Low-burden TP53 mutations represent frequent genetic events in CLL with an increased risk for treatment initiation.

TP53 aberrations predict chemoresistance and represent a contraindication for the use of standard chemoimmunotherapy in chronic lymphocytic leukaemia (CLL). Recent next-generation sequencing (NGS)-based studies have identified frequent low-burden TP53 mutations with variant allele frequencies below 10%, but the clinical impact of these low-burden TP53 mutations is still a matter of debate. In this study, we aimed to scrutinise the subclonal architecture and clinical impact of TP53 mutations using a sensitive, NGS-based mutation analysis in a 'real-world' cohort of 901 patients with CLL. In total, 225 TP53 mutations were identified in 17.5% (158/901) of the patients; 48% of these alterations represented high-burden mutations, while 52% were low-burden TP53 mutations. Low-burden mutations as sole alterations were identified in 39% (62/158) of all mutated cases with 82% (51/62) of these being represented by a single low-burden TP53 mutation. Patients harbouring low-burden TP53 mutations had significantly lower time to first treatment compared to patients with wild-type TP53. Our study has expanded the knowledge on the frequency, clonal architecture, and clinical impact of low-burden TP53 mutations. By demonstrating that patients with sole low-burden TP53 variants represent more than one-third of patients with TP53 mutations and have an increased risk for treatment initiation, our findings strengthen the need to redefine the threshold of TP53 variant reporting to below 10% in the routine diagnostic setting.

Landscape of BCL2 Resistance Mutations in a Real-World Cohort of Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia Treated with Venetoclax.

The oral, highly selective Bcl2 inhibitor venetoclax has substantially improved the therapeutic landscape of chronic lymphocytic leukemia (CLL). Despite the remarkable response rates in patients with relapsed/refractory (R/R) disease, acquired resistance is the leading cause of treatment failure, with somatic BCL2 mutations being the predominant genetic drivers underpinning venetoclax resistance. To assess the correlation between disease progression and the most common BCL2 mutations G101V and D103Y, sensitive (10-4) screening for the most common BCL2 mutations G101V and D103Y was performed in 67 R/R CLL patients during venetoclax single-agent or venetoclax-rituximab combination therapy. With a median follow-up time of 23 months, BCL2 G101V and D103Y were detected in 10.4% (7/67) and 11.9% (8/67) of the cases, respectively, with four patients harboring both resistance mutations. Ten out of eleven patients carrying BCL2 G101V and/or D103Y experienced relapse during the follow-up period, representing 43.5% of the cases (10/23) showing clinical signs of disease progression. All BCL2 G101V or D103Y variants were detected in patients receiving venetoclax as a continuous single-agent treatment while these mutations were not observed during or after fixed-duration venetoclax therapy. Targeted ultra-deep sequencing of BCL2 uncovered three additional variants in four patient samples obtained at relapse, suggesting convergent evolution and implying a cooperating role of BCL2 mutations in driving venetoclax resistance. This cohort is the largest R/R CLL patient population reported to date in which BCL2 resistance mutations were investigated. Our study demonstrates the feasibility and clinical value of sensitive screening for BCL2 resistance mutations in R/R CLL.

Revealing a Phenotypical Appearance of Ibrutinib Resistance in Patients With Chronic Lymphocytic Leukaemia by Flow Cytometry.

Background: Ibrutinib is widely known as an effective and well-tolerated therapeutical choice of the chronic lymphocytic leukaemia (CLL). However, acquired resistance may occur during the treatment, causing relapse. Early detection of ibrutinib resistance is an important issue, therefore we aimed to find phenotypic markers on CLL cells the expression of which may correlate with the appearance of ibrutinib resistance. Methods: We examined 28 patients' peripheral blood (PB) samples (treatment naïve, ibrutinib sensitive, clinically ibrutinib resistant). The surface markers' expression (CD27, CD69, CD86, CD184, CD185) were measured by flow cytometry. Furthermore, the BTKC481S resistance mutation was assessed by digital droplet PCR. Moreover, the CLL cells' phenotype of a patient with acquired ibrutinib resistance was observed during the ibrutinib treatment. Results: The expression of CD27 (p = 0.030) and CD86 (p = 0.031) became higher in the clinically resistant cohort than in the ibrutinib sensitive cohort. Besides, we found that high CD86 and CD27 expressions were accompanied by BTKC481S mutation. Our prospective study showed that the increase of the expression of CD27, CD69 and CD86 was noticed ahead of the clinical resistance with 3 months. Conclusion: Our study suggests that the changes of the expression of these markers could indicate ibrutinib resistance and the examination of these phenotypic changes may become a part of the patients' follow-up in the future.

