Cytoreductive treatment in real life: a chart review analysis on 1440 patients with polycythemia vera

Purpose Patients with polycythemia vera (PV) show an elevated incidence of thromboembolic complications and decreased survival when compared to age-matched healthy individuals. Hypercellularity as indicated by elevated hematocrit, pathophysiological changes induced by the JAK2 driver mutation and cardiovascular risk factors contribute to the increased incidence of thromboembolic events. Higher age and a history of thromboembolic events define a high-risk population of PV patients. Depending on the individual risk profile, phlebotomy or pharmacologic cytoreduction is recommended in combination with low-dose acetylsalicylic acid. Stringent cytoreduction is required for effective risk reduction. However, in recent reports, the rate of thromboembolic complications in PV patients under cytoreductive therapy appears still elevated compared to healthy individuals. This study reports on a chart review to assess for cytoreductive therapy of 1440 PV patients in real life. Methods Forty-two eligible hematologists/oncologists in private practice treating patients with MPN were recruited to participate in a paper–pencil-based survey conducted between January 2019 and March 2020 in Germany. Physicians were asked to report primary documented data obtained from patient charts. Descriptive analyses were conducted to assess for patient characteristics, treatment modalities, risk factors and thromboembolic complications. Results Data were collected from the patient charts of 1440 individuals diagnosed with PV. The patient population was older than those reported in multicenter trials with a median age of 72.2 years at the time of reporting and 63.5 years at diagnosis. Age was the main factor accounting for high-risk status with 84.7% of patients being above the age of 60 followed by thromboembolic complications reported in 21.3% of patients. The use of pharmacologic cytoreduction was highly variable between participating centers with an average of 60.7% and a range of 10.1–100%. Hydroxyurea was the most frequently used drug followed by ruxolitinib, while interferons were reported for a minority of patients. For 35.4% of patients a persistent need for phlebotomy in addition to cytoreductive treatment was reported. Although presence of high-risk criteria and insufficient disease control were reported as main triggers to initiate pharmacologic cytoreduction, 28.1% had elevated hematocrit values (> 45%) and 38.6% showed persistence of elevated leukocyte count (> 109/l) while on cytoreductive treatment. In contrast, physician-reported symptom burden was lower than published in clinical trials and patient-reported outcomes. The rate of patients experiencing thromboembolic complications was 32.2% at any time and 14.3% after diagnosis with most patients receiving acetylsalicylic acid and 10.8% remaining on oral anticoagulants or heparin. Conclusions Cytoreductive treatment of high-risk PV in real life is highly variable regarding indication for cytoreduction and definition of therapy resistance. This study highlights the need for (i) improved risk stratification for thromboembolic events, (ii) consequent indication of pharmacologic cytoreduction in high-risk PV and (iii) attention to signs of therapy resistance that can trigger an earlier and stringent switch to second line agents.

Clonal Dynamics of JAK2V617F and Non-Driver Mutations in Polycythemia Vera and Essential Thrombocythemia Patients Receiving Hydroxyurea Therapy

