Humoral and cellular responses to mRNA-based COVID-19 booster vaccinations in patients with solid neoplasms under active treatment.

BACKGROUND: Patients with cancer are at high risk for severe coronavirus disease 2019 (COVID-19) infection. Knowledge regarding the efficacy of the messenger RNA (mRNA) vaccines in actively treated cancer patients is limited as they had been excluded from the pivotal studies of these vaccines. We evaluated humoral and cellular immune responses in cancer patients after double vaccination and a booster dose and identified disease- and treatment-related factors associated with a reduced immune response. We also documented the number and outcome of breakthrough infections. PATIENTS AND METHODS: Patients with metastatic solid malignancies undergoing active treatment were included if they had received two doses of the severe acute respiratory syndrome coronavirus 2 mRNA vaccines BNT162b2 or mRNA-1273 and a booster dose. Other causes of immunosuppression and previous COVID-19 infections (positive anti-nucleocapsid titers) were exclusion criteria. Anti-spike antibodies, neutralizing antibodies (nAbs) and T-cell responses were assessed about 6 months after the two-dose vaccination and 4 weeks after the booster. RESULTS: Fifty-one patients had pre-booster and 46 post-booster measurements. Anti-spike titers after two vaccine doses were highly variable and significantly lower in older patients, during treatment with chemotherapy compared to targeted and endocrine treatments and in patients with low CD4+ or CD19+ cell counts. The booster dose led to a significant increase in anti-spike antibodies and nAbs, achieving almost uniformly high titers, irrespective of baseline and treatment factors. The cellular immune response was also significantly increased by the booster, however generally more stable and not influenced by baseline factors and treatment type. Seventeen patients (33%) experienced breakthrough infections, but none required hospital care or died from COVID-19. CONCLUSIONS: An mRNA vaccine booster dose is able to increase humoral and cellular immune responses and to overcome the immunosuppressive influence of baseline and treatment factors in cancer patients. Breakthrough infections were uniformly mild in this vaccinated high-risk population.

Nelfinavir and lenalidomide/dexamethasone in patients with lenalidomide-refractory multiple myeloma. A phase I/II Trial (SAKK 39/10).

The antiretroviral agent nelfinavir has antimyeloma activity and can overcome resistance to bortezomib. Our phase I/II trial investigated whether adding nelfinavir to lenalidomide-dexamethasone can overcome lenalidomide resistance in lenalidomide-refractory multiple myeloma (MM). Twenty-nine patients were included (high-risk cytogenetic aberrations 31%; ≥2 prior therapy lines 93%; lenalidomide-bortezomib double-refractory 34%). Twenty-four patients (83%) had prior bortezomib and 10 (34%) were lenalidomide-bortezomib double-refractory. They received four cycles of nelfinavir 2500 mg/day with standard-dose lenalidomide (25 mg days 1-21) and dexamethasone (40/20 mg days 1, 8, 15, 22). Minor response or better was achieved in 16 patients (55%; 95% CI 36-74%), including 40% of those who were lenalidomide-bortezomib double-refractory, and partial response or better in nine patients (31%; 95% CI 15-51%). Median progression-free survival was 3.4 (95% CI 2.0-4.9) months and median overall survival 21.6 (13.0-50.1) months. Lenalidomide-related pneumonitis, pneumonia, and neutropenic fever occurred, but there were no unexpected adverse events. Peripheral blood mononuclear cells showed a 45% (95% CI 40-51%) reduction in total proteasome activity from baseline and significant induction of unfolded protein response and autophagy. Thus, nelfinavir-lenalidomide-dexamethasone is an active oral combination in lenalidomide-refractory MM.