Clinical efficacy and tolerability of venetoclax plus rituximab in patients with relapsed or refractory chronic lymphocytic leukemia-a real-world analysis of the Polish Adult Leukemia Study Group.

The results of the MURANO trial showed encouraging progression-free survival (PFS) and overall survival (OS) in relapsed/refractory chronic lymphocytic leukemia (RR-CLL) patients treated with venetoclax-rituximab (VEN-R). A retrospective analysis was performed to evaluate the efficacy and safety of VEN-R within the Polish Adult Leukemia Study Group (PALG) centers. The study group included 117 patients with RR-CLL (with early relapse after immunochemotherapy or bearing TP53 aberrations) treated with VEN-R in 2019-2023 outside clinical trials. Patients were treated with a median of 2 (range 1-9) previous lines of therapy. Twenty-two participants were previously treated with BTKi (18.8% out of 117). The median follow-up was 20.3 months (range 0.27-39.1). The overall response rate (ORR) was 95.3% in the group of patients in whom a response to treatment was assessed and 86.3% for all patients. Twenty patients (17.1% out of 117) achieved a complete response (CR), 81 (69.2%) achieved a partial response (PR), and in 5 patients (4.3%), disease progression was noted (assessed as the best response during treatment). The median PFS in the whole cohort was 36.97 (95% CI 24.5, not reached) months, and the median OS was not reached (95% CI 27.03, not reached). Thirty-six patients died during the follow-up, 10 (8.5%; 27.8% of deaths) due to COVID-19 infection. All grade neutropenia (n = 87/117, 74.4%; grade 3 or higher n = 67/117, 57.3%) was the most common treatment adverse event. Forty-five patients (38.5%) remained on treatment, and twenty-two (18.8%) completed 24 months of therapy, while it was discontinued in fifty cases (42.7%). In this real-world setting of early access in very high-risk RR-CLL patients, the VEN-R regimen was associated with shorter median PFS compared with the results of the MURANO trial. This outcome, however, could be attributed to patients' exposure to SARS-CoV-2 infection and the aggressive course of the disease as very high-risk patients, after multiple lines of prior therapies, were included in the Polish Ministry of Health reimbursement program.

Impaired adaptive immune response in COVID-19 convalescent patients with hematological malignancies.

OBJECTIVES: The immune dysregulation during SARS-CoV-2 has the potential to worsen immune homeostasis after recovery. Patients with hematological malignancies with COVID-19 have changes both in the innate and adaptive immune responses. Little is known about the severity of immune dysfunction following recovery from COVID-19 in hematological patients. METHODS: Here, we performed a comprehensive analysis of the lymphocyte subsets in peripheral blood mononuclear cells by FACS Canto II in 55 patients, including 42 with hematological malignancies 4-6 weeks after COVID-19. RESULTS: Hematological COVID-19 convalescents had deep reduction in CD3+ T cells, including helper T cells (CD3 + CD4+), naïve helper T cells (CD3 + CD4 + CD45RA+), and memory CD4+ T cells among with extremely low levels of Treg cells and decreased expression of both TCRα/ß and TCRγ/δ. Severe immune dysregulation in hematological convalescents was expressed by increased activation of T lymphocytes, both as elevated levels of activated T cells (CD3 + HLA-DR+) and activated cytotoxic T cells (CD3 + CD8 + HLA-DR+). CONCLUSIONS: Our findings showed a profound impairment of the adaptive immune response in hematological convalescents which might be a result of persistent activation of T cells. Convalescents with lymphoid malignancies showed more pronounced depletion of key T lymphocytes subpopulations in creating an effective adaptive response and immune memory.

Richter transformation - retrospective treatment outcomes analysis in Polish Adult Leukemia Study Group.

Richter transformation (RT) is defined as developing an aggressive lymphoma in 2-10% of patients suffering from chronic lymphocytic leukemia (CLL). So far, no complex analysis of RT demographics and treatment outcomes has been performed in Poland. Thus, the retrospective analysis of 124 patients with RT from Polish hematology centers was designed. Ninety-nine patients with diffuse large B-cell lymphoma (DLBCL-RT) were identified. The median overall survival (OS) for DLBCL-RT was 17.3 months, while for Hodgkin lymphoma (HL-RT)-21.3 months. In multivariate analysis, the independent factors of worse OS for DLBCL-RT were: prior CLL therapy, ECOG stage ≥2, and elevated serum LDH activity. Patients who proceeded to hematopoietic stem cell transplantation (HSCT) achieved better results. The median OS in allogeneic HSCT recipients was not reached, while in autologous HSCT median OS was 51.3 months. In conclusion, our study represents the largest dataset of patients diagnosed with RT in Poland and confirms its dismal prognosis.

Analysing COVID-19 treatment outcomes in dedicated wards at a large university hospital in northern Poland: a result-based observational study.

