Ruxolitinib and interferon-α2 combination therapy for patients with polycythemia vera or myelofibrosis: a phase II study.

We report the final 2-year end-of-study results from the first clinical trial investigating combination treatment with ruxolitinib and low-dose pegylated interferon-α2 (PEG-IFNα2). The study included 32 patients with polycythemia vera and 18 with primary or secondary myelofibrosis; 46 patients were previously intolerant of or refractory to PEGIFNα2. The primary outcome was efficacy, based on hematologic parameters, quality of life measurements, and JAK2 V617F allele burden. We used the 2013 European LeukemiaNet and International Working Group- Myeloproliferative Neoplasms Research and Treatment response criteria, including response in symptoms, splenomegaly, peripheral blood counts, and bone marrow. Of 32 patients with polycythemia vera, ten (31%) achieved a remission which was a complete remission in three (9%) cases. Of 18 patients with myelofibrosis, eight (44%) achieved a remission; five (28%) were complete remissions. The cumulative incidence of peripheral blood count remission was 0.85 and 0.75 for patients with polycythemia vera and myelofibrosis, respectively. The Myeloproliferative Neoplasm Symptom Assessment Form total symptom score decreased from 22 [95% confidence interval (95% CI):, 16-29] at baseline to 15 (95% CI: 10-22) after 2 years. The median JAK2 V617F allele burden decreased from 47% (95% CI: 33-61%) to 12% (95% CI: 6-22%), and 41% of patients achieved a molecular response. The drop-out rate was 6% among patients with polycythemia vera and 32% among those with myelofibrosis. Of 36 patients previously intolerant of PEG-IFNα2, 31 (86%) completed the study, and 24 (67%) of these received PEG-IFNα2 throughout the study. In conclusion, combination treatment improved cell counts, reduced bone marrow cellularity and fibrosis, decreased JAK2 V617F burden, and reduced symptom burden with acceptable toxicity in several patients with polycythemia vera or myelofibrosis. #EudraCT2013-003295-12.

Age-related prevalence and clinical significance of neutropenia - isolated or combined with other cytopenias: Real world data from 373 820 primary care individuals.

Neutropenia (NP), that is, an absolute blood neutrophil count (ANC) <1.5 g/L, accompanies various diseases. However, the clinical significance of NP, detected in routine complete blood cell counts (CBC) in primary care, is poorly characterized. Here, from a primary care resource with ANCs from >370 000 individuals, we identified and followed neutropenic subjects for the next 4 years for novel ICD-10 based diagnoses of viral infections and hematological malignancies (ie, previously identified major outcomes in NP individuals) in Danish nationwide health registers. Risk estimates were assessed for children/adolescents (1-18 years) and adults (19-90 years) in relation to NP severity, and for isolated NP, bi- or pancytopenias. We found that NP was observed in 4.9% of children and in 1.9% of adults. The lower the ANC, the likelier was a diagnosis of viral infections or hematological malignancies established during the ensuing 4 years. Among neutropenic children, unspecified viral infections predominated, followed by mononucleosis (with other cytopenias in only 7% and 25% of the cases, respectively). All NP children with acute leukemia presented with bi- or pancytopenia from start of follow-up. In NP adults, hepatitis, followed by HIV, were the most common infections, and acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDSs) the predominating hematological malignancies. Adult NP patients, subsequently diagnosed with hepatitis, HIV or AML, MDS, were bi- or pancytopenic in 42%, 47%, 90% and 91% of cases, respectively. Thus, presence of NP in even one CBC may be the first sign of a latent viral or hematological disorder requiring careful follow-up.

Apheresis principles in a patient with chronic myeloid leukemia during pregnancy: challenges in cell separation and assessing transcript levels.

