Management of chronic lymphocytic leukemia in Italy during a one year of the COVID-19 pandemic and at the start of the vaccination program. A Campus CLL report

Management of infections for patient treated with ibrutinib in clinical practice

Ibrutinib, a highly effective inhibitor of the Bruton tyrosine kinase, has significantly transformed the therapeutic approach in chronic lymphocytic leukemia (CLL). Despite these advancements, the disease continues to be characterized by immune dysfunction and increased susceptibility to infections, with mortality rates from infections showing no significant improvement over the past few decades. Therefore, timely prevention, recognition, and treatment of infections remains an important aspect of the standard management of a patient with CLL. A panel of hematologists with expertise in CLL met to discuss existing literature and clinical insights for the management of infectious in CLL undergoing ibrutinib treatment. Despite not being a fully comprehensive review on the topic, this work provides a set of practical recommendations that can serve as a guide to healthcare professionals who manage these patients in their daily clinical practice.

Severe infections in patients with chronic lymphocytic leukemia included in trials investigating BTK and BCL2 inhibitors

Bruton tyrosine kinase inhibitors (BTKi) and the BCL-2 inhibitor venetoclax have significantly improved the prognosis of patients with chronic lymphocytic leukemia (CLL). However, the incidence of severe infections in patients receiving these agents needs to be better understood. Our review aimed to provide an overview of grade ≥3 infections in patients with CLL who received BTKi and venetoclax-based therapy in prospective trials. Infection rates were influenced by the age of patients and the duration of follow-up. For treatment-naive (TN) patients receiving BTKi, infection rates ranged between 11.4 % and 27.4 % and were close to 30 % in relapsed/refractory (R/R) patients. TN and R/R patients receiving fixed-duration venetoclax-based treatments showed variable rates, with maximum values around 20 %. Opportunistic and fatal infections were uncommon. In conclusion, infections remain a concern in patients with CLL receiving targeted agents. A better definition of factors increasing infection vulnerability could help identify those patients who require infection prophylaxis.

Real-life diagnostic and therapeutic approach to CLL: a 2022 update from an expert panel in Tuscany

A panel of chronic lymphocytic leukemia (CLL) experts from Tuscany propose a real-life diagnostic and therapeutic approach CLL that considers the role of genomic and somatic prognostic factors in risk stratification and treatment decisions. Safety and efficacy of new agents has been demonstrated now not only in clinical trials but also in many real-world series. The BTK inhibitors, ibrutinib and acalabrutinib, and BH3 mimetic venetoclax are now indicated as first-line therapy and chemoimmunotherapy can be spared to the majority of CLL patients, thus preventing unnecessary hematological and non-hematological toxicity and second primary tumors. For treatment, FISH for 17 p and P53 mutational status are essential. IGHV mutation can be done at diagnosis or before treatment. Echography is the gold standard radiological investigation in CLL, at both diagnosis and response evaluation. Chemotherapy is virtually abandoned. Age, genetic risk, and patient comorbidities have to be carefully evaluated for treatment decision. With the availability of different drugs, there is a need for a uniform and shared approach in daily therapeutic choice. The proposed approach is based on current evidence and guidelines as well as results from clinical trials and daily clinical experience.

COVID-19 in Patients with Chronic Lymphocytic Leukemia: What Have We Learned?

BACKGROUND

Chronic lymphocytic leukemia (CLL) is a prevalent hematological malignancy (HM) characterized by inherent immunodeficiency, which is further pronounced by disease-directed therapy. The COVID-19 pandemic has had devastating outcomes, and although its impact has diminished over time, it continues to be a cause of significant morbidity and mortality, particularly among immunodeficient patients.

SUMMARY

In this review, we describe mechanisms of immune dysfunction in CLL in relation to COVID-19, provide an overview of the clinical outcomes of the disease in this patient population, and identify risk factors associated with severe morbidity and mortality. Additionally, we acknowledge the influence of the rapidly evolving landscape of new disease variants. The review further delineates the humoral and cellular responses to vaccination and their clinical efficacy in preventing COVID-19 in CLL patients. Moreover, we explore potential approaches to enhance these immune responses. Pre- and post-exposure prophylaxis strategies are discussed, along with description of common agents in the treatment of the disease in both outpatient and inpatient setting. Throughout the review, we emphasize the interplay between novel therapies for CLL and COVID-19 outcomes, prevention, and treatment and describe the impact of COVID-19 on the utilization of these novel agents. This information has the potential to guide clinical decision making in the management CLL patients.

