Insights From Early Clinical Trials Assessing Response to mRNA SARS-CoV-2 Vaccination in Immunocompromised Patients

Clinical characteristics and COVID-19-related outcomes of immunocompromised patients receiving tixagevimab/cilgavimab pre-exposure prophylaxis in Japan

OBJECTIVE

Tixagevimab/cilgavimab is a cocktail of two long-acting monoclonal antibodies approved for pre-exposure prophylaxis (PrEP) of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection (cause of coronavirus disease 2019 [COVID-19]) in immunocompromised (IC) or high-risk patients. We investigated the patient characteristics and clinical outcomes of IC patients administered tixagevimab/cilgavimab for PrEP in real-world use in Japan.

METHODS

This observational study used anonymous secondary data from Real-World Data Co., Ltd. for IC patients aged ≥12 years administered tixagevimab/cilgavimab between September 2022 and September 2023. We analyzed the baseline characteristics and event-rates of COVID-19-related clinical outcomes within 6 months of administration.

RESULTS

Data were analyzed for 397 IC patients. About half (53.4 %) were male and the median age was 71.0 (interquartile range 61.0, 77.0) years. Malignancy (97.2 %), cardiovascular disease (71.3 %), and diabetes (66.5 %) were frequent comorbidities. Systemic corticosteroids and immunosuppressants were prescribed to 87.4 % and 24.9 %, respectively. The two most common target clinical conditions were active therapy for hematologic malignancies (88.2 %) and treatment with B cell-depleting therapies (57.4 %). The event-rates per 100 person-months (95 % confidence interval; number) for medically attended COVID-19, COVID-19 hospitalization, in-hospital mortality due to COVID-19, and all-cause death were 4.14 (3.06-5.48; n = 49), 1.74 (1.09-2.64; n = 22), 0.07 (0.00-0.42; n = 1), and 0.60 (0.26-1.17; n = 8), respectively.

CONCLUSION

This is the first report using a multicenter database to describe the clinical characteristics and COVID-19-related outcomes of IC patients administered with tixagevimab/cilgavimab in real-world settings in Japan. This cohort of IC patients who received tixagevimab/cilgavimab included many elderly patients with comorbidities.

Convalescent Plasma Therapy in Immunocompromised Patients Infected With the BA.1 or BA.2 Omicron SARS-CoV-2

The emergence of SARS-CoV-2 Omicron variant has led to a complete reconfiguration of the therapeutic landscape, with all monoclonal antibodies having lost any neutralization activity. We report here a case series of 75 immunocompromised patients infected by the Omicron variant who benefited from COVID-19 convalescent plasma (CCP). At Day 28, the overall survival was 76% (95% CI 67-86) with no significant difference in the clinical outcome between patients with hematological malignancies, solid organ transplantation or autoimmune diseases. No safety concern was reported during the course of the study. These results showed that CCP is well tolerated and represents a treatment option for immunocompromised patients who remain highly impacted by the COVID19 epidemic.

COVID‑19 antibody production by vaccination in chemotherapy with CD20 antibody for B‑cell lymphoma

Most hematologic diseases are immunosuppressed, either by the disease itself or by treatment. As such, the implementation of vaccination is largely at the discretion of the attending physician. In this context, an objective measure is needed, therefore the index of vaccination against coronavirus disease 2019 (COVID-19) in B-cell lymphomas treated with antibody therapy against CD20 (including after the completion of therapy) was examined. A total of 40 patients with B-cell lymphoma during or after antibody therapy against CD20 were vaccinated twice with the BNT162b2 messenger RNA (mRNA) COVID-19 vaccine (Pfizer, Inc. and BioNTech SE.) at 3-week intervals and then again six months later with the same vaccine or mRNA-1273 (Moderna, Inc.). Antibody testing was conducted ~1 month after the third vaccination. Analysis was performed using the antibody titers to the anti-spike immunoglobulin assay, with a titer of 0.8 U/ml or higher (considered positive) and a titer of 264 U/ml or higher (considered the value at which the efficacy of the vaccine can be fully expected). Significant factors of antibody acquisition were identified when i) antibody titers were 0.8 U/ml or higher (CD4 ≥400/µl), ii) no anti-CD20 antibody maintenance therapy was undertaken (CD19 ≥100/µl), iii) patients were not on treatment (CD4 ≥400/µl), or 4) at least six months had passed since treatment ended (CD19 ≥100/µl). When antibody titers were 264 U/ml or higher, the treatment method, the stage of the primary disease and other factors related to the condition treatment method of the patient were relevant. When these were analyzed by multivariate analysis, the significant factor when antibody titers were set to 0.8 U/ml was CD19 ≥100/µl. In contrast, when setting them to 264 U/ml or higher, CD4 ≥400/µl was not significant, but there was a tendency for it to be related. The findings of the present study on vaccine-induced antibody acquisition in patients with B-cell lymphoma indicated that it is desirable to have a CD19 titer of at least 100/µl and a CD4 titer of at least 400/µl (both conditions should be met), and that no maintenance therapy with anti-CD20 antibody should be administered for at least six months after the last treatment or completion of the treatment. Interestingly, when the criteria for antibody titers were compared between 0.8 U/ml, where antibody titer is detected, and 264 U/ml, where vaccine efficacy is expected, several key factors were different. It is possible that these key factors may change depending on the antibody titer used as a criterion.

Vaccine effectiveness of the mRNA-1273 3-dose primary series against COVID-19 in an immunocompromised population: A prospective observational cohort study

BACKGROUND

Data on the effectiveness of the 3-dose mRNA-1273 primary series are limited, particularly in comparison to 2 doses. Given suboptimal COVID-19 vaccine uptake among immunocompromised populations, it is important to monitor the effectiveness of fewer than the recommended doses in this population.

METHODS

We conducted a matched cohort study at Kaiser Permanente Southern California to evaluate the relative vaccine effectiveness (rVE) of the 3-dose series vs 2 doses of mRNA-1273 in preventing SARS-CoV-2 infection and severe COVID-19 outcomes among immunocompromised individuals.

RESULTS

We included 21,942 3-dose recipients who were 1:1 matched with randomly selected 2-dose recipients (third doses accrued 08/12/2021-12/31/2021, with follow-up through 01/31/2022). Adjusted rVE of 3 vs 2 doses of mRNA-1273 against SARS-CoV-2 infection, COVID-19 hospitalization, and COVID-19 hospital death were 55.0 % (95 % CI: 50.8-58.9 %), 83.0 % (75.4-88.3 %), and 87.1 % (30.6-97.6 %), respectively.

CONCLUSION

Three doses of mRNA-1273 were associated with a significantly higher rVE against SARS-CoV-2 infection and severe outcomes, compared to 2 doses. These findings were consistent across subgroups of demographic and clinical characteristics, and mostly consistent across subgroups of immunocompromising conditions. Our study highlights the importance of completing the 3-dose series for immunocompromised populations.