WASHINGTON (AP) — The House will try again next week to pass a Republican bill to help fatally ill people try unproven treatments — and supporters seem likely to prevail.

The House rejected the measure Tuesday, even though the vote was 259-140 for the legislation. It lost because GOP leaders used a procedure normally reserved for uncontroversial bills that requires a two-thirds majority for passage. Tuesday's vote fell just short of that margin.

Under the measure, the Food and Drug Administration would no longer have to sign off if a doctor and a drug manufacturer agree to let a patient try a pharmaceutical that's not yet been approved by the federal agency.

Democrats say the measure is unnecessary because under an existing program, the FDA already approves 99 percent of such requests.