Pembrolizumab versus placebo as adjuvant therapy in completely resected stage IIB or IIC melanoma (KEYNOTE-716): a randomised, double-blind, phase 3 trial.

BACKGROUND: Pembrolizumab prolongs progression-free and overall survival among patients with advanced melanoma and recurrence-free survival in resected stage III disease. KEYNOTE-716 assessed pembrolizumab as adjuvant therapy in patients with completely resected, high-risk, stage II melanoma. We report results from the planned first and second interim analyses for recurrence-free survival. METHODS: In this double-blind, randomised, placebo-controlled phase 3 study, involving 160 academic medical centres and hospitals in 16 countries (Australia, Belgium, Brazil, Canada, Chile, France, Germany, Israel, Italy, Japan, Poland, South Africa, Spain, Switzerland, the UK, and the USA), patients aged 12 years or older with newly diagnosed, completely resected stage IIB or IIC melanoma (TNM stage T3b or T4 with a negative sentinel lymph node biopsy) were recruited. Eligible patients were randomly assigned (1:1), in blocks of four and stratified by T-category (3b, 4a, and 4b) and paediatric status (age 12-17 years vs ≥18 years), using an interactive response technology system to intravenous pembrolizumab 200 mg (2 mg/kg in paediatric patients) or placebo every 3 weeks for 17 cycles or until disease recurrence or unacceptable toxicity. All patients, clinical investigators, and analysts were masked to treatment assignment. The primary endpoint was investigator-assessed recurrence-free survival (defined as time from randomisation to recurrence or death) in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment). The primary endpoint was met if recurrence-free survival was significantly improved for pembrolizumab versus placebo at either the first interim analysis (after approximately 128 patients had events) or second interim analysis (after 179 patients had events) under multiplicity control. Safety was assessed in all patients randomly assigned to treatment who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03553836, and is closed to accrual. FINDINGS: Between Sept 23, 2018, and Nov 4, 2020, 1182 patients were screened, of whom 976 were randomly assigned to pembrolizumab (n=487) or placebo (n=489; ITT population). The median age was 61 years (IQR 52-69) and 387 (40%) patients were female and 589 (60%) were male. 874 (90%) of 976 patients were White and 799 (82%) were not Hispanic or Latino. 483 (99%) of 487 patients in the pembrolizumab group and 486 (99%) of 489 in the placebo group received assigned treatment. At the first interim analysis (data cutoff on Dec 4, 2020; median follow-up of 14·4 months [IQR 10·2-18·7] in the pembrolizumab group and 14·3 months [10·1-18·7] in the placebo group), 54 (11%) of 487 patients in the pembrolizumab group and 82 (17%) of 489 in the placebo group had a first recurrence of disease or died (hazard ratio [HR] 0·65 [95% CI 0·46-0·92]; p=0·0066). At the second interim analysis (data cutoff on June 21, 2021; median follow-up of 20·9 months [16·7-25·3] in the pembrolizumab group and 20·9 months [16·6-25·3] in the placebo group), 72 (15%) patients in the pembrolizumab group and 115 (24%) in the placebo group had a first recurrence or died (HR 0·61 [95% CI 0·45-0·82]). Median recurrence-free survival was not reached in either group at either assessment timepoint. At the first interim analysis, grade 3-4 treatment-related adverse events occurred in 78 (16%) of 483 patients in the pembrolizumab groups versus 21 (4%) of 486 in the placebo group. At the first interim analysis, four patients died from an adverse event, all in the placebo group (one each due to pneumonia, COVID-19-related pneumonia, suicide, and recurrent cancer), and at the second interim analysis, one additional patient, who was in the pembrolizumab group, died from an adverse event (COVID-19-related pneumonia). No deaths due to study treatment occurred. INTERPRETATION: Pembrolizumab as adjuvant therapy for up to approximately 1 year for stage IIB or IIC melanoma resulted in a significant reduction in the risk of disease recurrence or death versus placebo, with a manageable safety profile. FUNDING: Merck Sharp & Dohme, a subsidiary of Merck & Co, Kenilworth, NJ, USA.

