A phase I, open-label, dose-escalation, multicenter study of the JAK2 inhibitor NS-018 in patients with myelofibrosis

NS-018 is a Janus-activated kinase 2 (JAK2)-selective inhibitor, targeting the JAK–signal transducer and activator of transcription (STAT) pathway that is deregulated in myelofibrosis. In this phase I, dose-escalation portion of a phase I/II study, patients with myelofibrosis received oral NS-018 in continuous 28-day cycles. The primary study objective was to evaluate safety, tolerability and clinically active dose of NS-018. Forty-eight patients were treated; 23 (48%) had previously received a JAK inhibitor (JAKi). The most common drug-related adverse events were thrombocytopenia (27%)/anemia (15%) for hematologic events, and dizziness (23%)/nausea (19%) for non-hematologic events. Once daily NS-018 at 300 mg was chosen as the phase II study dose based on improved tolerability compared with higher doses. A ⩾50% reduction in palpable spleen size was achieved in 56% of patients (47% of patients with prior JAKi treatment), and improvements were observed in myelofibrosis-associated symptoms. Bone marrow fibrosis grade (local assessment) improved from baseline in 11/30 evaluable patients (37%) after 3 cycles of NS-018. JAK2 allele burden was largely unchanged. Changes in cytokine/protein levels were noted after 4 weeks of treatment. NS-018 reached peak plasma concentration in 1–2 h and did not accumulate with multiple dosing. NS-018 will be assessed in patients with previous JAKi exposure in the phase II portion.

Ruxolitinib: long-term management of patients with myelofibrosis and future directions in the treatment of myeloproliferative neoplasms

Considerable clinical experience regarding the long-term efficacy and safety of ruxolitinib has been gathered since the drug was approved in the USA for patients with intermediate or high-risk myelofibrosis (MF) in November 2011. Findings from the pivotal phase 3 COMFORT studies showed that ruxolitinib-associated reductions in MF-related splenomegaly and symptom burden occur rapidly and in the majority of patients. Two- and 3-year follow-up data further suggest that the benefits of ruxolitinib are durable and associated with a survival advantage compared with conventional therapies. However, careful management of treatment-related thrombocytopenia and anemia with dose modifications and supportive care is critical to allow chronic therapy. Based on preliminary evidence, ruxolitinib also allows spleen size and symptom reduction before allogeneic stem cell transplantation without negative effect on engraftment or outcomes. In recent studies, ruxolitinib provided effective management of hematologic parameters and symptoms in patients with polycythemia vera refractory to or intolerant of hydroxyurea.

Phase I/II multicenter study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of AZD4877 in patients with refractory acute myeloid leukemia

Eg5 (kinesin spindle protein) is a microtubule motor protein, essential for centrosome separation during mitosis. This Phase I/II, open-label, multicenter, two-part study investigated AZD4877, a potent Eg5 inhibitor, in patients with acute myeloid leukemia. Primary objectives were to determine the maximum tolerated dose (MTD) (part A), assess efficacy (part B) and determine the pharmacokinetic profile (parts A and B). Secondary objectives included assessment of safety and tolerability. AZD4877 was administered at a range of doses (2, 4, 7, 10, 13, 16 and 18 mg/day) as a 1-hour intravenous infusion on three consecutive days of a continuous 2-week schedule. The MTD in part A was defined as 16 mg/day based on dose-limiting stomatitis at 16 and 18 mg/day, hyperbilirubinemia at 16 mg/day and palmar-plantar erythrodysesthesia syndrome at 18 mg/day. Systemic exposure to AZD4877 generally increased with increasing dose whereas half-life was not dose dependent. No evaluable patients experienced a complete remission (CR) or CR with incomplete blood count recovery (CRi), demonstrating no evidence of AZD4877 efficacy in this population. Evidence of monoasters in all but the 4 mg/day dose group provided proof of mechanism for AZD4877. This study was terminated due to lack of efficacy. (ClinicalTrials.gov identifier NCT00486265).