Introduction : Hydroxyurea (HU) is the most widely used cytoreductive treatment for patients with essential thrombocythemia (ET) and polycythemia vera (PV) at high risk of thrombosis. It remains unknown whether long-term HU therapy modulates or promotes the acquisition of mutations in non-driver (ND) genes, especially, when assessing hematological (HR) and molecular (MR) response. The objective of the study was to analyze the clonal dynamics of ND genes in HR and MR with HU in a cohort of JAK2V617F-mutated PV and ET patients. Method s: The study included 144 JAK2V617F positive patients (PV n = 73, TE n = 71) receiving HU as first-line cytoreductive treatment. The baseline sample (before HU treatment) and at the timepoint of best molecular response to JAK2V617F were analyzed. The allelic burden of J AK2V617F was assessed by allele-specific PCR and the mutational profile of ND genes was analyzed by next generation sequencing with a custom panel including 27 myeloid-associated genes. HR was defined according to the criteria of the European LeukemiaNet 2009 and MR of JAK2V617F was defined as complete, major, partial and no response (Table I). Results : Median molecular follow-up was 54.1 months for PV and 55.5 months for ET. Patients with PV were more likely to be males (p<0.001), and displayed higher leukocyte count (p<0.001) compared to those with ET. The respective numbers of deaths, leukemic transformations and fibrotic progressions were: 22 (30%), 4 (5%), 6 (8%) for PV cases, and 19 (27%), 1 (1%), 0 (0%) for ET patients. At baseline, a total of 62 somatic mutations in ND genes were detected in 42/73 (57%) PV patients while 58 were detected in 36/71 (51%) ET patients. Complete HR was observed in 102 patients: 44 (60%) PV and 58 (81%) ET. Partial MR in 67 cases: 35 (48%) PV and 32 (45%) ET and major or complete MR in 21 cases: 8 (11%) PV and 13 (18%) ET. The median duration of HU treatment was 45.8 months (range: 17.5-189.5) for PV and 45.6 months (range: 14.6-168.6) for ET. The most frequently mutated genes detected at pre-therapy samples were TET2 (34%), ASXL1 (12%), SF3B1 (7%) and EZH2 (5%) in PV patients, and TET2 (34%), ASXL1 (13%), DNMT3A (13 %) and SRSF2 (5%) in ET patients. No significant differences were observed in the MR (p=0.358) or HR (p=0.917) according to the presence or absence of mutations in ND genes at baseline. Clonal dynamics of DNMT3A, ASXL1, and TET2 (DAT) genes were not modulated by HU therapy to the same extent as JAK2V617F. Disappearance and emergence of additional mutations in DAT genes were observed independently of the molecular response achieved by the JAK2V617F clone. These findings suggest the existence of clones with mutations in ND genes independent from the pathogenic driver clone, and the lack of modulation by HU treatment. Finally, an increase of allelic burden or the appearance of mutations in TP53, a gene related to progression, and in other DNA repair genes (PPM1D and CHEK2) was observed in 14 (19.1%) PV patients and 9 (12.6%) ET cases during HU treatment. However, no increased risk of myelofibrotic transformation or progression to acute myeloid leukemia was observed in these patients. Conclusion s: Pre-treatment ND mutations are not associated with HR and MR to HU in JAK2V617F-mutated patients. 2. The clonal dynamics of ND mutations (decrease, increase, appearance, disappearance) are not related to the evolutionary dynamics of JAK2V617F. 3. An increase or appearance of progression-related mutations in TP53 and/or other genes of the DNA repair pathway such as CHEK2 and PPM1D is observed during HU treatment. Acknowledgments : Instituto de Salud Carlos III-FEDER, PI16/0153, PI19/0005, 2017SGR205, PT20/00023 and XBTC. Figure 1 Figure 1. Disclosures Salar: Janssen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Gilead: Research Funding; Celgene: Consultancy, Speakers Bureau. Besses: Gilead: Research Funding. Bellosillo: Thermofisher Scientific: Consultancy, Speakers Bureau; Qiagen: Consultancy, Speakers Bureau; Roche: Research Funding, Speakers Bureau.

Chronic Exposure to Cytoreductive Treatment Shapes Clonal Evolution in Myeloproliferative Neoplasms

