REPUBLICANS ARE signaling that they will pursue an ambitious conservative agenda when they take the reins of government next year. But before that happens, the current Congress will convene in its lame-duck session, valuable legislative time that Senate Majority Leader Mitch McConnell (R-Ky.) said this week he hopes to put to good use.

The session may be consumed by arguments over federal budgeting. But if there is time for anything else, Mr. McConnell may push the 21st Century Cures Act, a bipartisan effort that has taken years to get close to passing. Congress should nudge it across the finish line — taking care to repair a few problems along the way.

The act, a version of which passed in the House last year, proposes a one-time, multibillion-dollar increase in funding for the National Institutes of Health. The money could provide a sharp boost to the Obama administration’s cancer initiative, or to research into precision medicine, which tailors treatments to people’s genomes. Rapid progress in both is possible and could save many lives; new cancer drugs have emerged targeting specific mutations in tumor cells, and they have shown encouraging initial results in treating even some of the most complex cancers. The new funding could also go into competitive grants for scientists with particularly innovative projects that are nevertheless underfunded. Given that so many lifesaving pharmaceuticals have their origins in government-sponsored scientific research, the funding boost would be a good investment.

The new money alone, however, would struggle to attract strong bipartisan backing. So lawmakers linked it to various reforms of the Food and Drug Administration’s approval process, arguing that the agency has been hamstrung in getting new drugs to market. One reform on the table would adjust hiring standards at the FDA, which is perpetually short-staffed. The agency has improved on the time it takes to approve new medications, but a more flexible hiring policy could help further. There are also worthwhile provisions that would give gravely sick patients with few options easier access to experimental medication.

Critics have raised some valid concerns. For example, lawmakers should ensure that a proposed adjustment to rules on the approval and use of new antibiotics does not have the unintended side effect of encouraging antibiotic overuse and resistance — the very problem the provision is supposed to combat.

The bill’s backers insist that the FDA’s bottom-line legal mandate would continue to ensure that drugs were safe and effective, even as the agency was granted more flexibility in meeting that standard. This means, then, that it would be up to the FDA to use its new powers wisely.

Despite the caveats, though, the act is worth supporting. If the lame-duck Senate can pass its version and merge it with the House’s, addressing some of the concerns in the process, it would be a valuable use of Congress’s time.