OBJECTIVES: Presenting outcomes of patients hospitalised for COVID-19 should be put in context and comparison with other facilities. However, varied methodology applied in published studies can impede or even hinder a reliable comparison. The aim of this study is to share our experience in pandemic management and highlight previously under-reported factors affecting mortality. We present outcomes of COVID-19 treatment in our facility that will allow for an intercentre comparison. We use simple statistical parameters-case fatality ratio (CFR) and length of stay (LOS). SETTING: Large clinical hospital in northern Poland serving over 120 000 patients annually. PARTICIPANTS: Data were collected from patients hospitalised in COVID-19 general and intensive care unit (ICU) isolation wards from November 2020 to June 2021. The sample consisted of 640 patients-250 (39.1 %) were women and 390 (60.9 %) were men, with a median age of 69 (IQR 59-78) years. RESULTS: Values of LOS and CFR were calculated and analysed. Overall CFR for the analysed period was 24.8%, varying from 15.9 % during second quarter 2021 to 34.1% during fourth quarter 2020. The CFR was 23.2% in the general ward and 70.7% in the ICU. All ICU patients required intubation and mechanical ventilation, and 44 (75.9 %) of them developed acute respiratory distress syndrome. The average LOS was 12.6 (±7.5) days. CONCLUSIONS: We highlighted the importance of some of the under-reported factors affecting CFR, LOS and thus, mortality. For further multicentre analysis, we recommend broad analysis of factors affecting mortality in COVID-19 using simple and transparent statistical and clinical parameters.

The Acquisition of Complement-Dependent Cytotoxicity by the Type II Anti-CD20 Therapeutic Antibody Obinutuzumab.

Rituximab, a prototypic anti-CD20 mAb, and the third-generation anti-CD20 mAb obinutuzumab differ in their ability to activate the complement system. According to recent studies, this contrast stems from the architecture of the antigen-antibody complex formed by these two mAbs that facilitates (rituximab) or disables (obinutuzumab) further oligomerization, leading to engagement of the initial classical complement pathway component C1q. We examined whether a gain-of-function C2 variant that acts downstream of C1q and enforces the formation of complement convertase resistant to physiological decay can impact complement activation by obinutuzumab. Co-application of the C2 variant with obinutuzumab and human serum resulted in complement-dependent cytotoxicity equal to or higher than attainable for rituximab. This effect was observed either in serum or hirudin-anticoagulated whole blood. Long-term (24 h) overall cytotoxicity of obinutuzumab was improved in target cells of moderate sensitivity to complement but diminished in cells of low sensitivity. Our results demonstrate that the ability of complement activation of a given antibody is not ultimately determined at the stage of initial interactions with its target antigen but is modulable at later stages of the cascade and that the benefit of the acquisition of this new effector mechanism by obinutuzumab depends on the target cell characteristics.

Secondary Oral Cancer after Systemic Treatment of Hematological Malignancies and Oral GVHD: A Systematic Review.

(1) Purpose: In this article, the authors decided to systematically review the available literature to identify potential correlations regarding secondary oral carcinoma occurring after hematological systemic treatment and oral chronic graft-versus-host disease. (2) Methods: Medline (PubMed) and Scopus (Elsevier) databases were searched, including articles from the years 2002-2022. The 33 unique results were assessed by a PRISMA flowchart, and we rejected 24 papers and included 9 articles in the review. (3) Results: The majority of patients suffered from the oral form of chronic graft-versus-host disease before the diagnosis of oral malignancy. Two common cancer sites were the tongue and buccal mucosa. The exact percentage of secondary oral carcinoma after hematopoietic stem cell transplantation could not be estimated due to a lack of data. (4) Conclusions: Every physician taking part in the follow-up of patients after hematological treatment should be aware of the possibility of secondary neoplastic disease in the oral cavity, especially in patients with oral graft-versus-host disease. Proper follow-up protocols and monitoring are needed in this patient group as the cause of these cancers appears to be multifactorial.

Bone marrow donation in Poland: 2021 update, and the impact of the coronavirus disease 2019 pandemic on haematopoietic stem cell transplantation.

Haematopoietic stem cell transplantation is a treatment modality that saves the health and lives of a growing number of patients around the world. In the majority of cases, the procedure is conducted to treat haematologic neoplasms, although it can also be used as a therapy for some non-haematooncological diseases. The progress that has been taking place in the field of haematopoietic stem cell transplantation involves the need for recruiting more and more potential unrelated bone marrow donors for allotransplantation. In Poland, the number of people registering as potential bone marrow donors has been continuously growing and in order to maintain this trend, it is necessary, above all, to consistently spread the noble idea of bone marrow donation and to raise Poles' awareness and knowledge about haematopoietic stem cell transplantation. Unfortunately, the situation caused by the severe acute respiratory syndrome coronavirus 2 pandemic limited the opportunities to act in public space and, as a consequence, it has become more difficult to achieve the objectives associated with recruiting new potential donors. The article provides a presentation of ethical and practical aspects associated with bone marrow donations as well as an overview of the legal situation concerning bone marrow donating and transplantation in Poland. The purpose of the paper is to also present some of the changes in transplantation procedures that have emerged as a consequence of the current epidemiological situation. The authors would like to emphasize the importance and the rightfulness of taking action that enables further development of transplantology.

