How we treat paroxysmal nocturnal hemoglobinuria: A consensus statement of the Canadian PNH Network and review of the national registry.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematologic disease characterized by intravascular hemolysis, thrombophilia, and marrow failure. Its phenotype is due to absent or reduced expression of GPI-linked complement regulators and subsequent sensitivity of hematopoietic cells to complement-mediated damage and lysis. Introduction of the terminal complement inhibitor eculizumab drastically improved outcomes in PNH patients; however, despite this improvement, there remain several challenges faced by PNH patients and physicians who care for them. One of the most important is increasing awareness of the heterogeneity with which patients can present, which can lead to significant delays in recognition. Data from the Canadian PNH Registry are presented to demonstrate the variety of presenting symptoms. In Canada, geography precludes consolidation of care to just a few centers, so management is distributed across academic hospitals, linked together as the Canadian PNH Network. The Network over the last several years has developed educational programs and clinical checklists and has worked to standardize access to diagnostics across the country. Herein, we address some of the common diagnostic and therapeutic challenges faced by PNH physicians and give our recommendations. Gaps in knowledge are also addressed, and where appropriate, consensus opinion is provided.

The effectiveness and safety of fixed low-dose prothrombin complex concentrates in patients requiring urgent reversal of warfarin.

BACKGROUND: A rapid method of reversal is required for patients on warfarin who suffer acute bleeding or require emergency surgery. Prothrombin complex concentrates (PCCs) have recently been recommended by the Canadian Blood Services for use at a fixed low dose of 1000 IU of Factor (F)IX activity. The main goal of this study was to investigate both the effectiveness and the safety of fixed low-dose PCCs. STUDY DESIGN AND METHODS: We retrospectively reviewed charts from 103 patients who received PCCs for reversal of warfarin therapy. RESULTS: A total of 103 patients were treated with PCC at a single fixed dose of 1000 IU of F IX activity. Fifty patients (48.5%) had a final international normalized ratio (INR) response of not more than 1.5 and an additional 45 patients (43.7%) had a final INR response between 1.6 and 2.0. However, 86 patients (83.5%) had an excellent clinical response consisting of control of bleeding without the requirement of additional measures. In a multivariable model, patients who received fresh-frozen plasma and patients who were given doses greater than 1000 IU of PCC were both identified as predictors of a poor clinical response (odds ratio [OR] 3.48, 95% confidence interval [CI] 0.76-15.89, p = 0.11; and OR 10.8, 95% CI 2.08-56.28, 95% CI, p = 0.005, respectively). There were five adverse events up to 30 days after PCC use. CONCLUSION: At a fixed dose of 1000 IU of F IX activity, PCC seems to be effective and safe but randomized controlled trials, specifically examining different doses of PCC, are required to confirm the above observations.

Molecular targeting of the oncogene eIF4E in acute myeloid leukemia (AML): a proof-of-principle clinical trial with ribavirin.

The eukaryotic translation initiation factor eIF4E is elevated in 30% of malignancies including M4/M5 subtypes of acute myeloid leukemia (AML). The oncogenic potential of eIF4E arises from its ability to bind the 7-methyl guanosine (m(7)G) cap on mRNAs, thereby selectively enhancing eIF4E-dependent nuclear mRNA export and translation. We tested the clinical efficacy of targeting eIF4E in M4/M5 AML patients with a physical mimic of the m(7)G cap, ribavirin. Among 11 evaluable patients there were 1 complete remission (CR), 2 partial remissions (PRs), 2 blast responses (BRs), 4 stable diseases (SDs), and 2 progressive diseases (PDs). Ribavirin-induced relocalization of nuclear eIF4E to the cytoplasm and reduction of eIF4E levels were associated with clinical response. Lack of response or relapse coincided with continued or renewed nuclear localization of eIF4E. This first clinical study to target eIF4E in human malignancy demonstrates clinical activity and associated molecular responses in leukemic blasts. This trial is registered at ClinicalTrials.gov (NCT00559091).

Severe Cystic Echinococcosis-Associated Immune Thrombocytopenic Purpura: A Case Report.