BACKGROUND: Chronic myeloid leukemia (CML) is rarely diagnosed in pregnant women. CASE REPORT: We report a case of a pregnant woman who presented with a leukocyte count of 250 × 109 cells/L at gestational age (GA) 26 weeks and was diagnosed with CML in the chronic phase. Because the patient deliberately opted out of interferon α and tyrosine kinase inhibitor treatment, the main goal was to reduce the leukocyte count to postpone delivery beyond the number of weeks considered severely premature and avoid thromboembolic complications while continuously evaluating the clinical safety of the mother and fetus. Hence therapeutic leukapheresis was initiated, and we report the first application of an apheresis approach for this procedure using the Spectra Optia instrument without sedimentation agents. Leukapheresis was conducted 2 to 4 times per week for 9 weeks. RESULTS: During treatment the leukocyte count decreased remarkably, and the patient developed lymphopenia together with a paradoxical increase in her blood platelet count. Premature labor was induced at GA 35 weeks, and a healthy boy was delivered. Thereafter, the patient initiated imatinib treatment and was in major molecular and complete cytogenetic remission after 1 year. Despite the remarkable reduction of the leukocyte count, we observed a pronounced increase in expression of BCR-ABL1 transcripts, implying the need for close monitoring of patients with CML during pregnancy. CONCLUSIONS: We report a pregnant woman who was diagnosed with CML and treated solely with apheresis procedures using the Spectra Optia instrument for 9 weeks, ensuring the safe delivery of her child.

Thromboembolism prophylaxis in patients with Philadelphia-negative myeloproliferative neoplasms-Clinical practice among Nordic specialists.

BACKGROUND: Patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) have higher risks of developing thromboembolisms compared to the general population. International guidelines on the management of MPNs therefore include recommendations concerning thromboembolism prophylaxis. In clinical practice, strict adherence to guidelines may be challenging and dependent on factors such as physician experience, outpatient clinic setting, and access to therapy; however, no data exist on physician adherence or patient compliance to thromboembolism prophylaxis in MPNs. OBJECTIVES: The Nordic Myeloproliferative Neoplasm Study Group (NMPN) performed a survey among Nordic hematology specialists with the aim of documenting the implementation of international recommendations in a region of Northern Europe with similar healthcare systems. RESULTS: The study showed that Nordic specialists managed their patients in accordance with international guidelines concerning medical intervention, but to a lesser degree regarding the management of additional cardiovascular risk factors. The survey also drew attention to the common clinical dilemma of combining antiaggregatory agents with vitamin K antagonists (VKA), or novel oral anticoagulants (NOAC), as well as phlebotomy limits in female polycythemia vera patients. CONCLUSIONS: The results of this study highlight the importance of considering all risk factors for thrombosis and an optimal collaboration with the primary healthcare sector.

Myeloproliferative Neoplasms in Danish Twins.

OBJECTIVE: Myeloproliferative neoplasms (MPNs) are a heterogeneous group of diseases characterized by clonal hyperproliferation of immature and mature cells of the myeloid lineage. Genetic differences have been proposed to play a role in the development of MPNs. Monozygotic twin pairs with MPNs have been reported in a few case reports, but the MPN concordance pattern in twins remains unknown. METHOD: All twin pairs born in the period 1900-2010 were identified in the nationwide Danish Twin Registry. Only pairs with both twins alive on January 1, 1977, and those born thereafter were included to allow identification in the Danish National Patient Registry. RESULTS: A total of 158 twin pairs were registered with an MPN diagnosis: 36 monozygotic, 104 dizygotic, and 18 pairs with unknown zygosity. MPNs were diagnosed in both twins in 4 pairs. The probandwise concordance rates for monozygotic twin pairs were higher than for dizygotic twin pairs (15 vs. 0%; p = 0.016). CONCLUSION: An estimated concordance rate of 15% (95% CI 0.059-0.31) is modest, but given the rarity of MPNs this finding is clinically relevant and provides further support for the role of genetic predisposition in the development of MPNs.

Multidisciplinary Management of Mastocytosis: Nordic Expert Group Consensus.

