Robust support for COVID-19 vaccination in cancer patients

The study shows that vaccination with the Moderna mRNA vaccine is "safe in patients receiving immunotherapy, chemotherapy or the combination for a solid tumor. The seroconversion rate is very high after two vaccinations and is not inferior to controls," Dr. Sjoukje Oosting of University Medical Center Groningen, in the Netherlands, reported at the European Society for Medical Oncology (ESMO) 2021 Congress.

The VOICE study explored the potential impact of chemotherapy and immunotherapy on protection afforded by the Moderna two-dose mRNA COVID-109 vaccine in 743 patients from multiple hospitals in the Netherlands.

Participants included patients with and without solid tumors. The cancer patient group was subdivided into those treated with immunotherapy, chemotherapy or chemo-immunotherapy. Inclusion criteria included receipt of immunotherapy within three months and chemotherapy within four weeks before the first vaccination.

There were no new safety signals observed in the cancer patients, Dr. Oosting reported.

At 28 days after the second dose, "adequate" levels of antibodies to the virus in blood were found in 99.6% of cancer-free controls, 83.8% of cancer patients receiving chemotherapy, 93.1% of patients on immunotherapy alone and 88.8% of patients receiving chemo-immunotherapy in combination, she said.

"Although these percentages are high and really encouraging, there is still a significant minority" of cancer patients who had an inadequate response, "up to 16.2% in the chemotherapy group," Dr. Oosting noted.

"Possibly the most important result from the VOICE study is the very clear finding that patients with solid tumors mount a robust serological response very much comparable to that of healthy controls and this is independent of the therapy they receive," said ESMO invited discussant for the trial Dr. Marie von Lilienfeld-Toal of Friedrich Schiller University Jena in Germany.

"The high rates of efficacy of the vaccine observed across the trial population, regardless of the type of anticancer treatment, constitute a strong and reassuring message for patients and their doctors," ESMO press officer Dr. Antonio Passaro of the European Institute of Oncology in Milan, Italy, who was not involved in the study, added in a statement.

Funding for the VOICE study was provided by ZonMw, The Netherlands Organization for Health Research and Development.