FDA's Hahn to Topol: Decisions Will Be Made on Science Alone

FDA's Hahn to Topol: Decisions Will Be Made Based on Science Alone

; Stephen M. Hahn, MD

Disclosures

October 09, 2020

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This transcript has been edited for clarity.

Eric J. Topol, MD: Hello. I'm Eric Topol, editor-in-chief of Medscape, and I have the privilege today to interview Dr Stephen Hahn, the commissioner of the FDA. So, Stephen, welcome. It's great to have you with us.

Stephen M. Hahn, MD: Well, Eric, it's great to be here. I appreciate the invitation. And I'm looking forward to our conversation. These are really important topics for the country.

Topol: No question. Just as a way of background. Dr Hahn came on as commissioner of the FDA in December. I don't think he knew exactly what he was getting into. He has an amazing background. Undergraduate at Rice and Temple for medical school. We actually shared some history at the University of California, San Francisco, where he did his medical residency. He was also trained at NIH in oncology. He went on to have an illustrious career. He was at the University of Pennsylvania where he was chair of the radiation oncology department, and from there he moved to the University of Texas MD Anderson Cancer Center, where he was the chief medical executive. So, quite a pedigree background, Steve, that got you ready for this tough mission ahead.

Hahn: Thank you.

Topol: It's remarkable how we came together. We didn't know each other until I sent you a very tough letter back on August 31 about the convalescent plasma decision. Little did I know that it would be a blessing because it would bring us together. Dr Hahn was kind enough to get in touch with me and we've actually become friends. I've developed immense trust in him and his efforts. We're going to get into that with respect to vaccines and monoclonal antibodies today.

Let me start off, Steve, with the acronym of the day: EUA. Can you tell us what that is and how it's become kind of center stage in the midst of the pandemic?

Hahn: Eric, first of all, when you sent the letter — I have to tell you, I learned this in medicine: You run toward friction and you talk to people about things. I very much appreciated your communicating with me. And I feel the same way. So thank you.

It's hard to believe that EUA, or emergency use authorization, has become part of the lexicon of the United States, maybe the world. After the 9/11 terrorist attacks, we received this authority from Congress to issue EUAs to allow for medical products to get into the hands of providers and patients before the full set of data were available that we would normally use during our regular approval process.

There are two important points of EUA. One is that, from a treatment or a therapeutic point of view, the standard is "may be effective." There has to be evidence that something may be effective. We have to have data behind that.

The other one is the assessment of the risk-benefit ratio. And that's where the safety comes in. You can imagine a situation where you have an incredibly life-threatening infectious disease — COVID-19 and Ebola would be examples of that — where the risks are high. Eric, just like doctors would make a decision in a situation where the risk for death is high, you might accept more risk on the therapeutic side from a safety point of view.

And that, of course, plays directly into the issue of therapeutics vs vaccines, because therapeutics are given to people who are sick, maybe even in life-threatening situations. Vaccines are given to people who are, in general, healthy but may be at risk for life-threatening complications. All of that has to play into our decision-making, and that's what the experts at FDA are really good at.

Topol: Well, that's really being put to the test now with the vaccines. There are multiple phase 3 programs underway. We were fortunate that we pushed the manufacturers to release their protocols because I don't think that was their initial intention, but they did. First it was Moderna and Pfizer, then AstraZeneca and Johnson & Johnson, and finally Novavax.

These protocols have a lot of homology. Most of them have approximately 150-160 endpoints of infections. These are some of the largest trials that have ever been conducted, from 30,000 enrollees up to 60,000 for Johnson & Johnson's. What's interesting here is that you have a relatively small number of events that could lead to an interim analysis — 32, for example, in Pfizer. And you're extrapolating that to tens of millions, even hundreds of millions, of people.

That makes for a strain. I mean, it's hard to know from a trial like this, when you're evaluating it for EUA, that you've nailed it, that it's truly efficacious and safe. Can you comment about this? This is a momentous time for clinical trials when, even though they're large, the number of events that will be influential in making critical decisions is small.

