The complement C5 inhibitor crovalimab in paroxysmal nocturnal hemoglobinuria.

Complement C5 inhibition is the standard of care (SoC) for patients with paroxysmal nocturnal hemoglobinuria (PNH) with significant clinical symptoms. Constant and complete suppression of the terminal complement pathway and the high serum concentration of C5 pose challenges to drug development that result in IV-only treatment options. Crovalimab, a sequential monoclonal antibody recycling technology antibody was engineered for extended self-administered subcutaneous dosing of small volumes in diseases amenable for C5 inhibition. A 3-part open-label adaptive phase 1/2 trial was conducted to assess safety, pharmacokinetics, pharmacodynamics, and exploratory efficacy in healthy volunteers (part 1), as well as in complement blockade-naive (part 2) and C5 inhibitor-treated (part 3) PNH patients. Twenty-nine patients were included in part 2 (n = 10) and part 3 (n = 19). Crovalimab concentrations exceeded the prespecified 100-µg/mL level and resulted in complete and sustained terminal complement pathway inhibition in treatment-naive and C5 inhibitor-pretreated PNH patients. Hemolytic activity and free C5 levels were suppressed below clinically relevant thresholds (liposome assay <10 U/mL and <50 ng/mL, respectively). Safety was consistent with the known profile of C5 inhibition. As expected, formation of drug-target-drug complexes was observed in all 19 patients switching to crovalimab, manifesting as transient mild or moderate vasculitic skin reactions in 2 of 19 participants. Both events resolved under continued treatment with crovalimab. Subcutaneous crovalimab (680 mg; 4 mL), administered once every 4 weeks, provides complete and sustained terminal complement pathway inhibition in patients with PNH, warranting further clinical development (ClinicalTrials.gov identifier, NCT03157635).

[Molecular monitoring of myeloid leukemia]. / A krónikus mieloid leukémia molekuláris monitorozásának aktuális kérdései.

The last fifteen years brought a revolution both in treatment and diagnostics of chronic myeloid leukemia. Nowadays, the main method for monitoring of the disease is molecular monitoring with real-time PCR technology which can indicate treatment modification. With the development of the international scale and inter-laboratory standardization the residual tumor mass can be measured accurately and the results are comparable between the different laboratories. By the growing experience in the field of molecular responses we can now accurately predict treatment outcome early on with the so called early molecular response and BCR-ABL1 kinetics, allowing the selection of the best TKI with the treatment-free remission representing real option of the near future. Nevertheless, further advancements can be expected, including the workflow automatization and detection of even deeper molecular responses.

[Novelties and experience with tyrosine kinase inhibitor therapy in chronic myeloid leukemia]. / Újdonságok és tapasztalatok a krónikus mieloid leukémia tirozinkináz-gátló kezelésében.

The introduction of tyrosine kinase inhibitor (TKI) treatment has resulted in dramatically improved survival in chronic myeloid leukemia (CML). With the new generation of TKIs the majority of patients reach optimal molecular response. Due to the improving survival and the need for lifelong treatment, the safety profile of the various TKIs and the comorbidities of patients have to be considered. More than half of our CML patients had comorbidities that could have influenced the choice of therapy. Because of the high prevalence of cardiovascular comorbidities, cardiovascular risk assessment plays an important role in the care of CML patients. The aim of this article is to summarize the current national and international guidelines of the treatment in CML and to show the importance of comorbidities and cardiovascular risk assessment in our CML patients.

Beneficial Effect of Lenalidomide-Dexamethason Treatment in Relapsed/Refractory Multiple Myeloma Patients: Results of Real-Life Data From 11 Hungarian Centers.

In Hungary, the cost of lenalidomide-based therapy is covered only for relapsed multiple myeloma (MM) patients, therefore lenalidomide is typically used in the second-line either as part of a triplet with proteasome inhibitors or as a doublet. Lenalidomide-dexamethasone is a standard treatment approach for relapsed/refractory MM, and according to recent large randomized clinical trials (RCT, the standard arm of POLLUX, ASPIRE, TOURMALINE), the progression-free survival (PFS) is expected to be approximately 18 months. We surveyed ten Hungarian centers treating MM and collected data of 278 patients treated predominantly after 2016. The median age was 65 years, and patients were distributed roughly equally over the 3 international staging system groups, but patients with high risk cytogenetics were underrepresented. 15.8% of the patients reached complete response, 21.6% very good partial response, 40.6% partial response, 10.8% stable disease, and 2.5% progressed on treatment. The median PFS was unexpectedly long, 24 months, however only 9 months in those with high risk cytogenetics. We found interesting differences between centers regarding corticosteroid type (prednisolone, methylprednisolone or dexamethasone) and dosing, and also regarding the choice of anticoagulation, but the outcome of the various centers were not different. Although the higher equivalent steroid dose resulted in more complete responses, the median PFS of those having lower corticosteroid dose and methylprednisolone were not inferior compared to the ones with higher dose dexamethasone. On multivariate analysis high risk cytogenetics and the number of prior lines remained significant independent prognostic factors regarding PFS (p < 0.001 and p = 0.005). Our results show that in well-selected patients Lenalidomide-dexamethasone can be a very effective treatment with real-world results that may even outperform those reported in the recent RCTs. This real world information may be more valuable than outdated RCT data when treatment options are discussed with patients.

Calreticulin mutation specific CAL2 immunohistochemistry accurately identifies rare calreticulin mutations in myeloproliferative neoplasms.

Mutations of the multifunctional protein calreticulin (CALR) are recognised as one of the main driver alterations involved in the pathogenesis of Philadelphia negative myeloproliferative neoplasms (Ph- MPN) and also represent a major diagnostic criterion in the most recent World Health Organization classification of myeloid neoplasms. Nowadays, quantitative assessment of the driver mutations is gaining importance, as recent studies demonstrated the clinical relevance of the mutation load reflecting the size of the mutant clone. Here, we performed for the first time a manual and automated quantitative assessment of the CALR mutation load at protein level using CAL2, a recently developed CALR mutation specific monoclonal antibody, on a cohort of 117 patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF) and compared the CALR protein mutation loads with the CALR mutation load values established by a molecular assay. Eighteen different CALR mutations were detected in the cohort of the 91 CALR mutant cases. Mutation loads of the CALR mutations were between 13% and 94% with mean value in PMF cases significantly higher than ET cases (49.94 vs 41.09; t-test, p=0.004). Cases without CALR mutation (n=26) showed no or only minimal labelling with the CAL2 antibody, while all 18 different types of CALR mutations were associated with CAL2 labelling. The CALR mutation load showed a significant correlation (p=0.03) with the occurrence of major thrombotic events, with higher mutation load in patients presenting with these complications. We report a 100% concordance between the mutation status determined by immunohistochemistry and the CALR molecular assay, and we extend the applicability of this approach to 16 rare CALR mutations previously not analysed at protein level.