Mutations with epigenetic effects in myeloproliferative neoplasms and recent progress in treatment: Proceedings from the 5th International Post-ASH Symposium

Immediately following the 2010 annual American Society of Hematology (ASH) meeting, the 5th International Post-ASH Symposium on Chronic Myelogenous Leukemia and BCR-ABL1-Negative Myeloproliferative Neoplasms (MPNs) took place on 7–8 December 2010 in Orlando, Florida, USA. During this meeting, the most recent advances in laboratory research and clinical practice, including those that were presented at the 2010 ASH meeting, were discussed among recognized authorities in the field. The current paper summarizes the proceedings of this meeting in BCR-ABL1-negative MPN. We provide a detailed overview of new mutations with putative epigenetic effects (TET oncogene family member 2 (TET2), additional sex comb-like 1 (ASXL1), isocitrate dehydrogenase (IDH) and enhancer of zeste homolog 2 (EZH2)) and an update on treatment with Janus kinase (JAK) inhibitors, pomalidomide, everolimus, interferon-α, midostaurin and cladribine. In addition, the new ‘Dynamic International Prognostic Scoring System (DIPSS)-plus' prognostic model for primary myelofibrosis (PMF) and the clinical relevance of distinguishing essential thrombocythemia from prefibrotic PMF are discussed.

Phase II trial of decitabine in myelofibrosis with myeloid metaplasia

7088

Background: DNA hypermethylation of promoter-specific CpG islands has been implicated in the pathogenesis and progression of disease in MMM. We are evaluating Decitabine, a DNA methyltransferase inhibitor in patients (pts) with MMM. Methods: This is a single stage Phase II trial: planned accrual of 20 pts. Pts had to have MMM with anemia and/or splenomegaly. Decitabine is given subcutaneously (SQ) at a dose of 0.3 mg/kg/d on days 1–5, and days 8–12; cycles are repeated every 6 weeks, in the absence of dose limiting toxicities. Response is determined every 12 weeks as an improvement in cytopenias and/or splenomegaly. CD34+ cells are measured by flow cytometry in peripheral blood at baseline, and at days 5 and 12 of therapy; elevated levels are associated with advanced stage and evolution to blast phase in MMM. Results: Pt characteristics: M/F: 6/4, median age 67 (range 42–89), median absolute CD34+ cell count 116 × 106/L (11–4,959), Dupriez score of 2, 1 and 0 in 50%, 30% and 20% respectively. Median number of cycles administered: 3 (range 1- 9). Median WBC and platelet (plt) count: 5.2 K/uL (1.5–29), and 171 K/uL (47–465 K/uL); 5 pts were red cell transfusion dependent. Grade 4 neutropenia (ANC) occurred in all pts, and grade 3/4 plts in 6 pts. 7 pts have developed febrile neutropenia. Grade 3–4 non-hematologic toxicities include a variceal bleed in a patient with baseline portal hypertension and a splenic infarct occurring in another pt. 7 pts are evaluable for response: 3 pts have responded including 1 pt with a CR (normalization of blood counts and transfusion independence), and 1 pt with a PR (Hb increase of > 2 g/dL). A third pt in the blast phase of the disease had a hematological improvement as evidenced by a normalization in plts (from 62 K/uL to 219 K/uL) associated with a significant decrease (from 2.58 K/uL to 0.03 K/uL) in circulating blasts. The other 4 pts have had stable disease. There was a reduction in CD34+ levels: mean decrease of approximately 75% at day 12 of therapy (p<0.0001). Conclusions: Low dose SQ decitabine is feasible in MMM and is associated with a significant decrease in CD34+ cells. There is preliminary evidence of clinical activity. Myelosupression is significant, though reversible and requires close monitoring. These findings must be validated in a larger group of pts. Sponsored by NCI grant NO1-CM-62201

No significant financial relationships to disclose.