We present a case of immune thrombocytopenic purpura (ITP), which leads to the diagnosis of severe cystic echinococcosis. Our patient presented with platelets of 5 × 109/L, and investigations uncovered multiple large echinococcal hepatic cysts, the largest of which measured 19.4 × 15 × 12 cm, and peritoneal implants. While initially refractory to prednisone and immunoglobulins, the ITP responded to dexamethasone. The echinococcosis was treated with albendazole followed by surgical resection of all lesions. Our patient's disease course has evolved favorable since his initial treatment with an isolated episode of recurrent thrombocytopenia 2 years later, and has remained in remission for the past 2 years. While a causal association between echinococcosis and ITP cannot be confirmed, this case is a reminder of the importance of remaining inquisitive for atypical potential triggers of ITP. We also present a review of the limited literature on the association of parasitic infections and ITP.

Common clonal origin of chronic myelomonocytic leukemia and B-cell acute lymphoblastic leukemia in a patient with a germline CHEK2 variant.

Hematological malignancies are broadly divided into myeloid and lymphoid neoplasms, reflecting the two major cellular lineages of the hematopoietic system. It is generally rare for hematological malignancies to spontaneously progress with a switch from myeloid to lymphoid lineage. We describe the exceptional case of a patient who sequentially developed myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), and B-cell acute lymphoblastic leukemia (B-ALL), as well as our investigation into the underlying pathogenesis. Using whole-exome sequencing (WES) performed on sorted CMML and B-ALL cell fractions, we identified both common and unique potential driver mutations, suggesting a branching clonal evolution giving rise to both diseases. Interestingly, we also identified a germline variant in the cancer susceptibility gene CHEK2 We validated that this variant (c.475T > C; p.Y159H), located in the forkhead-associated (FHA) domain, impairs its capacity to bind BRCA1 in cellulo. This unique case provides novel insight into the genetics of complex hematological diseases and highlights the possibility that such patients may carry inherited predispositions.

IND.216: a phase II study of buparlisib and associated biomarkers, raptor and p70S6K, in patients with relapsed and refractory chronic lymphocytic leukemia.

Buparlisib is an orally available pan-Class I PI3K inhibitor, that is more potent than idelalisib in vitro. Its distinct toxicities include hyperglycemia, hypertension, and mood disturbance. IND216 is a single arm phase II trial of buparlisib in Relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL). Fourteen patients were enrolled, 13 were evaluable for response and toxicity. Six of 13 patients had a partial response (46%) with a median duration of response of 15.5 months, all 11 patients with tumor assessment experienced tumor shrinkage. The most common adverse events (≥15%) were hyperglycemia, fatigue, anxiety, and gastrointestinal toxicities; all were < grade 3 except for fatigue. Three patients stopped therapy for alterations in mood. Lower levels of raptor were significantly associated with greater tumor shrinkage, suggesting that raptor could be a biomarker for response. This requires further validation in a larger CLL patient cohort. The clinical activity of buparlisib is comparable to other phosphatidylinositol-3-kinase inhibitors, with a different toxicity profile.Novelty and impactBuparlisib, an oral, pan PI3 kinase inhibitor, is associated with a 46% partial response rate among patients with relapse chronic lymphocytic leukemia (CLL). This is a similar clinical activity to other phosphatidylinositol-3-kinase inhibitors tested. However, buparlisib has a distinct toxicity profile, characterized by hyperglycemia, hypertension, and mood alteration. In agreement with our previous preclinical study, our results suggest that basal raptor expression in CLL correlates with clinical response to buparlisib.

Usefulness of frailty markers in the assessment of the health and functional status of older cancer patients referred for chemotherapy: a pilot study.

BACKGROUND: Older cancer patients seen in an oncology clinic seem to be healthier and less disabled than traditional geriatric patients. Choosing the most sensitive tools to assess their health status is a major issue. This cross-sectional study explores the usefulness of frailty markers in detecting vulnerability in older cancer patients. METHODS: The study included cancer patients >or=70 years old referred to an oncology clinic for chemotherapy. Information on comorbidities, disability in instrumental activities of daily living (IADL) and activities of daily living (ADL), and seven frailty markers (nutrition, mobility, strength, energy, physical activity, mood, and cognition) was collected. Patients were classified into four hierarchical groups: 1- No frailty markers, IADL, or ADL disability; 2- Presence of frailty markers without IADL or ADL disability; 3- IADL disability without ADL disability; 4- ADL disability. RESULTS: Among the 50 patients assessed, 6 (12.0%) were classified into Group 1, 21 (42.0%) into Group 2, 15 (30.0%) into Group 3, and 8 (16.0%) into Group 4. In Group 2, 7 patients (33.3 %) had one frailty marker, and 14 (66.7%) had two or more. The most prevalent of the frailty markers were nutrition, mobility, and physical activity. CONCLUSION: The assessment of seven frailty markers allowed the detection of potential vulnerability among 42% of older cancer patients that would not have been detected through an assessment of IADL and ADL disability alone. A longitudinal study is needed to determine whether the use of frailty markers can better characterize the older cancer population and predict adverse outcomes due to cancer treatment.