Hahn: Eric, this is, as you point out, the central issue. It's why we issued guidance on June 30th about our expectations. One of the reasons that these trials are the size they are is because we established a floor of 50% efficacy. Now, you and I and the rest of the country want to have a hugely efficacious vaccine and certainly a safe one. But these trials were powered and designed based upon that — detecting a 50% difference.

That being said, you're right. A data and safety monitoring board (DSMB) could look at prespecified time points and see if the boundaries of that efficacy have been reached. What we've been very clear about with the manufacturers and sponsors is that the FDA needs to see clear and compelling evidence around both safety and efficacy. In the absence of that, it's going to be very difficult for us to consider authorization of a vaccine. Of course, the proof is in what the data show, and we don't know what the data will show. But I think we've been very clear about that and we've had conversations with the sponsors, which I can't reveal here because it's confidential commercial information about what we would expect to see, because I think we need to be very, very clear about what "clear and compelling" evidence is. And we need to make sure that it is something that is durable, that it's not just seen in an initial analysis and then goes away later. We're working on that without revealing the details of the conversations. It's top of mind for us, Eric.

Topol: What's interesting is that there's kind of two compartments. There's Pfizer, which is working on its own trial, and there's Operation Warp Speed (OWS). I'm not sure that's the best name but it's "Warp Speed." Do OWS and the FDA have any interactions, and, for the medical community, what is this OWS?

Hahn: This is really, really important. OWS is run jointly by the Department of Health and Human Services (HHS) and the Department of Defense. It is a program to help expedite diagnostics, therapeutics, and, of course, vaccines, and to provide government money. This is the people's money, their tax dollars, supporting the expediting of medical product development, including vaccines, which means manufacturing at risk before there is an authorization of approval, just for one example, and creating a common platform for potentially testing therapeutics and vaccines.

We have drawn from the beginning a very bright line between FDA activities and OWS. We provide technical assistance. But neither I, nor anyone at FDA, is involved in any decision-making, because think about it, Eric: Let's say there's a commercial company that's developing a product. If FDA were involved in the commercial decisions of that company, how could we possibly be an independent regulator? So we've made it clear that we're not going to — and we haven't — participate in any decisions. We'll provide them with technical advice just like we would for any other sponsor of a medical product. Now, OWS's job is to work with various sponsors and manufacturers to facilitate the development of vaccines and other medical products. That's actually happening. But we're only in the position of providing technical assistance to them, which I think is the appropriate place for us to be.

Topol: Pfizer is running its trial on its own and has its own DSMB. There are four interim analyses, which is more than the other vaccine protocols. And for each interim analysis there are stopping rules and they could apply for an EUA at any time. This is why we got concerned; they could come in with a small number of events and they could kind of bypass the FDA and go right to HHS, which I guess has authority over EUAs, such that they could essentially bypass the review process. Is that right by legal authority?

Hahn: That's a really good question. I don't think people know this, but the secretary of HHS by statute in the Food, Drug, and Cosmetic Act delegates his authority to the commissioner of FDA. And I'll go through that in just a minute.

What I've done, and what previous commissioners have done, is delegate that authority to the center directors — in this case, the Center for Biologics Evaluation and Research (CBER), and in terms of monoclonals, it's the Center for Drug Evaluation and Research (CDER). So under my watch those decisions will be made by scientists within the centers.

Our expectation is that when an application comes to us — and again, that's the decision a sponsor makes based upon their determination that data are mature — we're going to work with them; we're going to be flexible. But we're also going to be insistent about our criteria. And we've communicated those criteria both in our guidance and also in letters to the manufacturers. Once a sponsor submits an application to us, we're going to look at those data, but we're also going to open this up to a vaccine advisory committee. That will allow us to have independent experts comment on this. So there are a lot of safeguards in place, both for our scientists and also for this external public-facing advisory committee, to assess those data. Everybody's aware of that. I think when an application comes in, we're confident that it's going to be ready to be assessed. But either way, we promise that the process will be the same for every application.

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