Introduction: Myeloproliferative neoplasms (MPN) are a heterogeneous group of chronic myeloid malignancies resulting from the combination of a driver mutated gene (JAK2, MPL or CALR) and a variety of acquired additional somatic mutations. Although next-generation sequencing (NGS) has identified high molecular risk mutations associated with adverse prognosis (Vannucchi et al., Leukemia, 2013 , Guglielmelli et al., Leukemia, 2014 ), the clonal evolution of these mutations remains poorly described. Chronic exposure to cytoreductive treatment, especially genotoxic drugs such as hydroxyurea (HU), could impact clonal evolution. A previous study suggested that Interferon-α (IFN) could limit the accumulation of cytogenetic abnormalities compared to HU (Mondello et al., Blood, 2018). The objective of our study was to describe the long-term evolution of the mutational landscape in the era of NGS in a large cohort of MPN patients. Methods: A total of 1538 consecutive patients were diagnosed with MPN according to WHO criteria and followed in our hospital between January 2011 and January 2021. This study included 1039 of them in whom a NGS molecular analysis targeting 36 myeloid genes with a sensitivity of 1% was performed at diagnosis and/or during follow-up. Patients with only one NGS (n=588), AML/MDS transformation at either the first (n=3) or the second NGS (n=2) were excluded from the analysis. Serial NGS data obtained in chronic MPN phase were thus analyzed for 446 patients. Clinical and biological characteristics at time of diagnosis and follow-up were collected from medical charts and electronic medical records. Mutation rates per year were calculated for each gene as the difference in the number of mutations between first and last NGS divided by the time interval (in years) between both NGS. Results : Median age at MPN diagnosis in our whole cohort was 51 years [IQR 41-60]. Our cohort included 167 (37%), 205 (46%) and 64 (14%) patients with Polycythemia Vera (PV), Essential thrombocythemia (ET) and primary myelofibrosis (MF) respectively. 279 patients (63%) had at least one additional mutation at first NGS, and respectively 27 (6%) and 104 (23%) patients had TP53 and high molecular risk mutations. Median interval between MPN diagnosis and the first NGS was 6.5 years [IQR 1.7-13] while median time between the first and the last NGS was 2.5 years [IQR 1.6-4, range 0.3-14.3]. Overall, 178 patients (39.9%) acquired an additional mutation at last NGS evaluation, most frequently involving TET2, DNMT3A, ASXL1, TP53 and NFE2 genes . To study the impact of chronic MPN therapy on clonal evolution, we focused on patients who electively received HU (n=112) or IFN (n=92) as a monotherapy, or did not receive any cytoreductive treatment (n=119) between the first and the last NGS. The remaining patients received ruxolitinib (n=44), anagrelide (n=10), vercyte (n=7) or polytherapy (n=62). At last follow-up, 74 patients receiving IFN (80.4%) and 65 (58%) treated with HU had a complete hematological response. When combining all additional mutations, the global mutation rate per year did not significantly differ between treatment groups. When analyzing individual genes, TP53 mutation rate was higher in patients treated with HU compared to the patients receiving IFN (p=0.014) or not treated (p=0.008) (Figure). MDS/AML evolution occurred in 4 patients (3.6%) treated with HU, 2 (1.7%) without cytoreductive therapy versus none of the 92 patients treated with IFN (ns). In the whole cohort, MDS/AML evolution was significantly increased in patients harboring TP53 mutations (p= 0.004). In contrast, DNMT3A mutation rate was significantly increased in patients receiving IFN compared to patients treated with HU (p=0.045) (Figure). The latest result is in line with previous observations showing that loss of DNMT3A could confer resistance to IFN in a JAK2-V617F mouse model (Stetka et al., Blood, 2020). Conclusion: Our results highlight the impact of chronic cytoreductive therapy on clonal evolution shaping in MPN. IFN limits the emergence of TP53 mutated clones compared to HU, thus potentially reducing the risk of leukemogenesis. Emergence of DNMT3A mutated clones under IFN therapy requires further exploration and could potentially play a role in therapeutic resistance. This study on a large clinically and biologically annotated cohort illustrates how serial NGS analysis may guide therapeutic options for MPN patients. Figure 1 Figure 1. Disclosures Raffoux: PFIZER: Consultancy; ASTELLAS: Consultancy; ABBVIE: Consultancy; CELGENE/BMS: Consultancy. Kiladjian: AbbVie: Membership on an entity's Board of Directors or advisory committees; AOP Orphan: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Incyte Corporation: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Taiho Oncology, Inc.: Research Funding; PharmaEssentia: Other: Personal fees. Benajiba: Pfizer: Research Funding; Gilead: Research Funding.