Mastocytosis is a heterogeneous group of diseases defined by an increased number and accumulation of mast cells, and often also by signs and symptoms of mast cell activation. Disease subtypes range from indolent to rare aggressive forms. Mastocytosis affects people of all ages and has been considered rare; however, it is probably underdiagnosed with potential severe implications. Diagnosis can be challenging and symptoms may be complex and involve multiple organ-systems. In general it is advised that patients should be referred to centres with experience in the disease offering an individualized, multidisciplinary approach. We present here consensus recommendations from a Nordic expert group for the diagnosis and general management of patients with mastocytosis.

Haemostasis and safety measures before lumbar puncture in the haematology ward: the Danish routines.

BACKGROUND/AIMS: Thrombocytopenia and the increasing use and variety of antithrombotic drugs is a challenge prior to lumbar puncture. This study examined the Danish haematology practice regarding drug pausation, assessment of haemostasis and whether fundoscopy is a routine safety measure. METHODS: An online survey with questions pertaining to precautions of haemostasis and application of fundoscopy was sent by e-mail to all 12 haematology wards in Denmark. RESULTS: Eleven sites participated. Five (45%) reported no pausation of antiplatelet drugs at all. The mean platelet limit prior to lumbar puncture was 50 × 10(9)/l (range 10-50 × 10(9)/l). Seven (64%) sites had an international normalised ratio limit of 1.5, and the remaining 4 had values between 1.0 and 2.5. Two (18%) reported occasional use of thromboelastography or platelet analysis to assess the bleeding risk. Fundoscopy is routinely performed in 4 (36%) departments. CONCLUSION: We report considerable variation in the routine handling of antithrombotics and thrombocytopenia in patients set for lumbar puncture in Danish haematology departments. The diversity may be explained by and related to different opinions in the literature. Common national guidelines are warranted and there is a need for studies to establish an evidence-based approach for the management of patients at risk of bleeding when lumbar puncture or another invasive procedure is indicated.

Eosinophilia in routine blood samples as a biomarker for solid tumor development - A study based on the Copenhagen Primary Care Differential Count (CopDiff) Database.

BACKGROUND: Eosinophilia may represent an early paraclinical sign of malignant disease and a host anti-tumor effect. The association between eosinophilia and the development of solid tumors has never before been examined in an epidemiological setting. The aim of the present study was to investigate eosinophilia in routine blood samples as a potential biomarker of solid tumor development in a prospective design. MATERIAL AND METHODS: From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356 196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count during 2000-2007. From these, one DIFF was randomly chosen and categorized according to no (< 0.5 × 10(9)/l), mild (≥ 0.5-1.0 × 10(9)/l) or severe (≥ 1.0 × 10(9)/l) eosinophilia. From the Danish Civil Registration System and the Danish Cancer Registry we ascertained all-cause death and solid tumors within the first three years following the DIFF. Using multivariable logistic regression, odds ratios (OR) were calculated and adjusted for previous eosinophilia, sex, age, year, month, C-reactive protein, previous cancer and Charlson's Comorbidity Index. RESULTS: The risk of bladder cancer was increased with mild eosinophilia [OR 1.93 (CI 1.29-2.89), p = 0.0013]. No associations with eosinophilia were observed for the remaining solid cancers. CONCLUSION: We demonstrate that eosinophilia in routine blood samples associates with an increased risk of bladder cancer. Our data emphasize that additional preclinical studies are needed in order to shed further light on the role of eosinophils in carcinogenesis, where it is still unknown whether the cells contribute to tumor immune surveillance or neoplastic evolution.

Increase in circulating CD4⁺CD25⁺Foxp3⁺ T cells in patients with Philadelphia-negative chronic myeloproliferative neoplasms during treatment with IFN-α.

