Advancing therapeutic complement inhibition in hematologic diseases: PNH and beyond.

Complement is an elaborate system of innate immunity. Genetic variants and autoantibodies leading to excessive complement activation are implicated in a variety of human diseases. Among them, the hematologic disease paroxysmal nocturnal hemoglobinuria (PNH) remains the prototypic model of complement activation and inhibition. Eculizumab, the first-in-class complement inhibitor, was approved for PNH in 2007. Addressing some of the unmet needs, a long-acting C5 inhibitor, ravulizumab, and a C3 inhibitor, pegcetacoplan, have also now been approved for PNH. Novel agents, such as factor B and factor D inhibitors, are under study, with very promising results. In this era of several approved targeted complement therapeutics, selection of the proper drug must be based on a personalized approach. Beyond PNH, complement inhibition has also shown efficacy and safety in cold agglutinin disease, primarily with the C1s inhibitor of the classical complement pathway sutimlimab, as well as with pegcetacoplan. Furthermore, C5 inhibition with eculizumab and ravulizumab, as well as inhibition of the lectin pathway with narsoplimab, is being investigated in transplantation-associated thrombotic microangiopathy. With this revolution of next-generation complement therapeutics, additional hematologic entities, such as delayed hemolytic transfusion reaction or immune thrombocytopenia, might also benefit from complement inhibitors. Therefore, this review aims to describe state-of-the-art knowledge of targeting complement in hematologic diseases, focusing on (1) complement biology for the clinician, (2) complement activation and therapeutic inhibition in prototypic complement-mediated hematologic diseases, (3) hematologic entities under investigation for complement inhibition, and (4) other complement-related disorders of potential interest to hematologists.

Clinical Efficacy of Isatuximab Plus Carfilzomib and Dexamethasone in Relapsed/Refractory Multiple Myeloma Patients.

Isatuximab, a novel anti-CD38 monoclonal antibody, is approved in combination with carfilzomib and dexamethasone (Isa-Kd) in relapsed/refractory multiple myeloma (RRMM) patients. Because of its recent introduction, real-world efficacy and safety are poorly reported. In this Italian multicenter real-life observational retrospective study, efficacy and safety of the Isa-Kd regimen were evaluated in a cohort of 103 RRMM patients. Overall response rate (ORR) was 85%, with stringent (sCR) or complete response (CR) in 18% of cases and very good partial response (VGPR) in 39%. Median PFS and OS were not reached within the study period, while 1-year PFS and OS were 72% and 77%, respectively. Hematological toxicities were observed in 42% of subjects, and cardiac toxicities occurred in 24% of cases. Moreover, we conducted a subanalysis on patients (N = 69) treated with Isa-Kd after one prior line of therapy, showing an ORR of 88%, with sCR + CR in 20% of subjects, VGPR in 46%, and PR in 22% of patients. In this group, median PFS and OS were not reached, while 1-year PFS and OS were 92% and 95%, respectively. In conclusions, our study confirmed Isa-Kd as an effective treatment option for RRMM with a manageable safety profile even in real-life settings.

Towards a personalized preventive strategy of Herpes zoster infection in patients with hematologic diseases or hematopoietic stem cell transplant recipients: a position paper from an ad hoc Italian expert panel.

The identification of patients at high risk of herpes zoster (HZ) requiring a prevention strategy with antiviral prophylaxis and anti-HZ vaccine is a clinically relevant issue in patients with immunological impairment. Absence of trials comparing vaccination to pharmacological prophylaxis or defining their sequential use makes the optimal prevention strategy uncertain. This article presents the results of group discussion among an ad hoc constituted panel of experts aimed to review the literature regarding antiviral prophylaxis and vaccine efficacy and safety in populations with malignant and non-malignant hematological diseases, and submitted to hematopoietic stem cell transplantation. The panel used the consensus methodology and proposed solutions for prevention strategy producing advice for the management of the most relevant unmet clinical needs. Such a comprehensive overview aims to support at the practice of HZ pharmacological and vaccine prevention and informing the design and the need of implementation of new studies in the field.

How we('ll) treat paroxysmal nocturnal haemoglobinuria: diving into the future.