SYSTEMIC MASTOCYTOSIS: MULTIDISCIPLINARY APPROACH

Systemic mastocytosis (SM) is a heterogeneous group of diseases that affect almost exclusively adults and are defined by the proliferation and accumulation of clonal mast cells (MC) in various tissues. Disease subtypes range from indolent to rare but aggressive forms. Although SM is classified as a rare disease, it is believed to be likely underdiagnosed. Major signs and symptoms mainly depend on MC activation and less frequently to organ infiltration, typical of more aggressive variants. Diagnosis may be challenging, and symptoms can be aspecific and involve several organs. It is advisable to refer patients to specialized centers, having sufficient knowledge of the disease, sensitive diagnostic procedures, offering a personalized and multidisciplinary diagnostic approach, including at least hematological, allergological, dermatological and rheumatological evaluations. A precise and timely diagnosis is required for: a) adequate counseling of patients and their physicians; b) beginning of symptomatic treatment (anti-mediator therapy); c) prevention of severe manifestations of the disease (i.e., recurrent anaphylaxis, osteoporosis and bone fractures); d) cytoreductive treatment of advanced SM variants. This review aims to summarize the main manifestations of the disease and describe the ideal diagnostic approach for adult patients with suspected SM, giving physicians the main notions for correct patient diagnosis and management. This review also highlights the importance of a multidisciplinary approach in this very complex disease.

Chemotherapy in Neuroendocrine Tumors

The role for cytotoxic chemotherapy in patients with well-differentiated neuroendocrine tumors (NETs) remains debated. Compared to patients with poorly differentiated neuroendocrine carcinomas (NECs) where chemotherapy is utilized ubiquitously, chemotherapy may play a more select role in patients with certain types of NETs (e.g., pancreatic tumors, higher grade tumors, and tumors possessing DNA damage repair defects). The primary types of chemotherapy that have been tested in patients with NETs include alkylating agent- and platinum agent-based combinations. Across regimens, chemotherapy appears to elicit greater antitumor activity in patients with pancreatic or grade 3 NETs. The role for chemotherapy in lower grade extra-pancreatic NETs remains undefined. Furthermore, while chemotherapy has demonstrated clinically meaningful benefit for patients in the systemic setting, its role in the adjuvant or neoadjuvant setting is as-of-yet undetermined. Finally, efforts to combine chemotherapy with targeted therapy and peptide receptor radionuclide therapy are ongoing, in hopes of improving the cytoreductive treatment options for patients with NETs.

Genomic Profiling of a Randomized Trial of Interferon-α versus Hydroxyurea in MPN Reveals Mutation-Specific Responses

Background Although somatic mutations influence the pathogenesis, phenotype, and outcome of myeloproliferative neoplasms (MPN), little is known about their impact on molecular response to cytoreductive treatment. Methods We performed targeted next-generation sequencing (NGS) on 202 pre-treatment samples obtained from patients with MPN enrolled in the DALIAH trial (randomized controlled phase III clinical trial, NCT01387763) and 135 samples obtained after 24 months of therapy with recombinant interferon-alpha (IFNα) or hydroxyurea (HU). The primary aim was to evaluate the association between complete clinicohematologic response (CHR) at 24 months and molecular response through sequential assessment of 120 genes using NGS. Results Among JAK2-mutated patients treated with IFNα, those with CHR had a greater reduction in the JAK2 variant allele frequency (VAF) (median 0.29 to 0.07; p<0.0001) compared with those not achieving CHR (median 0.27 to 0.14; p<0.0001). In contrast, the CALR VAF did not significantly decline in neither those achieving CHR nor those not achieving CHR. Treatment-emergent mutations in DNMT3A were observed more commonly in patients treated with IFNα compared with HU, p=0.04. Furthermore, treatment-emergent DNMT3A-mutations were significantly enriched in IFNα treated patients not attaining CHR, p=0.02. A mutation in TET2, DNMT3A, or ASXL1 was significantly associated with prior stroke (age-adjusted OR=5.29 [95% CI, 1.59-17.54]; p=0.007) as was a mutation in TET2 alone (age-adjusted OR=3.03 [95% CI, 1.03-9.01]; p=0.044). Conclusion At 24 months, we found mutation-specific response patterns to IFNα: (1) JAK2- and CALR-mutated MPN demonstrated distinct molecular responses and (2) DNMT3A-mutated clones/subclones emerged on treatment.

