Monoclonal antibody bamlanivimab appeared to work for end-stage renal disease (ESRD) patients in early data from dialysis providers, but there are plenty of questions that remain.

The first 40 dialysis patients who got the antibody treatment at U.S. Renal Care clinics had a 7-day hospitalization rate of 15% compared with 57% among a randomly sampled comparator group of 49 coronavirus-infected dialysis patients matched for age, gender, diabetes status, and race.

The 30-day hospitalization rate was 39% versus 65% for those patients treated from when the dialysis network first started administering the drug January 5 through the end of February.

That represents almost the totality of their experience with the drug, said Mary Dittrich, MD, chief medical officer of U.S. Renal Care, who reported their data at an American Society of Nephrology webinar earlier in March.

With falling case counts nationwide, only another five patients have been dosed since, she told MedPage Today. “A tradeoff that I’m very willing to make is that our infections have gone down, so our administrations have gone down.”

Fresenius Medical Care North America and DaVita Kidney Care have also been tracking their numbers and results, with their larger patient populations.

Across DaVita’s more than 220 infusions, no adverse events were reported with the infusion or in the 1-hour observation period after it, George Aronoff, MD, vice president in DaVita’s Clinical Affairs Office, told MedPage Today.

“Only about 9% of our patients who have received the infusion have required hospitalization within 21 days following infusion,” he noted.

Fresenius reported similar results: “Since offering this antibody treatment in our dialysis centers in early January, our preliminary data suggests that less than 10% of patients who received the therapy were hospitalized within the first 28 days after treatment,” said its chief medical officer, Jeffrey Hymes, MD.

Altogether, it appears that bamlanivimab — developed and sold by Eli Lilly — safely reduced progression of disease in the ESRD population, Dittrich said. “It’s small numbers and it’s early, but given the paucity of any data in our population…that’s the data we’re excited about.”

Few, if any, ESRD patients were included in those pivotal clinical trials, so some data is better than none, she noted.

“It has been gut-wrenching to be helpless in this pandemic,” Dittrich said. “To have any option both in terms of vaccines and these monoclonal antibodies is inspiring.”

However, there are some big cautions with this observational data. So much so that her group decided not to publish, she said.

Monoclonal antibodies have to be given as outpatient treatment after a positive for COVID-19, but there are logistical issues, Dittrich noted.

A large portion of dialysis patients are admitted soon after COVID-19 diagnosis, typically within 5 days. In U.S. Renal’s data, the average time to bamlanivimab administration after diagnosis was 4 days.

“There is inherent bias,” she warned. “It’s very possible that we selected for a certain group of patients to get bamlanivimab — those with milder disease, those who were going to stay outpatient for 4 days.”

Hymes noted that the early Fresenius data will also require further analysis to correct for possible baseline differences in the characteristics of patients who did and didn’t get the antibody.

Another issue is that the data only included bamlanivimab monotherapy, whereas distribution of that drug has stopped due to reduced efficacy against SARS-CoV-2 variants such as those identified from California and New York. Instead, the combination of bamlanivimab and etesevimab (also from Eli Lilly), and a two-antibody cocktail developed by Regeneron Pharmaceuticals, are the ones being distributed.

“I do worry about how the variants rising in prevalence is going to affect the efficacy of this therapy, and that’s one thing we’ll be watching closely,” Dittrich said. “I don’t know that we have the ability to genomically sequence all our patients, but we want baseline efficacy data out there, knowing that the variants may change that data.”

Fresenius continues to advocate use of monoclonal antibodies for appropriate patients, Hymes noted, with recently updated clinical guidelines to emphasize the availability of the combination antibody and the discontinuation of bamlanivimab monotherapy.

Monoclonal antibodies are still relevant even as vaccination will be rolling out to ESRD patients through dialysis clinics nationwide in the next few weeks, Dittrich said.

“With the variants and the country opening back up, we worry that numbers are going to go back up,” she said. “Especially if these variants cause more severe disease, which there is some suggestion they do, this will be even more relevant.”

Last Updated March 30, 2021