The majority leader of the state Senate soon will become executive director of a national organization of legislators fighting high prices for prescription drugs.

Sen. Sharon Treat, D-Farmingdale, will become leader of the National Legislative Association on Prescription Drug Pricing in September.

Treat assumes the directorship from Vermont Sen. Cheryl Rivers, who is leaving to serve as that state’s lieutenant governor.

The organization’s headquarters in Vermont will move to Hallowell when Treat starts.

The announcement of Treat’s appointment was made Tuesday by her State House colleague, Rep. David Lemoine, D-Old Orchard Beach, who serves as chairman of the organization’s board.

Calling Treat “the most qualified person in the United States” to head the organization, Lemoine said, “NLA-Rx couldn’t find a better, more informed executive director than Sharon Treat, who has led the crusade in Maine for improving access to prescription drugs.”

Treat, a 14-year veteran of the Maine Legislature, is prevented by term limits from running another campaign when her term is finished at the end of November. She is widely credited for her support of health care reforms, especially initiatives affecting the cost of prescription drugs.

Treat provided key support for the low-cost drug program Maine Rx Plus, which has become a model for similar initiatives in other states. Treat also spearheaded legislation that requires pharmacy benefit managers – companies that handle drug benefits for major insurance companies and employers – to disclose their contractual agreements with drug manufacturers. Most recently, she sponsored a bill to require drug makers to provide manufacturing and marketing costs to the state.

She has served on the NLA-Rx board since 2002.

Treat said in an announcement that states must take the lead in fighting high drug prices “in the absence of meaningful federal action. I look forward to continuing this work with forward-looking state legislators to expand access to life-enhancing prescription drugs at affordable prices,” she said.

NLA-Rx was established in 2000. Membership includes representatives from Maine, Vermont, New Hampshire, Connecticut, Massachusetts, Rhode Island, New York, Pennsylvania, the District of Columbia and Hawaii. Legislators who belong to the bipartisan organization meet four times a year to learn about the drug industry and to develop strategies for keeping medications affordable.