Since I did a monoclonal antibody update in the last post, here’s one on the vaccine front, where there is a lot of news – and where there are a lot of issues coming up similar to the ones with the antibodies as well. The last vaccine update post was here.
What we’re seeing now is the plan for entering large-scale human trials. The Wall Street Journal‘s Peter Loftus broke the news of the overall plan in the US: Moderna’s candidate was said to be going into Phase III in July, followed by the Oxford/AstraZeneca effort in September, with Johnson & Johnson’s vaccine to follow. But J&J now says that they’re moving up the timetable and negotiating with the NIAID for Phase III trials before then. Moderna has selected 100 micrograms as the Phase III dose, which is what was expected based on their earlier results. (Update: a preprint from Moderna and their collaborators has just appeared, detailing the early work and mouse studies on their vaccine candidate). Meanwhile, AZ says that they will be scaling up the manufacturing of the Oxford vaccine during the trials themselves, on a risk basis, and it would not surprise me at all to see other companies doing something similar. They’ll basically have to – if one or more of these vaccines reads out well in Phase III, you’d want to get to dosing people as quickly as possible.
Note that Pfizer (and their partner BioNTech) are not part of this government-funded initiative – they’re going it alone, and (as mentioned before) seem to be taking the largest number of potential vaccine candidates into human trials. It’s definitely an effort to be taken seriously. And then you have the Sanofi/GSK work, which has been less in the news, but involves two of the most experienced vaccine companies in the world. So don’t ignore them, either. Merck is in the same category. Another company to keep in mind is Novavax, last mentioned here. They have now announced (no formal report yet) what appear to be very high antibody titers in primate dosing with their vaccine candidate, which they attribute to their proprietary adjuvant. As noted in that article, it’s impossible to directly compare these numbers with those reported in the other primate studies, but these results are certainly of interest. They’re expanding their manufacturing capacity as well.
Things are also moving very quickly in China, although with less information overall. Bloomberg reported that two of the vaccine candidates are being offered to employees of state-run companies who are traveling outside China for work, with data to be collected on that cohort, naturally. The Chinese Phase III trials are something of a mystery, at least to me, because it doesn’t appear (at least from the official figures) that there are any particularly good opportunities for testing them inside China at this point. So it will be interesting to see how those are going to be run, and where.
Unfortunately, that doesn’t look like a problem we’re going to have here in the US. In several states, cases are rising again, and in some others they certainly don’t seem to be falling. As many had predicted, we seem to be in for months of patchy brush-fire types outbreaks in various regions of the country. What will be tricky is coordinating the locations of all those clinical trials – ideally, you’d want them in the areas where the coronavirus is spreading most vigorously, but can those be identified in time to get a trial off the ground? Throw in the “second wave” possibility in the fall for even more uncertainty. In the end, the data will be collected from centers all over the country, and some of them will just have a better signal/noise than the others. I do not envy the folks coordinating all this, nor the ones who will be working up the data under time pressure.
There are other factors – former FDA head Scott Gottlieb noted on his Twitter account today that it doesn’t seem like the NIH/NIAID coordinated trials will be sharing control groups (which in theory is something that could speed things up). In practice, that savings might have been difficult to realize, but it’s interesting that it seems to have been ruled out from the start. It’s also unclear how data on the the US-company vaccine candidates will be collected outside the US, or where, or when. I’ve mentioned manufacturing above, and that’s a huge issue that’s going to be coming more into focus. The various vaccines mentioned have (in many cases) quite different processes for production and purification, adding to the complexity. And don’t forget distribution – the next few months will see (had damn well better see) a lot of preparation for what will be a gigantic worldwide rollout, done on a time scale that’s never been tried before.
Finally, there are political considerations. Aren’t there always. The various companies involved all have an incentive to be the first to announce an effective vaccine, of course – that will be a huge publicity event. On top of that, there is surely a desire on the part of the current administration to be able to announce this before the election in November – and let me be clear, this would be true no matter who was in office, or from which party. I will say, though, that the President’s willingness to promote hydroxychloroquine so far during the pandemic does not bode well for his restraint when it comes to potential treatments. The election season will just make that more fraught. And internationally, one can already see some elbow-throwing between the US and China (and potentially between the US and Europe?) on the origin of the first effective vaccine as well. Russia is part of this as well. National pride is at stake, which also can lead to some otherwise-irrational behavior.
The next few months, then, are not going to be dull. Politics aside, the organization and execution of all these trials will be a huge and complex effort, as mentioned, and when the numbers start coming out of them we’re going to surely be taken by surprise. That’s what clinical trials do; this won’t be different. I’m expecting sudden reversals, and sudden bursts of hope, despair, and confusion. None of us have ever seen anything like what’s coming, and I hope we never have another opportunity to see anything like it again!