Phase 2 study of add-on parsaclisib for patients with myelofibrosis and suboptimal response to ruxolitinib: final results.

ABSTRACT: Ruxolitinib reduces spleen volume, improves symptoms, and increases survival in patients with intermediate- or high-risk myelofibrosis. However, suboptimal response may occur, potentially because of signaling via the phosphoinositide 3-kinase (PI3K)/protein kinase B pathway. This phase 2 study evaluated dosing, efficacy, and safety of add-on PI3Kδ inhibitor parsaclisib for patients with primary or secondary myelofibrosis with suboptimal response to ruxolitinib. Eligible patients remained on a stable ruxolitinib dose and received add-on parsaclisib 10 or 20 mg, once daily for 8 weeks, and once weekly thereafter (daily-to-weekly dosing; n = 32); or parsaclisib 5 or 20 mg, once daily for 8 weeks, then 5 mg once daily thereafter (all-daily dosing; n = 42). Proportion of patients achieving a ≥10% decrease in spleen volume at 12 weeks was 28% for daily-to-weekly dosing and 59.5% for all-daily dosing. Proportions of patients achieving ≥50% decrease at week 12 in Myelofibrosis Symptom Assessment Form and Myeloproliferative Neoplasms Symptom Assessment Form symptom scores were 14% and 18% for daily-to-weekly dosing, and 28% and 32% for all-daily dosing, respectively. Most common nonhematologic treatment-emergent adverse events were nausea (23%), diarrhea (22%), abdominal pain and fatigue (each 19%), and cough and dyspnea (each 18%). New-onset grade 3 and 4 thrombocytopenia were observed in 19% of patients, each dosed daily-to-weekly, and in 26% and 7% of patients dosed all-daily, respectively, managed with dose interruptions. Hemoglobin levels remained steady. The addition of parsaclisib to stable-dose ruxolitinib can reduce splenomegaly and improve symptoms, with manageable toxicity in patients with myelofibrosis with suboptimal response to ruxolitinib. This trial was registered at www.clinicaltrials.gov as #NCT02718300.

A randomized phase 3 trial of interferon-α vs hydroxyurea in polycythemia vera and essential thrombocythemia.

The goal of therapy for patients with essential thrombocythemia (ET) and polycythemia vera (PV) is to reduce thrombotic events by normalizing blood counts. Hydroxyurea (HU) and interferon-α (IFN-α) are the most frequently used cytoreductive options for patients with ET and PV at high risk for vascular complications. Myeloproliferative Disorders Research Consortium 112 was an investigator-initiated, phase 3 trial comparing HU to pegylated IFN-α (PEG) in treatment-naïve, high-risk patients with ET/PV. The primary endpoint was complete response (CR) rate at 12 months. A total of 168 patients were treated for a median of 81.0 weeks. CR for HU was 37% and 35% for PEG (P = .80) at 12 months. At 24 to 36 months, CR was 20% to 17% for HU and 29% to 33% for PEG. PEG led to a greater reduction in JAK2V617F at 24 months, but histopathologic responses were more frequent with HU. Thrombotic events and disease progression were infrequent in both arms, whereas grade 3/4 adverse events were more frequent with PEG (46% vs 28%). At 12 months of treatment, there was no significant difference in CR rates between HU and PEG. This study indicates that PEG and HU are both effective treatments for PV and ET. With longer treatment, PEG was more effective in normalizing blood counts and reducing driver mutation burden, whereas HU produced more histopathologic responses. Despite these differences, both agents did not differ in limiting thrombotic events and disease progression in high-risk patients with ET/PV. This trial was registered at www.clinicaltrials.gov as #NCT01259856.

Safety and efficacy of avapritinib in advanced systemic mastocytosis: the phase 1 EXPLORER trial.

Advanced systemic mastocytosis (AdvSM) is a rare hematologic neoplasm driven by the KIT D816V mutation and associated with poor survival. This phase 1 study ( NCT02561988 ) evaluated avapritinib (BLU-285), a selective KIT D816V inhibitor, in patients with AdvSM. The primary endpoints were the maximum tolerated dose, recommended phase 2 dose and safety of avapritinib. Secondary endpoints included overall response rate and changes in measures of mast cell burden. Avapritinib was evaluated at doses of 30-400 mg once daily in 86 patients, 69 with centrally confirmed AdvSM. Maximum tolerated dose was not reached, and 200 mg and 300 mg daily were studied in dose-expansion cohorts. The most frequent adverse events observed were periorbital edema (69%), anemia (55%), diarrhea (45%), thrombocytopenia (44%) and nausea (44%). Intracranial bleeding occurred in 13% overall, but in only 1% of patients without severe thrombocytopenia (platelets <50 × 109/l). In 53 response-evaluable patients, the overall response rate was 75%. The complete remission rate was 36%. Avapritinib elicited ≥50% reductions in marrow mast cells and serum tryptase in 92% and 99% of patients, respectively. Avapritinib induced deep and durable responses, including molecular remission of KIT D816V in patients with AdvSM, and was well tolerated at the recommended phase 2 dose of 200 mg daily.

