Lilly leads the Covid antibody charge

Recently, Covid-19 vaccines have been grabbing all the headlines. But monoclonal antibodies – which might provide a nearer-term weapon against the pandemic – have been making quiet progress.

Today Lilly reported the first data from a clinical trial of such an antibody. While the results with LY-CoV555 looked promising, they were by no means emphatic, and more data are needed before this approach can be deemed a success. Still, with several candidates already in phase III, a more definitive answer might be available soon.

Blazing a trail

LY-CoV555 is one of these late-stage candidates – it is in a phase III trial, Blaze-2, evaluating its utility in preventing Covid-19 in nursing home residents and staff.

However, it was an earlier-stage trial that yielded interim data today: Blaze-1, in patients with mild-to-moderate Covid. The phase II study tested three doses of LY-CoV555, 700mg, 2,800mg and 7,000mg, versus placebo.

Only the 2,800mg dose met the primary endpoint, change from baseline in viral load at day 11. The lack of a dose response could be troubling, but it should be noted that most patients in the placebo group also showed near-complete viral clearance by day 11. Lilly noted that it had seen better clearance with LY-CoV555 at three days, without giving more details.

Lilly also claimed a benefit on another prespecified endpoint, Covid-19-related hospitalisation or emergency room visit. This occurred in 1.7% of the pooled LY-CoV555 patients, versus 6% in the placebo group, a relative risk reduction of 72%.

However, only a small number of patients were hospitalised – five in the LY-CoV555 and nine in the placebo group – and Lilly did not say whether the difference was statistically significant.

The company said it intends to “quickly” publish the data in a peer-reviewed journal, so this question might soon be answered.

It might also become apparent soon whether Lilly could apply for emergency use authorisation on the back of the Blaze-1 results. This might be a misguided move given the mixed data so far, but the desperation for Covid-19 therapies has seen projects granted EUAs on much flimsier evidence.

Regeneron is coming

Lilly might want to get the jump on Regeneron, its most advanced rival. The latter is testing REGN-COV2 – a cocktail of two antibodies, REGN10933 and REGN10987 – in phase II/III studies in ambulatory and hospitalised Covid-19 patients, as well as in a phase III prevention trial.

Preliminary data are expected “later this summer”, the company has said.

Meanwhile, other big players have recently taken their antibody candidates into the clinic. Glaxosmithkline and Vir Biotechnology dosed the first patient in the phase II/III Comet-Ice trial of VIR-7831 in August; data are expected before the end of the year.

And, also last month, Astrazeneca started a phase I trial of AZD7442, another two-antibody cocktail.

Lilly is also combining LY-CoV555 with another antibody, LY-CoV016, in another part of the Blaze-1 study.

The table below shows that there has been good progress since Evaluate Vantage’s last analysis, at least among the front runners (Anti-Covid antibodies move quickly into the clinic, June 12, 2020).

Hopefully the next set of results will give a clearer picture of the eventual role of these antibodies in the fight against Covid.