State lawmakers have been seeking methods to offset soaring costs and generate hundreds of millions in savings from Medicaid programs.

State Sen. Charles Schwertner, a practicing orthopedic surgeon, and Jane Nelson, chair of the Senate Finance Committee, asked the commission to provide data on federal and state rebate amounts for drugs listed on the Medicaid Preferred Drug List.

Their separate freedom of information requests were granted by the state agency that Pfizer later sued.

Pfizer said in a statement that it appreciates that the confidentiality of drug pricing and rebate information will remain, but expressed disappointment that the court did not grant "injunctive relief," meaning that lawmakers would be prohibited from requesting the data.

"The company is considering all its legal options," the statement from Pfizer said.

Yeakel called Pfizer’s view on confidentiality provisions “narrow” and said it did not take into account the “complex realities” of operating and funding the state program that provides medical care and prescription drugs to millions of low-income and disabled Texans.

“The court will not construe to carry out so narrowly as to prevent the commission charged with administering the state's Medicaid program from disclosing information that could affect state budgeting to the body which created it,” he wrote.