Refractory IgG Warm Autoimmune Hemolytic Anemia Treated with Eculizumab: A Novel Application of Anticomplement Therapy.

Warm autoimmune hemolytic anemia (wAIHA) is the most common form of AIHA, with corticosteroids in first-line treatment resulting in a 60-80% response rate. Atypical wAIHA and IgG plus complement mediated disease have a higher treatment failure rate and higher recurrence rate. We report a case of severe wAIHA secondary to Waldenström macroglobulinemia with life threatening intravascular hemolysis refractory to prednisone, rituximab, splenectomy, and plasmapheresis. A four-week treatment of eculizumab in this heavily pretreated patient resulted in a sustained increase in hemoglobin and transfusion independence, suggesting a role for complement inhibition in refractory wAIHA.

A phase I/II study of sorafenib in combination with low dose cytarabine in elderly patients with acute myeloid leukemia or high-risk myelodysplastic syndrome from the National Cancer Institute of Canada Clinical Trials Group: trial IND.186.

Sorafenib is active in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). The National Cancer Institute of Canada (NCIC) Clinical Trials Group initiated a phase I/II study of the combination of sorafenib with cytarabine in older patients with AML or high-risk MDS who were unsuitable for intensive chemotherapy. FLT3 mutational status was determined in all patients. Twenty-one patients were enrolled (four MDS, 17 AML) with a median age of 77 years. The recommended phase II dose (RP2D) was cytarabine 10 mg bid days 1-10 and sorafenib 600 mg/day days 2-28. Dose-limiting toxicities were fatigue, sepsis and skin rash. Of 15 evaluable patients treated at the RP2D, two patients responded. The overall response rate for eligible patients was 10%. FLT3 mutations were found in only three patients. We conclude that this combination of sorafenib and cytarabine has limited activity in this unselected cohort of elderly patients with AML/MDS in which FLT3 mutations seemed underrepresented.

A phase I study of imatinib mesylate in combination with chlorambucil in previously treated chronic lymphocytic leukemia patients.

PURPOSE: The tyrosine kinase inhibitor, imatinib, has the potential to indirectly inhibit DNA repair. This mechanism of action has been shown to mediate sensitization to chlorambucil in chronic lymphocytic leukemia (CLL). To evaluate this effect in vivo, we performed a phase I study of chlorambucil combined with imatinib in relapsed CLL patients. METHODS: The three dose levels studied included imatinib at 300, 400, or 600 mg/day. Imatinib was given on days 1-10, and chlorambucil (8 mg/m(2) daily) was given on days 3-7 of a 28-day cycle (up to 6 cycles). RESULTS: Eleven patients participated in this study. Low-grade gastrointestinal toxicities were observed in a dose-dependent manner. Forty-five percent of patients responded (two unconfirmed CRs and three PRs). Two responding patients were fludarabine refractory. The in vitro IC(50) of chlorambucil alone or in the presence of 5 µM imatinib in CLL lymphocytes correlated with the decrease in lymphocyte counts on day 15. Imatinib plasma concentrations achieved in patients were in the range of those effective in in vitro sensitization studies. CONCLUSION: The combination of chlorambucil and imatinib in patients with previously treated CLL was well tolerated and showed evidence of clinical efficacy. Based on our results, we recommend the 400 mg daily dose of imatinib on days 1-10 with 8 mg/m(3) chlorambucil on days 3-7 every 28 days as the phase II dose. This represents the first clinical trial examining the potential synergy between a tyrosine kinase inhibitor and a conventional alkylating agent for the treatment of CLL.