Retrospective analysis of chronic myeloid leukemia patients treated in the Department of Internal Medicine and Oncology, Semmelweis University, between 2003 and 2019 / Krónikus myeloid leukaemia miatt 2003 és 2019 között a Semmelweis Egyetem Belgyógyászati és Onkológiai Klinikáján kezelt betegek adatainak elemzése

Összefoglaló. Bevezetés: A krónikus myeloid leukaemia a diagnosztika fejlodésének és a tirozin-kináz-gátlók bevezetésének köszönhetoen az elmúlt évtizedekben kiváló prognózisú betegséggé vált. Célkituzés: A betegséggel kapcsolatos ismereteink nagy része klinikai vizsgálatokból származik, emiatt kiemelt szerepük van a nem szelektált beteganyagon végzett elemzéseknek. Módszer: Retrospektív elemzésünkben a Semmelweis Egyetem Belgyógyászati és Onkológiai Klinikáján 2003 és 2019 között tirozin-kináz-gátló kezelésben részesült betegek adatait tekintettük át. Eredmények: Klinikánkon összesen 88 beteg részesült terápiában, közülük 73 beteg az analízis idopontjában is kezelés alatt állt. A betegek 5 éves össztúlélése 86%, 5 éves progressziómentes túlélése 70% volt. 9 beteg halt meg, közülük 2 betegnél a halál oka a progrediáló alapbetegség volt. 38 betegnél volt szükség az elso vonalban terápiaváltásra, a váltás oka akkor elsosorban az elégtelen terápiás válasz volt. A késobbi terápiaváltásokra elsosorban intolerancia miatt került sor. Az elso vonalban a betegek több mint fele major molekuláris választ ért el, a jelenlegi kezelés mellett a betegek 85%-ánál major molekuláris választ detektáltunk. Megbeszélés: Adataink alapján az intézményünkben kezelt betegek túlélése és a betegek által elért terápiás válasz megfelel a nemzetközi adatoknak. Következtetés: Mivel nem válogatott beteganyagról van szó, a kapott eredmények pontosabb képet adhatnak a krónikus myeloid leukaemia tirozin-kináz-gátlóval történt kezelésének eredményeirol. Orv Hetil. 2021; 162(32): 1297-1302. INTRODUCTION: As a result of advances in diagnostic techniques and the introduction of tyrosine kinase inhibitors, the prognosis of chronic myeloid leukemia has improved over the last decades. OBJECTIVE: Most of our knowledge about chronic myeloid leukemia results from clinical trials, therefore data derived from non-selected patient population is substantial. METHOD: Data of chronic myeloid leukemia patients treated with tyrosine kinase inhibitors at the Department of Internal Medicine and Oncology, Semmelweis University, between 2003 and 2019 were analysed retrospectively. RESULTS: 88 patients received treatment, 73 patients were on therapy at the time of the analysis. Overall survival at 5 years was 86%, progression-free survival at 5 years was 70%. 9 patients died, 2 of them due to progressive disease. 38 patients needed 2nd line therapy, the main reason of treatment change was failure of therapy. Subsequent treatment modifications were conducted mostly because of intolerance. More than half of the patients on 1st line treatment reached major molecular response and 85% of the patients on treatment at the end of the analysis are in major molecular response. DISCUSSION: Based on our data, survival and therapeutic response of patients in our center are similar to the international results. CONCLUSION: This analysis provides real-world data about treatment results of chronic myeloid leukemia in the tyrosine kinase inhibitor era. Orv Hetil. 2021; 162(32): 1297-1302.

Management of antiplatelet therapy in acute coronary syndrome patients with thrombocytopenia / Akut coronaria szindrómán átesett thrombocytopeniás betegek thrombocytaaggregáció-gátló gyógyszeres kezelése.