Recent reports have described complete or major molecular remission in patients with polycythemia vera after long-term treatment with the immunomodulatory agent IFN-α2. Accordingly, there are reasons to believe that the immune system is a key player in eradicating the JAK2 mutated clone in these patients. Foxp3(+) regulatory T cells play a pivotal role in maintaining immune homeostasis and, importantly, preventing immune reactivity to self-antigens; however, their suppressive activity can compromise an effective antitumor immune response, and high frequencies of regulatory T cells in peripheral blood have been reported in both hematologic and solid cancers. We have analyzed the number, phenotype, and function of circulating CD4(+)CD25(+)Foxp3(+) T cells in patients with chronic myeloproliferative neoplasms. Surprisingly, we found a marked expansion of this subset of lymphocytes in patients treated with IFN-α2 (13.0%; 95% confidence interval [CI] 10.8% to 15.2%) compared with healthy donors (6.1%; 95% CI 4.9% to 7.2%), patients with untreated chronic myeloproliferative neoplasms (6.9%; 95% CI 5.8% to 7.4%), or patients treated with hydroxyurea (5.8%; 95% CI 4.3% to 7.4%; P < .0001).

Eosinophilia in routine blood samples and the subsequent risk of hematological malignancies and death.

Eosinophilia may represent an early paraclinical sign of hematological malignant disease, but no reports exist on its predictive value for hematological malignancies. From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356,196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count during 2000-2007. From these, one DIFF was randomly chosen and categorized according to no (<0.5 × 10(9) /L), mild (≥ 0.5-1.0 × 10(9) /L) or severe (≥ 1.0 × 10(9) /L) eosinophilia. From the Danish Cancer Registry and the Danish Civil Registration System, we ascertained hematological malignancies and death within 3 years following the DIFF. Using multivariable logistic regression odds ratios (ORs) were calculated and adjusted for previous eosinophilia in a DIFF, sex, age, year, month, C-reactive protein, previous cancer, and comorbidity. ORs for developing Hodgkin's lymphoma (HL) was significantly increased in individuals exhibiting severe eosinophilia, OR = 9.09 (C.I. 2.77-29.84), P = 0.0003. The association with classical myeloproliferative neoplasms (cMPNs) showed an increasing risk with OR = 1.65 (1.04-2.61) P = 0.0322 and OR = 3.87 (1.67-8.96) P = 0.0016 for mild and severe eosinophilia. Eosinophilia was in a similar fashion associated with chronic lymphatic leukemia (CLL), OR = 2.57 (1.50-4.43), P = 0.0006 and OR = 5.00 (1.57-15.94), P = 0.0065, and all-cause death, OR of 1.16 (1.09-1.24), P < 0.0001 and 1.60 (1.35-1.91), P < 0.0001. We confirm associations between eosinophilia and HL and cMPNs, and in addition for the first time demonstrate a dose-dependent association between eosinophilia and CLL as well as death. Unexplained eosinophilia should prompt clinicians to consider conditions where early diagnosis may improve prognosis.

Eosinophilia in routine blood samples as a biomarker for solid tumor development - A study based on The Copenhagen Primary Care Differential Count (CopDiff) Database.