Intraoperative photodynamic therapy and hyperthermic intraperitoneal chemotherapy in cytoreductive treatment of patients with disseminated mucinous carcinoma of appendix

The article presents the experience of surgical treatment of 57 patients with peritoneal pseudomyxoma of appendicular genesis. In 32 (56.1%) patients, the operation was supplemented with intraoperative photodynamic therapy (IOPDT). In the other 25 (43.9%) patients, hyperthermic intraperitoneal chemotherapy (HIPEC) was performed. The analysis according to the value of the peritoneal carcinomatosis index, completeness of cytoreduction, the volume of operations performed, postoperative complications and hospital mortality, as well as long-term treat- ment results in two groups is presented. It was shown that with significantly worse results in terms of cytoreduction completeness obtained in the IOPDT group compared to the HIPEC group, the 5-year survival rate in the HIPEC group was 86.6%, with IOPDT - 65.2%. At the same time, in the IOPDT group, the rate of postoperative complications was significantly lower (11.1%), and there was no mortality; in the HIPEC group, these indicators were 23.8% and 12.0%, respectively. The results obtained indicate that the IOPDT method is an effective and promising direction in the surgical treatment of peritoneal pseudomyxoma.

Rapid Cytoreduction by Plateletapheresis in the Treatment of Thrombocythemia

The objective of this chapter is to provide a systematic overview of current knowledge regarding therapeutic apheresis—primarily therapeutic plateletapheresis (TP)—and to summarize evidence-based practical approaches related to cytapheresis treatment of “hyperthrombocytosis” or “extreme thrombocytosis” (ETC). Our results of platelet (Plt) quantitative/qualitative analyses and evaluation of efficacy of apheresis systems/devices—on the basis of Plt removal and in vivo Plt depletion—will be presented. Our preclinical researches confirmed that in Plt concentrates, the initial ratio of discoid shapes was 70%, spherical 20%, and less valuable (dendritic/balloonized) shapes 10%—with morphological score of platelets (MSP = 300–400). After storage, the ratio of discoid and spherical shapes was decreased, while the less valuable ones progressively increased (MSP = 200). Electron microscopy has shown discoid shapes with typical ultrastructural properties. Spherical shapes with reduced electron density and peripheral location of granules/organelles were detected. Also, dendritic shapes with cytoskeletal “rearrangement,” membrane system integrity damages, and pseudopodia formations were documented. Our clinical study demonstrated that TP was useful in ETC treatment and should help prevention of “thrombo-hemorrhagic” events—until chemotherapy, antiplatelet drugs, and other medication take effect. During TP treatment, Plt count and morphology/ultrastructure were examined. Plt functions by multiplate analyzer were evaluated. We concluded that intensive TP was an effective, safe, and rapid cytoreductive treatment for ET.

Interferon in Polycythemia Vera (PV) Yields Improved Myelofibrosis-Free and Overall Survival

