ABSTRACT
Background: SARS-CoV-2 infection may be a threat for those undergoing active anti-cancer therapy. We aim to study adverse events, efficacy, and immune response in Covid-19 vaccinated patients focusing on possibly interfering therapy. Methods: CoVigi is a prospective open-label multicentric phase 4 clinical study (EudraCT 2021-000566-14) enrolling patients on anti-cancer treatment. Vaccines from Pfizer-BioNTech, AstraZeneca, Johnson&Johnson, or Moderna are considered. Data on vaccination side effects, the onset and course of Covid-19, and quantitative analysis of anti-S and anti-N SARS-CoV-2 antibodies (Roche) and SARS-CoV-2 specific cellular response evaluated by IFN-gamma-release assay (Qiagen) and CD69 expression are recorded as follows: at the baseline (prior to the vaccination), prior to the 2nd dose, 4–8 weeks, 3, 6 and 12 months after the first dose. Results: The trial was initiated on March 22th. As of May 4th, 152 solid cancer and 103 hematooncology patients were enrolled. From preliminary baseline data, 22% of solid cancer and 29% of hematooncology patients had detectable levels of anti-S antibodies with a median of 106 U/ml (range 1.4–3666) and 84 U/ml (range 0.75–2528), respectively (p = 0.888). Surprisingly, only 44% solid cancer and 53% of hematooncology patients with detectable antibodies prior to the vaccination referred on covid-19 in medical history. In the Ab-positive cohort, the IFN-gamma level upon both CD4 and CD8 stimulation was 0.04 pg/ml (IQR 0.02–0.13), the CD69 expression on NKT-like cells increased to 10.9% (IQR 6.6–17.3), whereas in the Ab-negative cohort was 0.00 pg/ml (IQR 0.00–0.01 and to 7.5% (IQR 4.0–10.1), respectively (p < 0.001 and p = 0.079). Conclusions: Substantial number of cancer patients experienced SARS-CoV-2 infection during active anti-cancer treatment prior to vaccination, often with asymptomatic course. In SARS-CoV-2-immunized patients, we observed SARS-CoV-2 positive cellular response. The preliminary results with dynamics of immune response with 3-month follow-up will be presented at the conference. Acknowledgment: CZECRIN LM2018128, Roche Diagnostics, MMCI00209805, MHCZ/DRO (FNBr, 65269705). Clinical trial identification: EudraCT 2021-000566-14. Legal entity responsible for the study: Masaryk University. Funding: CZECRIN. Disclosure: All authors have declared no conflicts of interest.