Background. Eosinophilia may represent an early paraclinical sign of malignant disease and a host anti-tumor effect. The association between eosinophilia and the development of solid tumors has never before been examined in an epidemiological setting. The aim of the present study was to investigate eosinophilia in routine blood samples as a potential biomarker of solid tumor development in a prospective design. Material and methods. From the Copenhagen Primary Care Differential Count (CopDiff) Database, we identified 356 196 individuals with at least one differential cell count (DIFF) encompassing the eosinophil count during 2000-2007. From these, one DIFF was randomly chosen and categorized according to no (< 0.5 × 10(9)/l), mild (≥ 0.5-1.0 × 10(9)/l) or severe (≥ 1.0 × 10(9)/l) eosinophilia. From the Danish Cancer Registry we ascertained solid tumors within the first three years following the DIFF. Using multivariable logistic regression, odds ratios (OR) were calculated and adjusted for previous eosinophilia, sex, age, year, month, C-reactive protein, previous cancer and Charlson's comorbidity index. Results. The risk for breast cancer was significantly lower in individuals exhibiting mild eosinophilia than in individuals with normal eosinophil counts [OR (95% confidence intervals) = 0.51 (0.35-0.76), p = 0.0005]. The risk of bladder cancer, however, increased with severity of eosinophilia [2.27 (1.53-3.39), p < 0.0001 and 2.62 (0.96-7.14), p = 0.0592 for mild and severe eosinophilia, respectively]. No associations with eosinophilia were observed for remaining solid cancers. Conclusion. We demonstrate that eosinophilia in routine blood samples associate with a decreased risk of breast cancer and an increased risk of bladder cancer. Our data emphasize that additional preclinical studies are needed in order to shed further light on the role of eosinophils in carcinogenesis, where it is still unknown whether the cells contribute to tumor immune surveillance or neoplastic evolution.

Isolation and killing of candidate chronic myeloid leukemia stem cells by antibody targeting of IL-1 receptor accessory protein.

Chronic myeloid leukemia (CML) is genetically characterized by the Philadelphia (Ph) chromosome, formed through a reciprocal translocation between chromosomes 9 and 22 and giving rise to the constitutively active tyrosine kinase P210 BCR/ABL1. Therapeutic strategies aiming for a cure of CML will require full eradication of Ph chromosome-positive (Ph(+)) CML stem cells. Here we used gene-expression profiling to identify IL-1 receptor accessory protein (IL1RAP) as up-regulated in CML CD34(+) cells and also in cord blood CD34(+) cells as a consequence of retroviral BCR/ABL1 expression. To test whether IL1RAP expression distinguishes normal (Ph(-)) and leukemic (Ph(+)) cells within the CML CD34(+)CD38(-) cell compartment, we established a unique protocol for conducting FISH on small numbers of sorted cells. By using this method, we sorted cells directly into drops on slides to investigate their Ph-chromosome status. Interestingly, we found that the CML CD34(+)CD38(-)IL1RAP(+) cells were Ph(+), whereas CML CD34(+)CD38(-)IL1RAP(-) cells were almost exclusively Ph(-). By performing long-term culture-initiating cell assays on the two cell populations, we found that Ph(+) and Ph(-) candidate CML stem cells could be prospectively separated. In addition, by generating an anti-IL1RAP antibody, we provide proof of concept that IL1RAP can be used as a target on CML CD34(+)CD38(-) cells to induce antibody-dependent cell-mediated cytotoxicity. This study thus identifies IL1RAP as a unique cell surface biomarker distinguishing Ph(+) from Ph(-) candidate CML stem cells and opens up a previously unexplored avenue for therapy of CML.

The multidisciplinary approach to eosinophilia.

Eosinophilic granulocytes are normally present in low numbers in the bloodstream. Patients with an increased number of eosinophilic granulocytes in the differential count (eosinophilia) are common and can pose a clinical challenge because conditions with eosinophilia occur in all medical specialties. The diagnostic approach must be guided by a thorough medical history, supported by specific tests to guide individualized treatment. Neoplastic (primary) eosinophilia is identified by one of several unique acquired genetic causes. In contrast, reactive (secondary) eosinophilia is associated with a cytokine stimulus in a specific disease, while idiopathic eosinophilia is a diagnosis by exclusion. Rational treatment is disease-directed in secondary cases and has paved the way for targeted treatment against the driver in primary eosinophilia, whereas idiopathic cases are treated as needed by principles in eosinophilia originating from clonal drivers. The vast majority of patients are diagnosed with secondary eosinophilia and are managed by the relevant specialty-e.g., rheumatology, allergy, dermatology, gastroenterology, pulmonary medicine, hematology, or infectious disease. The overlap in symptoms and the risk of irreversible organ involvement in eosinophilia, irrespective of the cause, warrants that patients without a diagnostic clarification or who do not respond to adequate treatment should be referred to a multidisciplinary function anchored in a hematology department for evaluation. This review presents the pathophysiology, manifestations, differential diagnosis, diagnostic workup, and management of (adult) patients with eosinophilia. The purpose is to place eosinophilia in a clinical context, and therefore justify and inspire the establishment of a multidisciplinary team of experts from diagnostic and clinical specialties at the regional level to support the second opinion. The target patient population requires highly specialized laboratory analysis and therapy and occasionally has severe eosinophil-induced organ dysfunction. An added value of a centralized, clinical function is to serve as a platform for education and research to further improve the management of patients with eosinophilia. Primary and idiopathic eosinophilia are key topics in the review, which also address current research and discusses outstanding issues in the field.