Introduction: Polycythemia vera (PV) progression to myelofibrosis (MF) is associated with significant morbidity and mortality. Recombinant interferon alfa (rIFN-α) is the only disease-modifying treatment shown to reverse marrow fibrosis, but the myelofibrosis-free survival (MFS) and overall survival (OS) benefit associated with rIFN-α treatment is yet to be determined. In our preliminary analysis of 306 PV patients (pts) (Abu-Zeinah et al. ASH 2019), those treated with rIFN-α had a longer MFS and OS compared to those treated with hydroxyurea (HU) or phlebotomy-only (PHL-O). Herein, we present the final analysis comparing MFS and OS of 470 PV pts treated with rIFN-α, HU, or PHL-O. Methods: This single-center retrospective study at Weill Cornell Medicine (WCM) was approved by the WCM institutional review board. Pts were identified by an automated query of the electronic medical record system for the diagnosis of PV and were included if they met the PVSG criteria (1974-2007), WCM criteria (2008-2016) (Silver et al. Blood 2013), and the WHO 2016 criteria (2016-2020). Post-PV MF (PPVMF) diagnosis was made according to IWG-MRT criteria. Both intention-to-treat (ITT) and on-treatment analyses compared the MFS and OS by treatment group and duration, respectively. In the ITT analysis, pts were grouped to rIFNa or HU according to the first treatment they received for at least one year or to PHL-O if no cytoreductive treatment was given. MFS and OS were estimated using Kaplan-Meier methods and the log-rank test compared survival between treatment arms in ITT analysis. Multivariable analysis of PPVMF risk and mortality was performed using a Cox proportional hazards model. Results: The 470 PV pts identified had a median age of 54 years (range 20-94) at diagnosis; 229 (49%) were women. The median follow-up was 10 years (range 0-45). The primary treatment was rIFN-a in 94 (20%), HU in 188 (40%), other drugs or combinations in 55 (12%), and PHL-O in 133 (28%). The median age at diagnosis for rIFN-a, HU and PHL-O groups was 49, 58 and 54 years respectively (p <0.001) (Table 1). The median MFS for all pts was 23.8 years and for rIFN-a, HU, and PHL-O groups was 32.5, 22.6, and 20.5 years respectively (p <0.001) (Fig 1A-B). The median OS for all pts was 26.7 years and for rIFN-a, HU, and PHL-O groups was 27.7, 25.9 and 21.3 respectively (p<0.01) (Fig 1C-D). In multivariable analysis including age, sex, CV risk factors and thrombosis history, the rIFN-a group had a lower risk of MF compared to the HU group (HR = 0.42, p =0.008) and the PHL-O group (HR = 0.24, p<0.001). Likewise, the rIFN-a group had a lower risk of death compared to the HU group (HR = 0.33, p=0.01) and the PHL-O group (HR 0.3, p=0.001) independent of age. The HU group had a lower risk of PPVMF compared to PHL-O (HR 0.45, p=0.005) but no OS difference. Analysis of longitudinal bone marrow samples showed significantly less MF 2-3 fibrosis in rIFN-a compared to the HU and PHL-O groups (Figure 2). Time on treatment multivariable analysis showed that rIFN-a reduced PPVMF by 6% and all-cause mortality by 8% per year (HR = 0.94, p <0.001 and HR = 0.92, p<0.001 respectively), independent of age, thrombosis history, CV risk factors, or other treatments. On the other hand, HU was not associated with a risk reduction of either MF or mortality. The discontinuation rate of rIFN-a or HU due to toxicity was similar at 2.2 and 2.8 per 100 patient-years. Discussion: This is the largest single center study in PV using universal diagnostic criteria showing the MFS and OS advantage with rIFN-a over HU or PHL-O, and its similar rates of toxicity to HU. The evidence suggests that early cytoreductive treatment rather than PHL-O is advantageous. Treatment with PHL-O was associated with a higher risk of MF than either rIFN-a or HU. Conclusion: Our results support early use of rIFN-a as a safe, disease-modifying treatment of rigorously defined PV to delay and potentially prevent PPVMF, and prolong overall survival of PV pts. Disclosures Ritchie: Jazz pharmaceuticals: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Abbvie: Honoraria; Sierra Oncology: Honoraria; Incyte: Speakers Bureau; Novartis: Honoraria. Silver:PharmaEssentia: Speakers Bureau. OffLabel Disclosure: Interferon alfa has been used off label in the treatment of MPN for decades