NEW YORK (Reuters Health) – Patients with multiple myeloma mount a highly variable antibody response after completing the recommended two-dose COVID-19 vaccination regimen, with some not having any detectable response, according to a new study.

“Patients with zero or low antibodies after both doses/full vaccination should continue wearing masks and social distancing. Their family and social network should be encouraged to get vaccinated, if not already vaccinated,” Dr. Samir Parekh, co-lead author of the study and director of translational research in multiple myeloma at The Tisch Cancer Institute at Mount Sinai in New York City, told Reuters Health by email.

COVID-19 mRNA vaccines are very effective in preventing severe COVID-19 infections or death. But patients with multiple myeloma (MM) are immunocompromised and often on immunosuppressive therapy, and preliminary data suggest their antibody response may be lower and/or delayed compared to healthy people.

To investigate further, Dr. Parekh and colleagues analyzed SARS-CoV-2 spike-binding IgG antibody levels in 320 MM patients who received COVID-19 vaccinations; 69% received the Pfizer-BioNTech vaccine, 27% the Moderna vaccine and 4% unknown.

Of the 260 fully immunized patients, 219 (84.2%) mounted measurable antibody levels which varied by three orders of magnitude (median 149 AU/mL; range, 5 to 7,882 AU/mL), the team reports in Cancer Cell. And the remaining 41 patients (15.8%) had values below the level of detection.

Antibody responses in a control group of 67 healthcare workers selected to best match the MM population were, in comparison, more homogeneous (median 300 AU/mL, range: 21 to 3,335 AU/mL), and none of them had antibody levels below the level of detection.

“Notably, antibody levels in the 38 fully vaccinated MM patients with prior reported COVID-19 infections were 10 times higher than those of MM patients that were naive at the time of vaccination. This difference has been described previously for healthy vaccinated individuals,” the researchers note in their article.

MM patients receiving anti-CD38 antibodies or B-cell maturation antigen (BCMA)-directed therapies were “particularly vulnerable” to having a suboptimal response to COVID-19 vaccination, Dr. Parekh told Reuters Health.

Twenty-four of the 41 (58.5%) “non-responders” were on anti-CD38 therapy at the time of vaccination, 13 (31.7%) were on anti-BCMA bispecific antibody therapy and four (9.8%) had undergone anti-BCMA CAR-T therapy more than three months prior.

“Patients with myeloma should talk to their physicians and obtain COVID-19 antibody testing, especially those actively on chemotherapy,” Dr. Parekh said.

“Patients may benefit from booster doses or passive antibody infusions. This is an area of active research for our team,” Dr. Parekh added.

The study had no commercial funding.

SOURCE: https://bit.ly/3yisuK3 Cancer Cell, online June 28, 2021.

Source: Read Full Article