Paroxysmal nocturnal haemoglobinuria (PNH) is characterized by complement-mediated intravascular haemolysis, severe thrombophilia and bone marrow failure. While for patients with bone marrow failure the treatment follows that of immune-mediated aplastic anaemia, that of classic, haemolytic PNH is based on anti-complement medication. The anti-C5 monoclonal antibody eculizumab has revolutionized treatment, resulting in control of intravascular haemolysis and thromboembolic risk, with improved long-term survival. Novel strategies of complement inhibition are emerging. New anti-C5 agents reproduce the safety and efficacy of eculizumab, with improved patient convenience. Proximal complement inhibitors have been developed to address C3-mediated extra-vascular haemolysis and seem to improve haematological response.

Bone Marrow of Contention: A Rare Case of Recurrent Acute Hepatitis.

Hepatitis-associated aplastic anemia is a well-recognized clinical syndrome in which marrow failure follows the development of hepatitis. Although aplastic anemia is intimately related to paroxysmal nocturnal hemoglobinuria, until now, no cases of PNH-associated hepatitis have been described. We report a case of recurrent acute hepatitis preceding the clinical onset of PNH. Treatment of PNH with the complement inhibitor eculizumab (Soliris®) prevented both recurrences of episodes of intravascular hemolysis and liver enzyme alteration. This is the first known published case of PNH-associated hepatitis.

Outcome of Allogeneic Hematopoietic Stem Cell Transplantation in Adult Patients with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia in the Era of Tyrosine Kinase Inhibitors: A Registry-Based Study of the Italian Blood and Marrow Transplantation Society (GITMO).

We performed a nationwide registry-based analysis to describe the clinical outcome of adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) who underwent an allogeneic hematopoietic stem cell transplantation (HSCT) after a tyrosine kinase inhibitor (TKI)-based treatment A total of 441 patients were included in the study. The median age at HSCT was 44 years (range, 18 to 70 years). All 441 patients (100%) received TKI before HSCT (performed between 2005 and 2016). Of these 441 patients, 404 (92%) were in cytologic complete remission (CR), whereas the remaining 37 (8%) had active disease at the time of HSCT. Molecular minimal residual disease (MRD) was negative in 147 patients (36%) at the time of HSCT. The donor was unrelated in 46% of patients. The most prevalent source of stem cells was peripheral blood (70%). The conditioning regimen was myeloablative in 82% of cases (total body irradiation-based in 50%) and included antithymocyte globulin in 51% of patients. With a median follow-up after HSCT of 39.4 months (range, 1 to 145 months), the probability of overall survival (OS) at 1, 2, and 5 years was 69.6%, 61.1% and 50.3%, respectively, with a median OS of 62 months. Progression-free survival (PFS) at 1, 2, and 5 years was 60.2%, 52.1% and 43.7%, respectively. OS and PFS were significantly better in patients who were in CR and MRD-negative at the time of HSCT compared with patients who were in CR but MRD-positive (50% OS not reached versus 36 months; P = .015; 50% PFS not reached versus 26 months, P = .003). The subgroup of MRD-negative patients both at HSCT and at 3 months after HSCT had a better outcome (5-year OS, 70%). Conversely, the 37 patients who underwent a HSCT with active Ph+ ALL had a median OS of 7 months and a median PFS of 5 months. The 5-year cumulative incidence of relapse was significantly lower in MRD-negative patients (19.5% versus 35.4%; P = .001). Nonrelapse mortality (NRM) after 1, 2, and 5 years was 19.1% (95% confidence interval [CI], 15.5% to 22.9%), 20.7% (95% CI, 17% to 24.7%), and 24.1% (95% CI, 20% to 28.5%), respectively. NRM was significantly lower with a modified European Society for Blood and Marrow Transplantation (mEBMT) risk score of 0 to 2 compared with ≥3 (15% versus 25%; P = .016). The median OS for Ph+ ALL patients who underwent a TKI-based treatment followed by an allogeneic HSCT, in recent years at the GITMO centers, was 62 months. Evaluation of the mEBMT risk score can be useful to predict NRM. Our data confirm that HSCT is a potentially curative treatment for Ph+ ALL with an excellent outcome for the subgroup of MRD-negative patients both at HSCT and at 3 months after HSCT (5-year OS, 70%).

Small-molecule factor D inhibitors targeting the alternative complement pathway.

