Limited T cell response to SARS-CoV-2 mRNA vaccine among patients with cancer receiving different cancer treatments.

INTRODUCTION: Patients with cancer (PC) are at high risk of acquiring COVID-19 and can develop more serious complications. Deeper understanding of vaccines immunogenicity in this population is crucial for adequately planning vaccines programs. The ONCOVac study aimed to comprehensively assess the immunogenicity of mRNA-1273 vaccine in terms of humoral and cellular response. METHODS: We conducted a prospective, single-center study including patients with solid tumours treated with cyclin-dependent kinases 4 and 6 inhibitors (CDK4/6i), immunotherapy (IT) or chemotherapy (CT). Patients were enrolled previously to vaccination with mRNA-1273. We also involved health care workers (HCW) to serve as a control group. We took blood samples before first dose administration (BL), after first dose (1D), and after second dose (2D). The primary objective was to compare the rate and magnitude of T cell response after second dose whereas safety and humoral response were defined as secondary objectives. We also collected patient reported outcomes after both the first and second vaccine dose and a six-month follow-up period to diagnose incident COVID-19 cases was planned. RESULTS: The rate of specific anti-S serologic positivity (anti-S IgG cut-off point at 7,14 BAU/mL) was significantly higher in HCW compared to PC after 1D (100% versus 83.8%; p = 0.04), but similar after 2D (100% versus 95.8%; p = 0.5). This difference after 1D was driven by PC treated with CT (100% versus 64.5%; p = 0.001). Cellular response after 2D was significantly lower in PC than in HCW for both CD4+ (91.7% versus 59.7%; p = 0.001) and CD8+ (94.4% versus 55.6%; p < 0.001) T cells. We found a difference on pre-existing CD4+ T cell response in HCW comparing to PC (36% and 17%, p = 0.03); without difference in pre-existing CD8+ T cell response (31% and 23%, p = 0.5). After excluding patients with pre-existing T cell response, PC achieved even lower CD4+ (50.9% versus 95.5%, p < 0.001) and CD8+ (45.5% versus 95.5%, p < 0.001) T cell response compared with HCW. Regarding safety, PC reported notably more adverse events than HCW (96.6% versus 69.2%, p < 0.001). CONCLUSION: We demonstrated that PC showed a similar humoral response but a lower T cell response following two doses of mRNA-1273 vaccination. Further studies are needed to complement our results and determine the implication of low T cell response on clinical protection of PC against COVID-19.

High risk of thrombosis in patients with advanced lung cancer harboring rearrangements in ROS1.

INTRODUCTION: Based on the high incidence of thromboembolic events (TEs) observed in lung adenocarcinomas with ALK translocations and taking into account the biological proximity of ROS1 and ALK, we conducted a retrospective analysis of patients with advanced lung carcinoma carrying rearrangements in ROS1 from 23 centres in Spain and one centre in Portugal. METHODS: The main objective of the study was to analyse the incidence of TE in this population, looking for predictive risk factors, and its impact on overall survival. RESULTS: A total of 58 patients were included. The incidence of TEs throughout the disease was 46.6% (n = 27) with a median follow-up of 19 months (range: 1-78 months) and a median overall survival of 52 months in the total population and 50 months for the patients presenting TEs, with a hazards ratio of 1.12 (95% confidence interval: 0.47-2.65) p = 0.78. The majority of the events were venous (n = 24; 89%) and occurred in the ambulatory setting (n = 18; 67%). Almost half of the patients (n = 13; 48%) presented the TE in the peri-diagnostic period. CONCLUSIONS: The high incidence of thrombosis, especially during the cancer diagnosis process, requires special attention from a clinician. Despite the limitations of such a small descriptive study, its results are in accordance with previously reported data. It would be important to design prospective studies of antithrombotic prophylaxis in this population because of their possible impact in reducing the risk of TEs.