COVID-19 and Chronic Lymphocytic Leukemia: Where We Stand Now

Omicron related COVID-19 prevention and treatment measures for patients with hematological malignancy and strategies for modifying hematologic treatment regimes

The Omicron variant of SARS-CoV-2 has rapidly become the dominant strain worldwide due to its high transmissibility, although it appears to be less pathogenic than previous strains. However, individuals with hematological malignancy (HM) and COVID-19 remain susceptible to severe infection and mortality, especially those with chronic lymphocytic leukemia (CLL) and those undergoing chimeric antigen receptor T-cell (CAR-T) treatment. Hematologists should thoroughly assess the severity of the patient's hematological disease and the potential risk of SARS-CoV-2 infection before initiating chemotherapy or immunosuppressive treatment. Vaccination and booster doses are strongly recommended and patients with a poor vaccine response may benefit from long-acting COVID-19 neutralizing monoclonal antibodies (such as Evusheld). Early use of small molecule antiviral drugs is recommended for managing mild COVID-19 in HM patients and those with severe immunodeficiency may benefit from SARS-CoV-2 neutralizing monoclonal antibody therapy and high-titer COVID-19 convalescent plasma (CCP). For moderate to severe cases, low-dose glucocorticoids in combination with early antiviral treatment can be administered, with cytokine receptor antagonists or JAK inhibitors added if the condition persists or worsens. In the treatment of hematological malignancies, delaying chemotherapy is preferable for CLL, acute leukemia (AL), and low-risk myelodysplastic syndrome (MDS), but if the disease progresses, appropriate adjustments in dosage and frequency of treatment are required, with the avoidance of anti-CD20 monoclonal antibody, CAR-T and hematopoietic stem cell transplantation (HSCT). Patients with chronic myelocytic leukemia (CML) and myeloproliferative neoplasms (MPNs) can continue current treatment. What's more, non-drug protective measures, the development of new vaccines and antiviral drugs, and monitoring of mutations in immunocompromised populations are particularly important.

Multiple COVID-19 vaccine doses in CLL and MBL improve immune responses with progressive and high seroconversion

Patients with chronic lymphocytic leukemia (CLL) or monoclonal B-lymphocytosis (MBL) have impaired response to COVID-19 vaccination. A total of 258 patients (215 with CLL and 43 with MBL) had antispike antibody levels evaluable for statistical analysis. The overall seroconversion rate in patients with CLL was 94.2% (antispike antibodies ≥50 AU/mL) and 100% in patients with MBL after multiple vaccine doses. After 3 doses (post-D3) in 167 patients with CLL, 73.7% were seropositive, 17.4% had antispike antibody levels between 50 and 999 AU/mL, and 56.3% had antispike antibody levels ≥1000 AU/mL, with a median rise from 144.6 to 1800.7 AU/mL. Of patients who were seronegative post-D2, 39.7% seroconverted post-D3. For those who then remained seronegative after their previous dose, seroconversion occurred in 40.6% post-D4, 46.2% post-D5, 16.7% post-D6, and 0% after D7 or D8. After seroconversion, most had a progressive increase in antispike antibody levels. Neutralization was associated with higher antispike antibody levels, more vaccine doses, and earlier severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants; neutralizing antibody against early clade D614G was detected in 65.3%, against Delta in 52.0%, and against Omicron in 36.5%. SARS-CoV-2-specific T-cell production of interferon γ and interleukin 2 occurred in 73.9% and 60.9%, respectively, of 23 patients tested. After multiple vaccine doses, by multivariate analysis, immunoglobulin M ≥0.53 g/L, immunoglobulin subclass G3 ≥0.22 g/L and absence of current CLL therapy were independent predictors of positive serological responses. Multiple sequential COVID-19 vaccination significantly increased seroconversion and antispike antibody levels in patients with CLL or MBL.

SARS-CoV-2 infection in patients with chronic lymphocytic leukemia: The Italian Hematology Alliance on COVID-19 cohort

COVID-19, the disease caused by SARS-CoV-2, is still afflicting thousands of people across the globe. Few studies on COVID-19 in chronic lymphocytic leukemia (CLL) are available. Here, we analyzed data from the CLL cohort of the Italian Hematology Alliance on COVID-19 (NCT04352556), which included 256 CLL patients enrolled between 25 February 2020 and 1 February 2021. Median age was 70 years (range 38-94) with male preponderance (60.1%). Approximately half of patients (n = 127) had received at least one line of therapy for CLL, including 108 (83.7%) who were on active treatment at the time of COVID-19 or received their last therapy within 12 months. Most patients (230/256, 89.9%) were symptomatic at COVID-19 diagnosis and the majority required hospitalization (n = 176). Overall, after a median follow-up of 42 days (IQR 24-96), case fatality rate was 30.1%, and it was 37.5% and 24.4% in the first (25 February 2020-22 June 2020) and second wave (23 June 2020-1 February 2021), respectively (p = 0.03). At multivariate analysis, male sex (HR 1.82, 95% CI 1.03-3.24, p = 0.04), age over than 70 years (HR 2.23, 95% CI 1.23-4.05, p = 0.01), any treatment for CLL given in the last 12 months (HR 1.72, 95% CI 1.04-2.84, p = 0.04) and COVID-19 severity (severe: HR 5.66, 95% CI 2.62-12.33, p < 0.0001; critical: HR 15.99, 95% CI 6.93-36.90, p < 0.0001) were independently associated with poor survival. In summary, we report a dismal COVID-related outcome in a significant fraction of CLL patients, that can be nicely predicted by clinical parameters.

Long-term effect of venetoclax therapy in a patient with the transformation of chronic lymphocytic leukemia into Richter's syndrome

Richter's syndrome (RS) is the next step in the progression of chronic lymphocytic leukemia (CLL) progression. It leads to reduced overall patient survival, the necessity of aggressive chemotherapy and a decline in the quality of life. The first line of RS treatment includes traditional chemotherapy such as rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone. However, during the past decade, novel targeted agents added to the therapy dramatically changed the treatment outcome for patients with RS. In our case, we describe a patient with CLL that had progressed to RS and achieved complete remission that lasted > 15 months with venetoclax monotherapy.

Managing the Risk of Infection in Chronic Lymphocytic Leukemia in the Era of New Therapies

PURPOSE OF REVIEW

Patients diagnosed with CLL have an increased susceptibility to infections. Over the years, there has been a shift of the treatment arsenal to an increasing use of chemotherapy-free regimens, particularly small molecule inhibitors. These therapies have proven to be effective and have a favorable toxicity profile. Infections continue to represent a significant complication in the era of novel therapies.

RECENT FINDINGS

Recent studies continue to bring new insights into the effects of modern therapies on the immune system. Evidence supporting infection prevention strategies is scarce. We will review the available recommendations to prevent infections in patients with CLL treated with novel therapies. New CLL therapies are broadly adopted in routine practice, requiring optimization of their side effects. Timely prevention, recognition, and treatment of infections should remain an important aspect of the standard management of a patient with CLL.