Complement is a key component of the innate immune system, recognizing pathogens and promoting their elimination. Complement component 3 (C3) is the central component of the system. Activation of C3 can be initiated by three distinct routes-the classical, the lectin and the alternative pathways-with the alternative pathway also acting as an amplification loop for the other two pathways. The protease factor D (FD) is essential for this amplification process, which, when dysregulated, predisposes individuals to diverse disorders including age-related macular degeneration and paroxysmal nocturnal hemoglobinuria (PNH). Here we describe the identification of potent and selective small-molecule inhibitors of FD. These inhibitors efficiently block alternative pathway (AP) activation and prevent both C3 deposition onto, and lysis of, PNH erythrocytes. Their oral administration inhibited lipopolysaccharide-induced AP activation in FD-humanized mice. These data demonstrate the feasibility of inhibiting the AP with small-molecule antagonists and support the development of FD inhibitors for the treatment of complement-mediated diseases.

Incidence and outcome of invasive fungal diseases after allogeneic stem cell transplantation: a prospective study of the Gruppo Italiano Trapianto Midollo Osseo (GITMO).

Epidemiologic investigation of invasive fungal diseases (IFDs) in allogeneic hematopoietic stem cell transplantation (allo-HSCT) may be useful to identify subpopulations who might benefit from targeted treatment strategies. The Gruppo Italiano Trapianto Midollo Osseo (GITMO) prospectively registered data on 1858 consecutive patients undergoing allo-HSCT between 2008 and 2010. Logistic regression analysis was performed to identify risk factors for proven/probable IFD (PP-IFD) during the early (days 0 to 40), late (days 41 to 100), and very late (days 101 to 365) phases after allo-HSCT and to evaluate the impact of PP-IFDs on 1-year overall survival. The cumulative incidence of PP-IFDs was 5.1% at 40 days, 6.7% at 100 days, and 8.8% at 12 months post-transplantation. Multivariate analysis identified the following variables as associated with PP-IFDs: transplant from an unrelated volunteer donor or cord blood, active acute leukemia at the time of transplantation, and an IFD before transplantation in the early phase; transplant from an unrelated volunteer donor or cord blood and grade II-IV acute graft-versus-host disease (GVHD) in the late phase; and grade II-IV acute GVHD and extensive chronic GVHD in the very late phase. The risk for PP-IFD was significantly higher when acute GVHD was followed by chronic GVHD and when acute GVHD occurred in patients undergoing transplantation with grafts from other than matched related donors. The presence of PP-IFD was an independent factor in long-term survival (hazard ratio, 2.90; 95% confidence interval, 2.32 to 3.62; P < .0001). Our findings indicate that tailored prevention strategies may be useful in subpopulations at differing levels of risk for PP-IFDs.

Outcome of aplastic anemia in adolescence: a survey of the Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation.

We analyzed the outcome of 537 adolescents (age 12-18 years) with idiopathic aplastic anemia included in the database of the Severe Aplastic Anemia Working Party of the European Group for Blood and Marrow Transplantation comparing: i) matched family donor hematopoietic stem cell transplantation performed as first-line treatment with ii) front-line immunosuppressive therapy not followed by subsequent transplant given for failure and with iii) hematopoietic stem cell transplantation performed after failed front-line immunosuppressive therapy. Overall survival was 86% in the matched family donor hematopoietic stem cell transplantation group, 90% in patients given front-line immunosuppressive alone (those who did not fail this treatment and who did not receive subsequent rescue with hematopoietic stem cell transplantation) and 78% in subjects who underwent hematopoietic stem cell transplantation post failed front-line immunosuppressive therapy (P=0.14). Event-free survival in the same groups was respectively 83%, 64% and 71% (P=0.04). Cumulative incidence of rejection was 8% in matched family donor hematopoietic stem cell transplantation and 9% in transplants post failed front-line immunosuppression (P=0.62). Cumulative incidence of acute graft-versus-host disease was 12% in matched family donor transplants and 18% in transplants post failed immunosuppression (P=0.18). Chronic graft-versus-host disease was higher in matched family donor hematopoietic stem cell transplantation (8%) than in transplants post failed immunosuppressive therapy (20%) (P=0.0009). Cumulative incidence of post-therapy malignancies was 0.7% in matched family donor transplantations, 7% in transplantations post failed immunosuppression and 21% after front-line immunosuppression (P=0.0017). In the whole cohort, under multivariate analysis, the diagnosis to treatment interval of two months or under positively affected overall survival whereas up-front immunosuppression alone (with no subsequent rescue transplants) negatively affected event-free survival. In transplanted patients an interval from diagnosis to treatment of 2 months or under, bone marrow as source of cells and first-line matched family donor transplants provided a significant advantage in overall and event-free survival. Aplastic anemia in adolescents has a very good outcome. If a matched family donor is available, hematopoietic stem cell transplantation using bone marrow cells is the first choice treatment. If such a donor is not available, immunosuppressive treatment may still be an acceptable second choice, also because, in case of failure, hematopoietic stem cell transplantation is a very good rescue option.