A novel immunohistochemical sequential multi-labelling and erasing technique enables epitope characterization of bone marrow pericytes in primary myelofibrosis.

AIM: In Philadelphia (Ph)-negative chronic myeloproliferative neoplasms, increased microvascular density, bizarre vessel architecture and increased number of pericytes are among the distinct histopathological features. The aim of this study was to characterize bone marrow pericytes in primary myelofibrosis (PMF) using a novel multi-labelling immunohistochemical technique. METHODS AND RESULTS: Bone marrow biopsies from a normal donor (n = 1) and patients with PMF (n = 3) were subjected to an immunohistochemical sequential multi-labelling and erasing technique (SE-technique). Antigens of interest in the first and/or second layer were detected with an immunoperoxidase system and visualized with aminoethylcarbazole. After imaging, erasing and blocking of immunoreagents, the slides were stained with a traditional double immunolabelling procedure. In addition, we applied a Photoshop® colour palette, creating a single composite image of the sequential staining procedures. We successfully applied four layers of antibodies on one slide using CD146, smooth muscle actin, CD34, CD271 and Ki67 in different combinations. The SE-technique significantly improves morphological and phenotypical studies in bone marrow specimens. CONCLUSIONS: To our knowledge, the SE-technique is the first to multi-label antigens, identifying vessel and pericyte architecture in bone marrow by light microscopy. This technique may unravel novel aspects of the composition of the microvessel structures in patients with PMF and related neoplasms.

Outcomes and endpoints in clinical trials supporting the marketing authorisation of treatments in paediatric acute lymphoblastic leukaemia.

The improvement in acute lymphoblastic leukaemia (ALL) treatment has led research efforts to focus on the unmet medical needs of an increasingly smaller patient cohort with resistant leukaemia and to develop more-targeted agents. Survival and response rates remain the most-prevalent endpoints in paediatric ALL research, but other intermediate clinical endpoints and molecular biomarkers for efficacy and mid- and long-term safety endpoints are also being investigated. The success of current ALL treatment appears to be driving new paradigms to optimise clinical drug development, while at the same time, regulatory tools in place are supporting meaningful drug development in the area.

A retrospective cohort study of patients with eosinophilia referred to a tertiary centre.

INTRODUCTION: Patients with eosinophilia (an increased number of eosinophilic granulocytes > 0.5 × 108/l in the blood) are encountered in all medical specialties and frequently need thorough workup to identify the eliciting causes and decide whether treatment is indicated. In Denmark, highly specialised centres for eosinophilic diseases or conditions have been established to provide a foundation for the management of complicated cases. Here, we present experiences from such a multidisciplinary centre. METHODS: This was a retrospective study of all patients seen in our tertiary centre for eosinophilia in the 2016-2019 period. RESULTS: Referrals mainly derived from specialised secondary care and to a lesser degree from primary care physicians. Patients were either asymptomatic or exhibited symptoms from up to three organ systems and presented a median eosinophil count of 1.7 × 108/l. Up to eight new clonality analyses or imaging studies per patient were performed after referral. One of these, T-cell receptor analysis, was performed frequently but provided limited information, whereas, e.g., flow cytometry proved more clinically applicable owing to its broader diagnostic range. In total, 51 patients were evaluated and classified as secondary (59%), myeloid neoplasm with PDGFRA rearrangement (2%), idiopathic hypereosinophilic syndrome (31%) and idiopathic hypereosinophilia (8%). CONCLUSION: The value of a multidisciplinary and versatile approach in a highly specialised centre has a positive impact on diagnostic processes as well as on the evaluation of treatment need. FUNDING: none. TRIAL REGISTRATION: not relevant.