Comanagement Strategy Between Academic Institutions and Community Practices to Reduce Induction Mortality in Acute Promyelocytic Leukemia.

PURPOSE: Acute promyelocytic leukemia (APL) is a curable leukemia with > 90% survival in clinical trials. Population-based studies from Sweden and US SEER data have shown long-term survival rates of 62% and 65.7%, with the lower rate being from a higher percentage of early deaths. METHODS: In this prospective, multicenter trial, we developed a simplified algorithm that focused on prevention and early treatment of the three main causes of death: bleeding, differentiation syndrome, and infection. All patients with a diagnosis of APL were included. The initial 6 months were spent educating oncologists about early deaths in APL. At the time of suspicion of an APL, an expert was contacted. The algorithm was made available followed by discussion of the treatment plan. Communication between expert and treating physician was frequent in the first 2 weeks, during which time most deaths take place. RESULTS: Between September 2013 and April 2016, 120 patients enrolled in the study from 32 hospitals. The median age was 52.5 years, with 39% > 60 years and 25% with an age-adjusted Charlson comorbidity index > 4. Sixty-three percent of patients were managed at community centers. Two patients did not meet the criteria for analysis, and of 118 evaluable patients, 10 died, with an early mortality rate of 8.5%. With a median follow-up of 27.3 months, the overall survival was 84.5%. CONCLUSION: Induction mortality can be decreased and population-wide survival improved in APL with the use of standardized treatment guidelines. Support from experts who have more experience with induction therapy is crucial and helps to improve the outcomes.

Real-World Outcomes of Ruxolitinib Treatment for Polycythemia Vera.

INTRODUCTION: Ruxolitinib is approved for the treatment of polycythemia vera (PV) with hydroxyurea resistance or intolerance. Approval was based on the phase III RESPONSE trial, which demonstrated efficacy in a highly selected patient population. MATERIALS AND METHODS: To characterize the tolerability and outcomes of ruxolitinib outside of a clinical trial, we performed a multi-center retrospective analysis of patients with PV treated with ruxolitinib at 11 participating sites across the United States. Outcomes of interest included change in phlebotomy requirements after starting ruxolitinib and spleen response, as these were included in the primary composite outcome in the RESPONSE trial. RESULTS: One hundred twenty-six patients met eligibility criteria, and the median duration of follow-up was 22.4 months (range, 0-63.0 months). At 32 weeks after starting ruxolitinib, the percentage of patients who received at least 1 phlebotomy was significantly decreased compared with before ruxolitinib (37% vs. 56%; relative risk [RR], 0.66; 95% confidence interval [CI], 0.52-0.84; P < .001). Phlebotomy requirements were similarly decreased in patients who had received at least 3 phlebotomies prior to ruxolitinib initiation (28% vs. 17%; RR, 1.65; 95% CI, 1.13-2.40; P < .01). Resolution of palpable splenomegaly was also documented (48% vs. 20%; RR, 2.45; 95% CI, 1.70-3.53; P < .0001). A total of 9.5% of patients discontinued ruxolitinib owing to treatment-emergent adverse events, and 81.7% of patients were receiving ruxolitinib at last known follow-up. CONCLUSION: These real-world results are similar to those reported from the RESPONSE trial, although additional follow-up is necessary to assess long-term outcomes and potential for late-onset toxicity.

Outcomes of Chronic Phase Chronic Myeloid Leukemia after Treatment with Multiple Tyrosine Kinase Inhibitors.

We sought to evaluate the outcomes of chronic phase (CP) chronic myeloid leukemia (CML) in an era where five tyrosine kinase inhibitors (TKIs) are commercially available for the treatment of CML. Records of patients diagnosed with CP CML, treated with TKIs and referred to our center were reviewed. Between January 2005 and April 2016, 206 patients were followed for a median of 48.8 (1.4-190.1) months. A total of 76 (37%) patients received one TKI, 73 (35%) received two TKIs and 57 (28%) were exposed to >3 TKIs (3 TKIs, n = 33; 4 TKIs, n = 17; 5 TKIs, n = 7). Nineteen (9.2%) patients progressed to advanced phases of CML (accelerated phase, n = 6; myeloid blastic phase, n = 4; lymphoid blastic phase, n = 9). One third (n = 69) achieved complete molecular response (CMR) at first-line treatment. An additional 55 patients achieved CMR after second-line treatment. Twenty-five patients (12.1%) attempted TKI discontinuation and 14 (6.8%) stopped TKIs for a median of 6.3 months (range 1-53.4). The 10-year progression-free survival and overall survival (OS) rates were 81% and 87%, respectively. OS after 10-years, based on TKI exposure, was 100% (1 TKI), 82% (2 TKIs), 87% (3 TKIs), 75% (4 TKIs) and 55% (5 TKIs). The best OS was observed in patients tolerating and responding to first line TKI, but multiple TKIs led patients to gain treatment-free remission.