Limited efficacy of 3 + 7 plus gemtuzumab ozogamycin in newly diagnosed fit intermediate genetic risk acute myeloid leukemia patients.

BACKGROUND: Gemtuzumab-ozogamycin (GO) is approved in combination with high-dose chemotherapy for treatment-naïve low- and intermediate-risk acute myeloid leukemia (AML). AIMS: In this retrospective real-life multicenter study, we reported efficacy and safety of GO plus high-dose chemotherapy in newly diagnosed AML patients. METHODS AND RESULTS: A total of 31 fit low- and intermediate-risk AML patients treated with GO-based regimens were retrospectively included in this real-life multicenter study, and results were compared with a control cohort treated with 3 + 7 alone. Complete remission (CR) rate after induction was 77%, and most responders (45%) underwent two GO-based consolidation, and minimal residual disease (MRD) negativity was observed in 17 cases (55%) after the end of consolidation. Low genetic risk was associated with increased CR rate compared with intermediate-risk AML (88% vs. 33%; p < .001), as well as prolonged overall survival (OS; hazard ratio, 0.16; 95% confidential interval, 0.02-0.89; p < .001). GO addition resulted in a survival benefit for low-risk AML (median OS not reached vs. 25 months; p = .19) while not for intermediate-risk subjects (10 vs. 13 months; p = .92), compared with the control group. Moreover, GO-treated patients experienced fever of unknown origin or sepsis in 42% or 36% of cases, respectively, with one death during induction due to septic shock, with similar rates compared with the control group (p = .3480 and p = .5297, respectively). No cases of veno-occlusive disease after allogeneic transplantation were observed. CONCLUSIONS: Our real-life multicenter study confirmed GO-based treatment efficacy with high MRD negativity rates in fit newly diagnosed AML patients, especially in those with low genetic risk and core binding factor, while limited benefits were observed in intermediate-risk AML. However, further validation on larger prospective cohorts is required.

Post-Transplant Cyclophosphamide versus Anti-Thymocyte Globulin in Patients with Hematological Malignancies Treated with Allogeneic Hematopoietic Stem Cell Transplantation from Haploidentical and Matched Unrelated Donors: A Real-Life Experience.

Background: Post-transplant cyclophosphamide (PTCY) is widely used as graft versus host disease (GvHD) prophylaxis in allogeneic hematopoietic stem cell transplant (HSCT) recipients, with reported clinical benefits in patients who underwent transplant from a matched unrelated donor (MUD). However, real-life data on clinical efficacy and safety of PTCY in haploidentical and MUD transplantations are still poor. Methods: In our real-life retrospective observational study, we included a total of 40 consecutive adult patients who underwent haploidentical or MUD HSCT for various hematological malignancies and who received PTCY (n = 24) or ATG (n = 16) as GvHD prophylaxis at Hematology Units from hospitals of Salerno and Avellino, Italy, and clinical outcomes were compared. Results: We showed protective effects of PTCY against disease relapse with the relapse rate after transplantation of 16% versus 50% in the ATG arm (p = 0.02). All-cause mortality was lower (36% vs. 75%; p = 0.02) and the 2-year overall survival was slightly superior in patients administered PTCY (61% vs. 42%; p = 0.26). Conclusions: We support the use of PTCY, even in a real-life setting; however, the optimization of this protocol should be further investigated to better balance relapse prevention and GvHD prophylaxis.