KEY MESSAGES

CLL patients are at risk for severe COVID-19 infection. Vaccinations and COVID-19 directed therapy have improved outcomes in patients with CLL, yet clinical challenges persist.

COVID-19 in Adult Patients with Hematological Malignancies-Lessons Learned after Three Years of Pandemic

The COVID-19 pandemic is undoubtedly the most difficult health challenge of the 21st century with more than 600 million laboratory-confirmed SARS-CoV-2 infections and over 6.5 million deaths worldwide. The coronavirus pandemic contributed to rapid development of mRNA vaccines, which, along with new antiviral drugs, have been the subject of extensive research for many decades. Nevertheless, elderly, multi-morbid and immunocompromised patients continue to face a more severe clinical course and a higher risk of death from COVID-19, even now that the risk of COVID-19 in the general population is significantly reduced due to the introduction of global vaccination strategies. In this paper, we present the mechanisms of increased susceptibility to infectious complications and the evolution of the clinical course of COVID-19 in patients with hematological malignancies, taking into account the mutation of the virus and the introduction of vaccines and new antiviral drugs. We also present current recommendations for prophylactic and therapeutic management in patients with hematological malignancies.

Cellular and humoral response to the fourth BNT162b2 mRNA COVID-19 vaccine dose in patients with CLL

We assessed the humoral and cellular response to the fourth BNT162b2 mRNA COVID-19 vaccine dose in patients with CLL. A total of 67 patients with CLL and 85 age matched controls tested for serologic response and pseudo-neutralization assay. We also tested the functional T-cell response by interferon gamma (IFNγ) to spike protein in 26 patients. Two weeks after the fourth vaccine antibody serologic response was evident in 37 (55.2%) patients with CLL, 20 /22 (91%) of treatment naïve, and 9/32 (28%) patients with ongoing therapy, compared with 100% serologic response in age matched controls. The antibody titer increased by 10-fold in patients with CLL, however, still 88-folds lower than age matched controls. Predictors of better chances of post fourth vaccination serologic response were previous positive serologies after second, third, and pre-fourth vaccination, neutralizing assay, and treatment naïve patients. T-cell response improved from 42.3% before the fourth vaccine to 84.6% 2 weeks afterwards. During the time period of 3 months after the fourth vaccination, 14 patients (21%) developed COVID-19 infection, all recovered uneventfully. Our data demonstrate that fourth SARS-CoV-2 vaccination improves serologic response in patients with CLL to a lesser extent than healthy controls and induces functional T-cell response.

Immune correlates of protection by vaccine against SARS-CoV-2 in patients with chronic lymphocytic leukaemia

In chronic lymphocytic leukaemia (CLL) the efficacy of SARS-CoV-2 vaccination remains unclear as most studies have focused on humoral responses. Here we comprehensively examined humoral and cellular responses to vaccine in CLL patients. Seroconversion was observed in 55.2% of CLL with lower rate and antibody titres in treated patients. T-cell responses were detected in a significant fraction of patients. CD4⁺ and CD8⁺ frequencies were significantly increased independent of serology with higher levels of CD4⁺ cells in patients under a Bruton tyrosine kinase (BTK) or a B-cell lymphoma 2 (BCL-2) inhibitor. Vaccination skewed CD8⁺ cells towards a highly cytotoxic phenotype, more pronounced in seroconverted patients. A high proportion of patients showed spike-specific CD4⁺ and CD8⁺ cells producing interferon gamma (IFNγ) and tumour necrosis factor alpha (TNFα). Patients under a BTK inhibitor showed increased production of IFNγ and TNFα by CD4⁺ cells. Vaccination induced a Th1 polarization reverting the Th2 CLL T-cell profile in the majority of patients with lower IL-4 production in untreated and BTK-inhibitor-treated patients. Such robust T-cell responses may have contributed to remarkable protection against hospitalization and death in a cohort of 540 patients. Combining T-cell metrics with seroprevalence may yield a more accurate measure of population immunity in CLL, providing consequential insights for public health.