Pegylated interferon alfa-2a for polycythemia vera or essential thrombocythemia resistant or intolerant to hydroxyurea.

Prior studies have reported high response rates with recombinant interferon-α (rIFN-α) therapy in patients with essential thrombocythemia (ET) and polycythemia vera (PV). To further define the role of rIFN-α, we investigated the outcomes of pegylated-rIFN-α2a (PEG) therapy in ET and PV patients previously treated with hydroxyurea (HU). The Myeloproliferative Disorders Research Consortium (MPD-RC)-111 study was an investigator-initiated, international, multicenter, phase 2 trial evaluating the ability of PEG therapy to induce complete (CR) and partial (PR) hematologic responses in patients with high-risk ET or PV who were either refractory or intolerant to HU. The study included 65 patients with ET and 50 patients with PV. The overall response rates (ORRs; CR/PR) at 12 months were 69.2% (43.1% and 26.2%) in ET patients and 60% (22% and 38%) in PV patients. CR rates were higher in CALR-mutated ET patients (56.5% vs 28.0%; P = .01), compared with those in subjects lacking a CALR mutation. The median absolute reduction in JAK2V617F variant allele fraction was -6% (range, -84% to 47%) in patients achieving a CR vs +4% (range, -18% to 56%) in patients with PR or nonresponse (NR). Therapy was associated with a significant rate of adverse events (AEs); most were manageable, and PEG discontinuation related to AEs occurred in only 13.9% of subjects. We conclude that PEG is an effective therapy for patients with ET or PV who were previously refractory and/or intolerant of HU. This trial was registered at www.clinicaltrials.gov as #NCT01259856.

Ruxolitinib: a steroid sparing agent in chronic graft-versus-host disease.

Inhibition of the Janus-associated kinases (JAK) with ruxolitinib (RUX) reduces graft-versus-host disease (GVHD) in preclinical and clinical models. In total 19 allograft recipients with moderate/severe steroid-dependent chronic GVHD received RUX as ≥2nd line salvage. RUX was well tolerated, and led to complete/partial resolution of oral (92/7%), cutaneous (82/0%), hepatic (71/28%), gastro-intestinal (75/17%), musculoskeletal (33/67%), pulmonary (0/80%), scleroderma (0/75%), vaginal (0/75%), and ocular (0/100%) chronic GVHD. Overall 18 achieved partial response and 1 complete response according to NIH Consensus Criteria. Responses occurred early and were sustained which enabled discontinuation (68%) or reduction of steroids to physiologic doses (21%). We conclude that RUX is an effective steroid-sparing agent in chronic GVHD.

Momelotinib versus best available therapy in patients with myelofibrosis previously treated with ruxolitinib (SIMPLIFY 2): a randomised, open-label, phase 3 trial.