Hemolytic paroxysmal nocturnal hemoglobinuria: 20 years of medical progress.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by intravascular hemolysis, thrombosis and bone marrow failure. Prior to the availability of specific therapy, PNH led to the death of around half of affected individuals, mainly through thrombotic complications, with a particular grim prognosis for patients presenting with classic PNH. The anti-C5 monoclonal antibody eculizumab has revolutionized treatment, controlling intravascular hemolysis and thrombosis occurrence, with improved long-term survival. However, eculizumab is infused on a lifelong 2 week basis and most of the patients are anemic, with some remaining transfusion-dependent. New anti-C5 agents reproduce the safety and efficacy of eculizumab, with improved patient convenience, while proximal complement inhibitors have been developed to address C3-mediated extravascular hemolysis, aiming to eventually improve hematological response. This review will describe the spectacular medical progress in PNH of the last 20 years, as well as the risks and benefits of a novel approach.

Dyskeratosis congenita and squamous cell carcinoma of the mandibular alveolar ridge.

Dyskeratosis congenita is a rare disease caused by telomerase dysfunction classically characterised by the triad: skin pigmentation, nail dystrophy and mucosal leukoplakia. Few cases are described in literature regarding patients with head and neck squamous cell carcinoma affected by dyskeratosis congenita, and the therapeutic decisions are not yet well defined. A review of the literature of the last 20 years (2001-2021) was performed, and it was analysed the case of a 38-year-old male patient affected by dyskeratosis congenita diagnosed with a squamous cell carcinoma of the inferior alveolar ridge, treated with surgery. The absence of complications and the good postoperative recovery of the patient comfort in saying that resection and reconstructive surgery can be safely performed. The occurrence of disseminated disease 6 months after the treatment warns about the extreme aggressiveness of the pathology, its often systemic nature and the necessity of a multidisciplinary approach as well as further studies.

Veno-occlusive Disease in HSCT Patients: Consensus-based Recommendations for Risk Assessment, Diagnosis, and Management by the GITMO Group.

Variation in clinical practice affects veno-occlusive disease management, mainly in patients who undergo allogeneic hematopoietic stem cell transplantation. Disputes about diagnostic criteria, treatment, and prophylaxis, due to the lack of high-quality data, are at the base of this variability. With the aim of limiting inconsistency in clinical care, thus improving both patient outcomes and data collection reliability, the Italian Society of Stem cell transplant (Gruppo Italiano Trapianto Midollo Osseo e Terapia Cellulare) launched a collaborative effort to formulate recommendations based on integration of available evidence and expert's consensus. A systematic method, according to US National Institute of Health guidelines and Italian National System for Guidelines, was used. Twenty-nine recommendations were approved with a strong (20) or weak (9) level of agreement, while 26 were rejected. In particular, the panel pointed out the need to achieve an early diagnosis, encouraging the adoption of European Society for Blood and Marrow Transplantation criteria and the prompt use of ultrasonography. Moreover, our experts strongly recommended in favor of prophylactic use of ursodeoxycholic acid. As soon as a veno-occlusive disease diagnosis is established, treatment with defibrotide should be started for at least 21 days. A number of areas of uncertainty, particularly concerning risk stratification and use of diagnostic tools such as elastography has been identified and discussed.

Alemtuzumab is safe and effective as immunosuppressive treatment for aplastic anaemia and single-lineage marrow failure: a pilot study and a survey from the EBMT WPSAA.

An alemtuzumab-based experimental immunosuppressive treatment (IST) regimen was investigated in 35 patients with severe aplastic anaemia (SAA), pure red cell (PRCA) or pure white cell aplasia (PWCA). Alemtuzumab total dose was 73-103 mg s.c., followed by cyclosporine. No serious toxicity due to the regimen was observed. Adverse events were clinically irrelevant; infectious events were rare. The total response rate was 58%, 84% and 100% in SAA, PRCA and PWCA, respectively, with corresponding 6 months cumulative response probabilities of 84%, 84% and 100%. Subcutaneous alemtuzumab is a feasible and sufficiently safe IST regimen for patients suffering from immune-mediated marrow failures.

Easy genotyping of complement C3 'slow' and 'fast' allotypes by tetra-primer amplification refractory mutation system PCR.

Complement C3 'slow' and 'fast' allotypes are associated with immune-mediated disorders and may affect the outcome of renal transplantation. We report a tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) that provides a rapid, reproducible and cost-effective method to genotype both complement C3 'slow' and 'fast' alleles by a single tube reaction.