Efficacy of SARS-CoV-2 vaccination in cancer patients during treatment: A prospective observational study (ANTICOV trial)

Background: Cancer patients (pts) have higher risk of serious COVID-19 symptoms, morbidity and mortality than general population. SARS-CoV-2 vaccine trials excluded patients with metastatic cancer or undergoing immunosuppressive therapies;therefore, the effectiveness of vaccines are unknown in this population. Hence, there is an urgent need to understand the correlation between cancer type, its treatment and vaccine efficacy. Trial design: Methods: This is a prospective study conducted by the Oncology Unit of Cremona (Cr) Hospital, enrolling pts from Oncology, Hematology, Radiotherapy (RT) and Palliative Care divisions. The trial aims to evaluate effectiveness of mRNA vaccines [BNT162b2 (Pfizer) and mRNA-1273 (Moderna)], incidence of symptomatic COVID-19 infection, antibodies (Abs) response and onset of adverse events (AEs) in a consecutive population of 300 cancer pts, undergoing antiblastic therapies, starting from March 2021. A vaccination point was set up by Cr Hospital, dedicated to cancer pts treated with chemotherapy (CT), TKIs, RT, hormones. Only pts in follow-up or treated with adjuvant hormone are excluded. CT was suspended at least 5 days before and 3 days after vaccination;targeted therapy, immunotherapy and RT are not interrupted. Primary endpoint: Number of symptomatic pts affected by COVID-19, diagnosed 7-60 days after the 2nddose of vaccines. The infection is defined according to the FDA criteria combined with a positive nasopharyngeal swab. Secondary endpoints: Abs variation at different timepoints compared to baseline;vaccine-related adverse events;duration of abs, up to 12 months after 2nd dose;correlation between effectiveness of vaccines and antiblastic treatments, tumor burden, PS ECOG. Statistical analysis: The primary objective will be tested by non-inferiority one-single proportion test, compared with the value of 95% observed in the vaccine registration trials. The hypothesis of vaccine inferiority in the trial population is rejected if a rate of protection conferred by the vaccine is observed in 89% of the sample size. Results Preliminary results will be available in July 2021. Clinical trial identification: NCT04878796. Legal entity responsible for the study: The authors. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.