Persistence of SARS-CoV-2 Infection in Severely Immunocompromised Patients With Complete Remission B-Cell Lymphoma and Anti-CD20 Monoclonal Antibody Therapy: A Case Report of Two Cases.

Immunosuppressant conditions such as hematological malignancies increase the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It has been described in the literature that patients on anti-CD20 maintenance therapies for lymphoid malignancies are susceptible to having recurrent flares together with viral replication or reinfections, although these cases are scarce. These patients are not well represented in randomized controlled trials, and as a consequence, the evidence for the use of certain treatments in this scenario is lacking. We present two cases of patients with B-cell lymphoma on remission and treated with rituximab on maintenance. They developed at least 1 flare of coronavirus disease 2019 (COVID-19) after acute infection and always after receiving rituximab. RT-PCR was positive in the nasopharyngeal swab and also in plasma. Patients were treated during flares with remdesivir, hyperimmune plasma, and corticosteroids. These two cases showed the unresolved problem of COVID-19 in immunosuppressant patients and showed that despite the vast amount of information available on SARS-CoV-2, information in this subgroup of patients is lacking.

Low Levels of Granulocytic Myeloid-Derived Suppressor Cells May Be a Good Marker of Survival in the Follow-Up of Patients With Severe COVID-19

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a disease (coronavirus disease 2019, COVID-19) that may develop into a systemic disease with immunosuppression and death in its severe form. Myeloid-derived suppressive cells (MDSCs) are inhibitory cells that contribute to immunosuppression in patients with cancer and infection. Increased levels of MDSCs have been found in COVID-19 patients, although their role in the pathogenesis of severe COVID-19 has not been clarified. For this reason, we raised the question whether MDSCs could be useful in the follow-up of patients with severe COVID-19 in the intensive care unit (ICU). Thus, we monitored the immunological cells, including MDSCs, in 80 patients admitted into the ICU. After 1, 2, and 3 weeks, we examined for a possible association with mortality (40 patients). Although the basal levels of circulating MDSCs did not discriminate between the two groups of patients, the last measurement before the endpoint (death or ICU discharge) showed that patients discharged alive from the ICU had lower levels of granulocytic MDSCs (G-MDSCs), higher levels of activated lymphocytes, and lower levels of exhausted lymphocytes compared with patients who had a bad evolution (death). In conclusion, a steady increase of G-MDSCs during the follow-up of patients with severe COVID-19 was found in those who eventually died.

Increased Blood Monocytic Myeloid Derived Suppressor Cells but Low Regulatory T Lymphocytes in Patients with Mild COVID-19.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may produce a systemic disease, the coronavirus disease-19 (COVID-19), with high morbidity and mortality. Even though we do not fully understand the interaction of innate and adaptive immunity in the control and complications of the viral infection, it is well recognized that SARS-CoV-2 induces an immunodepression that impairs the elimination of the virus and favors its rapid dissemination in the organism. Even less is known about the possible participation of inhibitory cells of the innate immune system, such as the myeloid-derived suppressor cells (MDSCs), or the adaptive immune system, such as the T regulatory cells (Tregs). That is why we aimed to study blood levels of MDSCs, as well as lymphocyte subpopulations, including Tregs, and activated (OX-40+) and inhibited (PD-1) T lymphocytes in patients with mild COVID-19 in comparison with data obtained from control donors. We have found that 20 hospitalized patients with COVID-19 and no health history of immunosuppression had a significant increase in the number of peripheral monocytic MDSCs (M-MDSC), but a decrease in Tregs, as well as an increase in the number of inhibited or exhausted T cells, whereas the number of activated T cells was significantly decreased compared with that from 20 healthy controls. Moreover, there was a significant negative correlation (r = 0.496) between the number of M-MDSC and the number of activated T cells. Therefore, M-MDSC rather than Tregs may contribute to the immunosuppression observed in patients with COVID-19.