Covid-19 antibody therapies, drugs that mimic the body’s response to infection, have been hailed as a “bridge to a vaccine.” They can’t get us there alone.
Eli Lilly & Co.’s entrant in this category hit a roadblock Monday evening when the National Institutes of Health announced the failure of a key clinical trial testing the medicine in hospitalized patients. The researchers didn’t end enrollment based on harmful side effects — a concern after the trial was halted amid safety concerns earlier in the month — but rather because a look at the data suggested Lilly’s antibody is unlikely to help.
Monday’s news doesn’t mean that the drug or antibodies generally are ineffective. But the fact that one of the most prominent and furthest-along therapy options has limits as a commercial and pandemic-easing prospect isn’t great news in the fight against the virus. Compounding the antibody concerns for Lilly investors, the company’s third-quarter results missed Wall Street estimates; the stock slumped almost 6% on Tuesday morning.
The Lilly and Regeneron antibody treatments still show promise in treating recently diagnosed patients, and trials are continuing to see whether they can serve as a short-term vaccine. Both companies have applied for emergency use authorization from the Food and Drug Administration in milder patients, and it makes sense that they might work better in that setting. Hospitalized patients may have generated antibodies on their own and may have more problems with an out-of-control inflammatory response than the virus that the antibody is targeting.
Regeneron’s treatment is a cocktail of two antibodies, unlike Lilly’s single effort, and could still prove effective in sicker patients. But the failure risk appears high. That’s concerning because patients requiring hospitalization are at the highest risk of bad outcomes or death, putting them in greater need of effective treatments.
While these therapies may be valuable in heading off the virus before it takes hold, that type of treatment isn’t as straightforward as in-hospital use from a commercial or public health standpoint. It is more challenging to show a robust impact or justify high prices in a group of patients who may be more likely to recover independently. It's also still unclear who benefits most from antibodies. Regeneron suggests it could be patients who have trouble producing their own antibodies, while Lilly recommends that people who are older or have other risk factors for severe disease should get them.
Either way, early use presents logistical hurdles. Speedy identification of eligible patients is difficult; Covid testing is unevenly distributed and often slow. The antibodies then have to be promptly delivered and administered with special equipment that isn’t available in an average doctor's office. It’s a big challenge compared with sending supplies to hard-hit hospitals, especially because quantities will be limited at first.
Even in the best of times, the development of medicines is rarely quick or straightforward. We’re seeing that now in the race for Covid-19 treatments and vaccines. However much we may hope for quick remedies, it will take time. It’s best to let the trials continue and focus on what we can control and what can make a difference: wearing masks, washing hands, boosting testing, and limiting potential super-spreading events.
Bloomberg
