A snapshot of the immunogenity, efficacy and safety of a full course of BNT162b2 anti-SARS-CoV-2 vaccine in cancer patients treated with PD-1/PD-L1 inhibitors: a longitudinal cohort study.

Lasagna, A.; Agustoni, F.; Percivalle, E.; Borgetto, S.; Paulet, A.; Comolli, G.; Sarasini, A.; Bergami, F.; Sammartino, J.C.; Ferrari, A.; Zavaglio, F.; Arena, F.; Lilleri, D.; Secondino, S.; Falzoni, M.; Schiavo, R.; Klersy, C.; Cavanna, L.; Baldanti, F.; Pedrazzoli, P.; Cassaniti, I.

BACKGROUND: Very few cancer patients were enrolled in COVID-19 vaccine studies. In order to address this gap of knowledge, real world studies are mandatory. Aim of this study was to assess both humoral and cellular response after a mRNA vaccination schedule. PATIENTS AND METHODS: Eighty-eight consecutive cancer patients treated with PD-1/PD-L1 inhibitors were enrolled from the beginning of the vaccination campaign for frail patients. Blood samples for humoral and cell-mediated immune response evaluation were obtained before vaccination (T0), before the second administration (T1) and 21 days after the second dose (T2). The primary end-point was the evaluation of the percentage of participants showing a significant increase in SARS-CoV-2 specific T cells, measured by an ELISPOT assay, after the second dose of BNT162b2 vaccine. The proportion of patients who reached the primary endpoint is computed together with its exact binomial 95% confidence interval (95%CI). RESULTS: In SARS-CoV-2 naïve subjects, Spike-specific T-cell response was almost undetectable at T0 (median 0.0 IFNγ SFU/million PBMC IQR 0-7.5) and significantly increased at T1 and T2 (median 15.0 IFNγ SFU/million PBMC 25th-75th 0-40 vs 90 IFNγ SFU/million PBMC 25th-75th 32.5-224; respectively) (p<0.001). Focusing on naïve and experienced SARS-CoV-2 subjects no differences were reported both in terms of CD4 and CD8-specific T-cell response, suggesting that BNT162b2 is able to elicit both adaptive responses after complete vaccination schedule, regardless previous SARS-CoV-2 exposure. The level of SARS-CoV-2 NT Abs was low at T1 in SARS-CoV-2 naïve subjects [median 1:5 (IQR 1:5-1:20)] but reached a significantly higher median 1:80 (25th-75th 1:20-1:160) at T2 (p<0.0001). Moreover no COVID-19 cases were documented throughout the period of study. CONCLUSIONS: Our data have demonstrated that the administration of a full course of BNT162b2 vaccine elicited a sustained immune response against SARS-CoV-2 regardless to the type of cancer and/or the type of ICIs.