Összefoglaló. Az akut coronaria szindrómán (ACS) átesett betegek kezelésének alappillére a kettos (aszpirin + klopidogrél ) thrombocytaaggregáció-gátló kezelés. Az immunthrombocytopeniás purpurás (ITP-s) betegek - és különösen azok, akik refrakter ITP miatt thrombopoetinanalóg kezelésben részesülnek - külön elbírálást igényelnek. 50-100 G/l thrombocytaszám közötti és vérzéses szövodménnyel nem rendelkezo ACS-s betegeken a gyógyszerkibocsátó stent beültetését követoen kettos thrombocytaaggregáció-gátló kezelést csak 1 hónapig kell alkalmazni (ez az idotartam átlagos vérzéses rizikójú betegeken 1 év), majd klopidogrél-monoterápia javasolt. Munkánk során a 2015. január 1. és 2020. október 1. között a Semmelweis Egyetem I. Belgyógyászati Klinikáján kezelt ITP-s betegek körében vizsgáltuk az ACS elofordulását és lefolyását. Klinikánkon az elmúlt 5 évben gondozott, 168 ITP-s beteg közül 3 beteg esetében alakult ki ACS. A refrakter ITP kezelésének részeként mind a 3 beteg thrombopoetinanalóg - (2 beteg romiplosztim-, 1 beteg eltrombopág-) kezelésben részesült. A 3 ITP-s betegünk egyikénél sem alakult ki vérzéses szövodmény a thrombopoetinanalóg-kezelés és a thrombocytaaggregáció-gátlás mellett. Elso betegünk esetében 5 év alatt három alkalommal alakult ki ACS (egy ízben fémstentet és két alkalommal gyógyszerkibocsátó stentet kapott). A második betegnél két alkalommal (1 év különbséggel), a harmadik betegnél egy esetben történt gyógyszerkibocsátó stent beültetése. ITP és ACS együttes fennállása esetén az akut és a hosszú távú gyógyszeres kezelés egyéni mérlegelést igényel. Ezen speciális betegcsoport számára a kezelési irányelv kidolgozása megfontolandó. Orv Hetil. 2021; 162(33): 1335-1340. Summary. Dual antiplatelet therapy (DAPT) consisting of aspirin and clopidogrel is essential in the treatment of acute coronary syndrome (ACS). Immune thrombocytopenic purpura (ITP) patients - and especially those receiving thrombopoietin analog (TPO) treatment - deserve special attention. In ACS patients with platelet counts between 50 G/L and 100 G/L and no bleeding symptoms, DAPT is indicated for 1 month after the placement of new generation drug-eluting stents (the length of treatment is 1 year in the case of patients with average bleeding risk) followed by clopidogrel monotherapy. In patients with average bleeding risk, DAPT is recommended for 1 year after the ACS. Our aim was to investigate the incidence and outcome of ACS in ITP patients, who were treated in our clinic between 1st January 2015 and 1st October 2020. Out of 168 patients treated for ITP, 3 patients suffered from ACS in the last 5 years. These patients received TPO treatment (2 patients subcutan romiplostim, 1 patient oral eltrombopag). None of these ITP patients treated with DAPT and with TPO analog suffered from bleeding complications. 1 patient developed ACS three times within the last 5 years (he received bare-metal stent once and drug-eluting stent twice). Drug-eluting stent was placed once in the third, and twice (with 1 year difference) in the second patient. Acute and long-term medication of patients suffering from both ITP and ACS is a challenging task and needs individual evaluation. Establishment of treatment guidelines for this special group is warranted. Orv Hetil. 2021; 162(33): 1335-1340.

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.

Screening and monitoring of the BTKC481S mutation in a real-world cohort of patients with relapsed/refractory chronic lymphocytic leukaemia during ibrutinib therapy.

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has revolutionised the therapeutic landscape of chronic lymphocytic leukaemia (CLL). Acquired mutations emerging at position C481 in the BTK tyrosine kinase domain are the predominant genetic alterations associated with secondary ibrutinib resistance. To assess the correlation between disease progression, and the emergence and temporal dynamics of the most common resistance mutation BTKC481S , sensitive (10-4 ) time-resolved screening was performed in 83 relapsed/refractory CLL patients during single-agent ibrutinib treatment. With a median follow-up time of 40 months, BTKC481S was detected in 48·2% (40/83) of the patients, with 80·0% (32/40) of them showing disease progression during the examined period. In these 32 cases, representing 72·7% (32/44) of all patients experiencing relapse, emergence of the BTKC481S mutation preceded the symptoms of clinical relapse with a median of nine months. Subsequent Bcl-2 inhibition therapy applied in 28/32 patients harbouring BTKC481S and progressing on ibrutinib conferred clinical and molecular remission across the patients. Our study demonstrates the clinical value of sensitive BTKC481S monitoring with the largest longitudinally analysed real-world patient cohort reported to date and validates the feasibility of an early prediction of relapse in the majority of ibrutinib-treated relapsed/refractory CLL patients experiencing disease progression.

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).

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.

[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.