A phase I study of MGCD0103 given as a twice weekly oral dose in patients with advanced leukemias or myelodysplastic syndromes (MDS)

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Background: Small molecule inhibitors of histone deacetylase (HDAC) have emerged as novel anticancer agents. MGCD0103 is an oral isotype selective small molecule inhibitor of HDAC. Methods: Eligible patients had relapsed/refractory (RR) AML or MDS (or newly diagnosed disease in patients >60 yrs, ineligible for induction chemotherapy); RR ALL; RR CML. MGCD0103 was administered 2x/weekly for 3 weeks, with no recovery period between cycles. Patients with stable disease or better were eligible to continue therapy indefinitely. Results: Patients have been treated at 4 dose levels: 40, 53, 66 and 83 mg/m2/day, including 19 enrolled patients with the following demographics: M:F = 15:4, median age (range) = 75 (52–83), ECOG 0:1:2 = 5:12:2, diagnosis of RR MDS= 7, RR AML or RR ALL=8: untreated AML or MDS = 4. Cytogenetics (n=12): Diploid = 3, Complex = 4, Del 7 = 3, Del 12 = 1, Del Y = 1. Nineteen patients are evaluable for safety. A total of 38 cycles have been administered with a median of 2 per patient (range, 1–6); 13 patients have completed =2 cycles. One patient experienced grade 3 fatigue at 53 mg/m2 and 2 patients had grade 3 weakness/fatigue at 83 mg/m2 (exceeded the Maximum Tolerated Dose [MTD]) Non-dose-limiting toxicities included lower grade fatigue, diarrhea, and nausea. Plasma PK in 14 patients revealed t 1/2 of 7–12 hr, tmax 0.6- 1 hr, and a dose proportional average Cmax of 155 ng/mL at 40 mg/m2 and 225 ng/mL at 53 mg/m2. Significant inhibition of whole cell total HDAC activity within PBMC was observed in a majority of patients, at all dosing levels. Four patients have experienced stable disease. Conclusions: MGCD0103 has been well-tolerated in patients with advanced leukemias or MDS. MTD has been reached, and the recommended phase II 2x/week dose is being confirmed. At all dose levels, significant HDAC inhibition was observed.

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Fludarabine, melphalan, and alemtuzumab conditioning in adults with standard-risk advanced acute myeloid leukemia and myelodysplastic syndrome

PURPOSE

This prospective phase II study evaluated toxicity, relapse rate, progression-free survival, and overall survival after allogeneic transplantation and conditioning with fludarabine, melphalan, and alemtuzumab in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

PATIENTS AND METHODS

Fifty-two consecutive adults with AML and MDS were enrolled onto the study. Median age was 52 years (range, 17 to 71 years) and the majority of patients had high-risk disease, comorbidities, and/or modest reduction in performance status. Fifty-six percent of patients had unrelated or mismatched related donors.

RESULTS

After a median follow-up of 18 months (range, 2 to 34 months), 1-year survival was 48% (95% CI, 34% to 61%), progression-free survival was 38% (95% CI, 25% to 52%), relapse rate was 27% (95% CI, 15% to 40%), and treatment-related mortality was 33% (95% CI, 20% to 46%). The cumulative probability of extensive chronic graft-versus-host disease (GVHD) was only 18% (95% CI, 8% to 40%); extensive chronic GVHD was only observed in recipients of unrelated donor transplants. Performance score and disease status were the major predictors of outcome. High-risk disease (ie, active AML or MDS with > 5% blasts) or even modest decreases in performance status were associated with poor outcomes. Patients with standard-risk leukemia (first or second complete remission) or MDS (< 5% blasts) had excellent outcomes despite unfavorable disease characteristics.

CONCLUSION

Fludarabine and melphalan combined with in vivo alemtuzumab is a promising transplantation regimen for patients with AML or MDS and low tumor burden. For patients with active disease, this regimen provides at best modest palliation. Despite a low incidence of GVHD, transplantation is still associated with considerable nonrelapse mortality in patients with decreased performance status.