Multiple myeloma patients have widely variable responses to the COVID vaccines, according to new research published in Cancer Cell. The research shared by Samir Parekh, MD of Mount Sinai and colleagues showed that myeloma patients in general mount lower IgG antibody responses compared to the general population, however over 81% of myeloma patients did develop antibodies to COVID-19. 

The researchers analyzed 320 multiple myeloma patients who received COVID-19 vaccinations in early 2021 (69.1% had the Pfizer vaccine, 27.2% had the Moderna vaccine and 3.8% were unknown.) Of the patients who were vaccinated, 18.8% of the patients had contracted COVID-19 before their COVID immunizations. 

Myeloma Patient COVID-19 Antibody Results

Out of the 320 patients, 81.3% had IgG antibody levels for COVID at least 10 days after getting their second vaccine dose with a median level of 149 AU/mL. For the fully immunized myeloma patients, 84.2% of them mounted measurable IgG antibody levels (broken into three different levels of magnitude) and 15.8% had values below the level of detection. 

The study used a control group of 67 healthcare workers who had responses that were more consistent and a median level of 300 AU/mL, and no individuals in that group had levels below the level of detection. 

It is important to note that the 38 vaccinated patients with prior COVID-19 infections had antibody levels that were 10 times higher than patients who had never contracted COVID-19, which follows the same pattern as healthy vaccinated individuals with prior COVID-19 infections. The antibody measurements in myeloma patients took longer to develop compared to healthy individuals without co-morbidities. 

Factors of COVID-19 Antibody Development

Myeloma patients who were on treatment had lower IgG antibody levels compared to patients not on myeloma treatment. There were also lower antibody levels for patients on anti-CD38 myeloma treatment and BCMA-targeted therapy, but not other myeloma treatments. Importantly, of the 15.8% (41 patients) who developed no COVID antibodies, 58.5% (24 patients) were on anti-CD38 antibody myeloma therapy at the time of vaccination, 31.7% (13 patients) were on anti-BCMA bispecific therapy and 9.8% (4 patients) had undergone BCMA CAR T therapy more than three months prior. 

Other significant factors for not developing COVID antibodies included:

• More than 3 prior lines of myeloma treatment
• Receiving active myeloma treatment
• Grade 3 lymphopenia at the time of vaccination
• Time since a myeloma diagnosis
• Response status
• Vaccine type

Myeloma Patients Developing COVID Following COVID Vaccination

The study authors noted that they observed 10 cases of COVID-19 in myeloma patients after one dose of the vaccine (7 patients) or both doses of the vaccine (3 patients). Six of the 10 patients received outpatient treatment but four of the patients needed hospitalization due to severe COVID-19 and one patient died after prolonged intubation. None of the other myeloma patients developed symptoms after vaccination. 

The authors conclude that two vaccine doses are necessary to better protect myeloma patients and approximately 16% of patients will not develop IgG antibodies even after COVID vaccination. The authors suggest that additional studies will determine how persistent the vaccinations are for myeloma patients after the second dose. They suggest that further use of preventative monoclonal antibodies for COVID may be helpful for myeloma patients to avoid greater risk and that booster shots may be needed.