MARY LOUISE KELLY, HOST:

A federal judge in Texas is expected to rule in a case challenging the Food and Drug Administration's approval of an abortion pill some 20 years ago. If the judge sides with the anti-abortion group that brought the case - and he is expected to - it could have ripple effects on drug approvals as we know them. Well, NPR pharmaceuticals correspondent Sydney Lupkin is here in the studio to explain. Welcome, Sidney.

SYDNEY LUPKIN, BYLINE: Hi.

KELLY: OK. I want to start with the stakes because I'm trying to understand how this one case about just one pill has the potential to change how the FDA OKs medicines.

LUPKIN: The case is over mifepristone, which is used in first-trimester medication abortions in combination with another pill called misoprostol. The anti-abortion group that's suing, Alliance Defending Freedom, is basically saying that the FDA never had the authority to approve mifepristone in the first place. They say the way the agency approved it required them to call pregnancy an illness, which it is not. I spoke to Harvard Medical School's Ameet Sarpatwari.

AMEET SARPATWARI: But the preamble to this rule makes it clear that when FDA meant was conditions or diseases that can be serious for certain populations in some or all of their phases, which would include pregnancy.

LUPKIN: The lawsuit is also questioning whether the FDA correctly considered safety and effectiveness when it granted this approval, which is interesting for a drug that's been on the market for 20 years.

KELLY: Indeed.

LUPKIN: Vice President Kamala Harris talked about that this morning.

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VICE PRESIDENT KAMALA HARRIS: Most Americans could look in their medicine cabinet, where they will find medication prescribed by a doctor that they use on a daily basis and have available to them because the FDA engaged in a process of determining the efficacy and safety of that medication. Mifepristone is no exception to that process.

LUPKIN: She said those who attack that process should look in their medicine cabinets and be prepared for the repercussions of those decisions.

KELLY: OK. Sydney, practically speaking, what would change if the judge, as expected, does rule in favor of the anti-abortion group?

LUPKIN: Well, part of what could change is that women could only get one kind of medication abortion using one pill, the second one, which is less effective and more painful. And it could also set this precedent for court interference in FDA expert decision-making. So for the last 60-odd years, the FDA has been the global leader in approving drugs based on rigorous safety and effectiveness standards, and now a court could, like, undo that. So that could have a chilling effect on the FDA, which broadly doesn't have the resources to get sued a lot. It's expensive to the taxpayer. It limits other things the agency can do. So the FDA might be more cautious about approvals. Here's Sarpatwari again.

SARPATWARI: If a court is willing to say in the face of this evidence that this drug is not safe or is ineffective, then what else might it potentially say is unsafe or ineffective?

LUPKIN: And in a politically charged climate, that could mean drugs for future hormone therapies for gender-affirming care, PrEP for HIV prevention. So those drug companies might not want to invest in the development to begin with if that, you know, risk is that the court could just overturn the approval anyway. And the FDA, again, not wanting to be sued, might look backwards in time and do withdraws.

KELLY: In a case where the stakes are so high, as you've just filled in, do we expect that however the judge rules, there will be an appeal?

LUPKIN: So, yes, I'm told this will likely go to an appeals court and make it all the way up to the Supreme Court according to Robin Feldman at UC Law SF. It seems like this was basically written for the Supreme Court. So in the meantime, another case has been filed today, actually, by several states attorneys general challenging the FDA's restrictions on Mifepristone that have been in place since its approval. And they're arguing the drug is safe and effective and those restrictions aren't really necessary. I'm told they could file an injunction against the FDA to prevent it from removing the drug from the market. So you really have these, like, dueling lawsuits, one by conservatives and one by Democrat-led states.

KELLY: NPR pharmaceuticals correspondent Sydney Lupkin. Thank you.

LUPKIN: Thank you. Transcript provided by NPR, Copyright NPR.