Baxfendy Approval Shows What FDA Counts as a Novel Drug

AstraZeneca said on May 18 that the Food and Drug Administration had approved Baxfendy (baxdrostat), an aldosterone synthase inhibitor, for the treatment of hypertension in combination with other antihypertensive medications in adults whose blood pressure is not adequately controlled. FDA's list of novel drug approvals for 2026 records the approval on May 15, the 15th entry of the year.

The company's announcement said the approval was based on the BaxHTN Phase III trial, published in the New England Journal of Medicine. According to AstraZeneca, the 2 mg dose lowered mean seated systolic blood pressure at week 12 by 15.7 mmHg from baseline, or 9.8 mmHg after adjusting for placebo; the 1 mg dose lowered it by 14.5 mmHg, or 8.7 mmHg placebo-adjusted. The company said the drug can cause hyperkalemia and hyponatremia and that potassium and sodium should be assessed before and during treatment. It described Baxfendy as "a first-in-class aldosterone synthase inhibitor (ASI)."

Two labels are at work in that announcement, and they come from different places. One is FDA's own category of novel drugs; the other, first-in-class, describes how a drug works.

What makes a drug novel

FDA's Novel Drug Approvals at FDA page says "Novel" drugs are new drugs never before approved or marketed in the U.S. The Center for Drug Evaluation and Research also approves many products each year that FDA describes as the same as, or related to, previously approved products. Those are not on the novel list.

The novel list combines two kinds of applications. New molecular entities, or NMEs, are approved under new drug applications; new therapeutic biologics are approved under biologics license applications. The list leaves out vaccines, blood products, cell and gene therapies and other products approved by FDA's biologics center, CBER, so it is not a count of every new medicine.

The NME label has its own fine print. FDA says many NMEs contain active moieties it has never approved, but some are classed as NMEs for administrative purposes even though their active moieties are closely related to approved ones. The agency says classing a drug as an NME for review purposes "is distinct from" deciding whether it is a new chemical entity under the Federal Food, Drug, and Cosmetic Act.

What first-in-class adds

Being novel means the molecule is new to the US market. Being first-in-class is about mechanism. In its annual report on 2025 approvals, published in January 2026, CDER identified 20 of the year's 46 novel drugs, or 43%, as first-in-class and said "These drugs have mechanisms of action different from those of existing therapies." The same report said 34 of the 46 were NMEs and 12 were biologics, that half received orphan drug designation and that 33 used at least one expedited program: fast track, breakthrough therapy designation, priority review or accelerated approval.

CDER published those first-in-class identifications for 2025 in its year-end report. A company's description of its own product as first-in-class, as in AstraZeneca's release, is the company's claim, not an FDA designation.

Where the numbers come from

CDER says it has averaged roughly 47 novel approvals a year from 2016 through 2025, with 46 in 2025. Its 2025 report also said 39 of the 46 novel drugs were approved on the first review cycle, and 32 were approved in the US before any other country.