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.

Response to anti-SARS-CoV-2 mRNA vaccines in multiple myeloma and chronic lymphocytic leukemia patients

Multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) patients have increased morbidity and mortality rates of COVID-19 due to immunosuppression associated with the disease and ongoing therapy. The same immune impairment accompanying CLL and MM also affects suboptimal vaccine response. The study assessed the effectiveness of the humoral and T cell-mediated immunity following mRNA COVID-19 vaccination (using either BNT162b2 or mRNA-1273) in short-term (2-5 weeks after second dose) and long-term follow-up (12 weeks after vaccination). Between March and August 2021, blood samples were obtained from 62 CLL and 60 MM patients from eight different hematology departments in Poland. Total anti-RBD antibodies were detected in 37% MM patients before vaccination, increased to 91% and 94% in short- and long-term follow-up, respectively. In CLL, serological responses were detectable in 21% of patients before vaccination and increased to 45% in the short-term and 71% in long-term observation. We detected a tendency to higher frequencies of specific CD8+ T cells against SARS-CoV-2 after vaccination compared to samples before vaccination in MM patients and no changes in frequencies of specific T cells in CLL patients. Our study provides novel insights into mRNA vaccination efficacy in immunocompromised MM and CLL patients, and our findings highlight that specific CD8+ T cells against SARS-CoV-2 might be induced by vaccination but do not correlate positively with serological responses.

Current perspectives regarding SARS-CoV-2 vaccination in chronic lymphocytic leukemia

In immunocompetent people, the mRNA vaccines BNT162b2 and mRNA‐1273 have been shown to be safe and effective against coronavirus disease of 2019 (COVID‐19). However, results of cohort studies and meta‐analyses have indicated that the degree of humoral response to SARS‐CoV‐2 vaccines in patients with chronic lymphocytic leukemia (CLL) appears to be lower than that observed in the general population. These inadequate responses are mainly related to the disease itself and to the immunosuppressive effect of therapies administered. In the specific context of CLL, enrolling patients with sub‐optimal vaccine‐response in pivotal vaccine trials could be considered as an appropriate approach to improve response to the COVID‐19 vaccine. These clinical trials should also address the issues of regularity and timing of vaccine booster doses or re‐vaccinations, especially in patients undergoing therapy with pathway‐targeting agents and anti‐CD20 monoclonal antibodies. However, since hypogammaglobulinemia is a serious consequence of CLL, patients who do not have a detectable antibody response should be natural candidates for preventive antibody therapy.

Chronic Lymphocytic Leukemia in the SARS-CoV-2 Pandemic

PURPOSE OF REVIEW

Chronic lymphocytic leukemia (CLL) is the most frequent lymphoproliferative disease in the elderly of the western world. Immune defective responses and treatment can worsen the immune system's competence of CLL patients. Consequently, they may present a higher incidence of recurrent severe infections, second malignancies, and reduced efficacy of vaccines. The outbreak of COVID-19 is an ongoing pandemic, and patients with comorbidities experience more severe forms of the disease. Hematological malignancies are associated with higher case fatality rates (CFRs) than other cancers. Knowledge about COVID-19 incidence, clinical course, and immune response to the infection and vaccination in CLL may contribute to design strategies that improve the outcomes of patients in the future.

RECENT FINDINGS

The prevalence of SARS-CoV-2 positivity in CLL is not significantly higher than seen in the general population. CFRs for CLL patients are 16.5-fold more elevated than the median reported worldwide and even higher in older patients, those who require hospitalization have significant comorbidities or need oxygen therapy. CLL status decreases the anti-SARS-CoV-2 positivity after infection or vaccination by around 40%, and the spike-specific antibody titers are 74-fold lower than healthy age-matched controls. The response rate to COVID-19 vaccines is even worse in patients with active CLL-directed therapies like BTKi, BCL-2 antagonists, or anti-CD20 monoclonal antibodies. CLL patients are at a greater risk of death from COVID-19. Inherent immunosuppression of CLL and immune deficiencies caused by treatment significantly decrease the ability to produce natural or vaccine-induced anti-SARS-CoV-2 immune responses.