IFN-α with dasatinib broadens the immune repertoire in patients with chronic-phase chronic myeloid leukemia.

In chronic myeloid leukemia (CML), combination therapies with tyrosine kinase inhibitors (TKIs) aim to improve the achievement of deep molecular remission that would allow therapy discontinuation. IFN-α is one promising candidate, as it has long-lasting effects on both malignant and immune cells. In connection with a multicenter clinical trial combining dasatinib with IFN-α in 40 patients with chronic-phase CML (NordCML007, NCT01725204), we performed immune monitoring with single-cell RNA and T cell receptor (TCR) sequencing (n = 4, 12 samples), bulk TCRß sequencing (n = 13, 26 samples), flow cytometry (n = 40, 106 samples), cytokine analyses (n = 17, 80 samples), and ex vivo functional studies (n = 39, 80 samples). Dasatinib drove the immune repertoire toward terminally differentiated NK and CD8+ T cells with dampened functional capabilities. Patients with dasatinib-associated pleural effusions had increased numbers of CD8+ recently activated effector memory T (Temra) cells. In vitro, dasatinib prevented CD3-induced cell death by blocking TCR signaling. The addition of IFN-α reversed the terminally differentiated phenotypes and increased the number of costimulatory intercellular interactions and the number of unique putative epitope-specific TCR clusters. In vitro IFN-α had costimulatory effects on TCR signaling. Our work supports the combination of IFN-α with TKI therapy, as IFN-α broadens the immune repertoire and restores immunological function.

Genomic profiling of a randomized trial of interferon-α vs hydroxyurea in MPN reveals mutation-specific responses.

Although somatic mutations influence the pathogenesis, phenotype, and outcome of myeloproliferative neoplasms (MPNs), little is known about their impact on molecular response to cytoreductive treatment. We performed targeted next-generation sequencing (NGS) on 202 pretreatment samples obtained from patients with MPN enrolled in the DALIAH trial (A Study of Low Dose Interferon Alpha Versus Hydroxyurea in Treatment of Chronic Myeloid Neoplasms; #NCT01387763), a randomized controlled phase 3 clinical trial, and 135 samples obtained after 24 months of therapy with recombinant interferon-alpha (IFNα) or hydroxyurea. 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. Among JAK2-mutated patients treated with IFNα, those with CHR had a greater reduction in the JAK2 variant allele frequency (median, 0.29 to 0.07; P < .0001) compared with those not achieving CHR (median, 0.27 to 0.14; P < .0001). In contrast, the CALR variant allele frequency did not significantly decline in those achieving CHR or in those not achieving CHR. Treatment-emergent mutations in DNMT3A were observed more commonly in patients treated with IFNα compared with hydroxyurea (P = .04). Furthermore, treatment-emergent DNMT3A mutations were significantly enriched in IFNα-treated patients not attaining CHR (P = .02). A mutation in TET2, DNMT3A, or ASXL1 was significantly associated with prior stroke (age-adjusted odds ratio, 5.29; 95% confidence interval, 1.59-17.54; P = .007), as was a mutation in TET2 alone (age-adjusted odds ratio, 3.03; 95% confidence interval, 1.03-9.01; P = .044). At 24 months, we found mutation-specific response patterns to IFNα: (1) JAK2- and CALR-mutated MPN exhibited distinct molecular responses; and (2) DNMT3A-mutated clones/subclones emerged on treatment.