In Silico Designed Gain-of-Function Variants of Complement C2 Support Cytocidal Activity of Anticancer Monoclonal Antibodies.

The molecular target for the classical complement pathway (CP) is defined by surface-bound immunoglobulins. Therefore, numerous anticancer monoclonal antibodies (mAbs) exploit the CP as their effector mechanism. Conversely, the alternative complement pathway (AP) is spontaneously induced on the host and microbial surfaces, but complement inhibitors on host cells prevent its downstream processing. Gain-of-function (GoF) mutations in the AP components that oppose physiological regulation directly predispose carriers to autoimmune/inflammatory diseases. Based on the homology between AP and CP components, we modified the CP component C2 so that it emulates the known pathogenic mutations in the AP component, factor B. By using tumor cell lines and patient-derived leukemic cells along with a set of clinically approved immunotherapeutics, we showed that the supplementation of serum with recombinant GoF C2 variants not only enhances the cytocidal effect of type I anti-CD20 mAbs rituximab and ofatumumab, but also lowers the threshold of mAbs necessary for the efficient lysis of tumor cells and efficiently exploits the leftovers of the drug accumulated in patients' sera after the previous infusion. Moreover, we demonstrate that GoF C2 acts in concert with other therapeutic mAbs, such as type II anti-CD20, anti-CD22, and anti-CD38 specimens, for overcoming cancer cells resistance to complement attack.

Outcome of SARS-CoV-2-Infected Polish Patients with Chronic Lymphocytic Leukemia.

BACKGROUND: The severe acute respiratory syndrome coronavirus (SARS-CoV-2) has become the cause of a worldwide pandemic, and its clinical infection course in patients with hematological malignancies may be severe. METHODS: We performed a retrospective study on 188 chronic lymphocytic leukemia patients (CLL) with COVID-19 infection. RESULTS: At the time of infection 51 patients (27.1%) were treated with Bruton tyrosine kinase inhibitor (BTKi), 46 (24.5%) with anti-CD20 antibodies while 37 patients (19.7%) received venetoclax. In total, 111 patients (59.0%) required hospitalization and 50 patients (26.5%) died due to COVID-19. Patients with poor performance status (ECOG >1; p = 0.02), advanced age (>65 years; p = 0.04), low hemoglobin concentration (≤10 g/dl; p = 0.0001), low platelets (<100 × 109/L; p = 0.003), and elevated lactate dehydrogenase level (LDH; p = 0.014) had an increased risk of death due to COVID-19. Neither CLL treatment status (treatment naïve vs. treated) nor the type of CLL-directed treatment had impact on the SARS-CoV-2 related risk of death. The multivariate survival analysis showed that advanced age (p = 0.009) and low platelet count (p = 0.0001) were associated with significantly shorter patients' overall survival. CONCLUSIONS: SARS-CoV-2 infection in CLL patients is associated with poor outcome regardless of administered CLL-directed treatment.

Monitoring of the Complement System Status in Patients With B-Cell Malignancies Treated With Rituximab.

Rituximab is a pioneering anti-CD20 monoclonal antibody that became the first-line drug used in immunotherapy of B-cell malignancies over the last twenty years. Rituximab activates the complement system in vitro, but there is an ongoing debate on the exact role of this effector mechanism in therapeutic effect. Results of both in vitro and in vivo studies are model-dependent and preclude clear clinical conclusions. Additional confounding factors like complement inhibition by tumor cells, loss of target antigen and complement depletion due to excessively applied immunotherapeutics, intrapersonal variability in the concentration of main complement components and differences in tumor burden all suggest that a personalized approach is the best strategy for optimization of rituximab dosage and therapeutic schedule. Herein we critically review the existing knowledge in support of such concept and present original data on markers of complement activation, complement consumption, and rituximab accumulation in plasma of patients with chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphomas (NHL). The increase of markers such as C4d and terminal complement complex (TCC) suggest the strongest complement activation after the first administration of rituximab, but not indicative of clinical outcome in patients receiving rituximab in combination with chemotherapy. Both ELISA and complement-dependent cytotoxicity (CDC) functional assay showed that a substantial number of patients accumulate rituximab to the extent that consecutive infusions do not improve the cytotoxic capacity of their sera. Our data suggest that individual assessment of CDC activity and rituximab concentration in plasma may support clinicians' decisions on further drug infusions, or instead prescribing a therapy with anti-CD20 antibodies like obinutuzumab that more efficiently activate effector mechanisms other than complement.