BACKGROUND: The Janus kinase (JAK) inhibitor ruxolitinib is the only approved therapy for patients with symptomatic myelofibrosis. After ruxolitinib failure, however, there are few therapeutic options. We assessed the efficacy and safety of momelotinib, a JAK 1 and JAK 2 inhibitor, versus best available therapy (BAT) in patients with myelofibrosis who had suboptimal responses or haematological toxic effects with ruxolitinib. METHODS: In this randomised, phase 3, open-label trial, patients were screened for eligibility from 52 clinical centres in Canada, France, Germany, Israel, Italy, Spain, the UK, and the USA. Patients who had myelofibrosis and previous ruxolitinib treatment for at least 28 days who either required red blood cell transfusions while on ruxolitinib or ruxolitinib dose reduction to less than 20 mg twice a day with at least one of grade 3 thrombocytopenia, anaemia, or bleeding at grade 3 or worse, with palpable spleen of at least 5 cm and without grade 2 or greater peripheral neuropathy were included in the study. Patients were randomly assigned (2:1) to either 24 weeks of open-label momelotinib 200 mg once a day or BAT (which could include ruxolitinib, chemotherapy, steroids, no treatment, or other standard interventions), after which all patients could receive extended momelotinib treatment. Patients were randomly assigned to treatment by an interactive web response system and the randomisation was stratified by transfusion dependence and by baseline total symptom score (TSS). Results were analysed on an intention-to-treat basis. The primary endpoint was a reduction by at least 35% in the spleen volume at 24 weeks compared with baseline. Safety analyses included adverse event monitoring. The trial is registered with ClinicalTrials.gov, number NCT02101268. FINDINGS: Between June 19, 2014, and July 28, 2016, 156 patients were recruited to the study; 104 received momelotinib and 52 received BAT. BAT was ruxolitinib in 46 (89%) of 52 patients. 73 (70%) of 104 patients in the momelotinib group and 40 (77%) of 52 patients in the BAT group completed the 24-week treatment phase. Seven (7%) of 104 patients in the momelotinib group and three (6%) of 52 in the BAT group had a reduction in the spleen volume by at least 35% compared with baseline (proportion difference [Cochran-Mantel-Haenszel method], 0·01; 95% CI -0·09 to 0·10), p=0·90). The most common grade 3 or worse adverse events were anaemia (14 [14%] of 104 in the momelotinib group vs seven [14%] of 52 in the BAT group), thrombocytopenia (seven [7%] vs three [6%]), and abdominal pain (one [1%] vs three [6%]). Peripheral neuropathy occurred in 11 (11%) of 104 patients receiving momelotinib (one of which was grade 3) and in no patients in the BAT group. Serious events were reported for 36 (35%) patients in the momelotinib group and 12 (23%) of patients in the BAT group. Deaths due to adverse events were reported for six patients (6%) receiving momelotinib (acute myeloid leukaemia [n=2], respiratory failure [n=2, with one considered possibly related to momelotinib], cardiac arrest [n=1, considered possibly related to momelotinib], and bacterial sepsis [n=1]); and four patients (8%) receiving BAT (lung adenocarcinoma [n=1], myelofibrosis [n=1], and sepsis [n=2]). INTERPRETATION: In patients with myelofibrosis previously treated with ruxolitinib, momelotinib was not superior to BAT for the reduction of spleen size by at least 35% compared with baseline. FUNDING: Gilead Sciences, Inc.

Outcomes of Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia Following an Elective Switch From Second-Generation Tyrosine Kinase Inhibitor to Imatinib.

The second-generation tyrosine kinase inhibitors (TKIs) (2G-TKIs) dasatinib (DAS) and nilotinib (NIL) yield faster responses in newly diagnosed chronic phase (CP) chronic myeloid leukemia (CML) as compared with imatinib (IM); however, long-term safety of these agents is a growing concern. We identified 20 patients with CP-CML diagnosed between August 2013 and October 2016 who initiated 2G-TKIs and were then switched after optimal response at 3 months to IM. Second-generation TKIs initiated were DAS (n = 15), NIL (n = 3), or both sequentially due to intolerance (n = 1). One other patient initiated therapy with ponatinib on trial. Response was assessed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) for BCR-ABL1 levels every 3 months and in patients with qRT-PCR values less than 10% at 3 months, IM was started at 400 mg/d. IM was well tolerated except in 2 patients who required dose-reduction and discontinuation due to grade 2 skin rash (1) and grade 2 anxiety (1). After initiation of IM therapy, the BCR-ABL1 qRT-PCR levels trended down as expected. At 12 months 16 (84.2%) of 19 evaluable patients showed a 3 log (major molecular remission) or better reduction in their PCR levels. In conclusion, this retrospective analysis shows that IM can be safely and effectively administered following optimal response to 2G-TKIs. A prospective trial exploring this approach is currently enrolling and will be needed to confirm the safety and efficacy of this therapeutic approach.

SIMPLIFY-1: A Phase III Randomized Trial of Momelotinib Versus Ruxolitinib in Janus Kinase Inhibitor-Naïve Patients With Myelofibrosis.

Purpose We evaluated the efficacy and safety of momelotinib, a potent and selective Janus kinase 1 and 2 inhibitor (JAKi), compared with ruxolitinib, in JAKi-naïve patients with myelofibrosis. Patients and Methods Patients (N = 432) with high risk or intermediate-2 risk or symptomatic intermediate-1 risk myelofibrosis were randomly assigned to receive 24 weeks of treatment with momelotinib 200 mg once daily or ruxolitinib 20 mg twice a day (or per label), after which all patients could receive open-label momelotinib. The primary end point was a ≥ 35% reduction in spleen volume at 24 weeks of therapy. Secondary end points were rates of symptom response and effects on RBC transfusion requirements. Results A ≥ 35% reduction in spleen volume at week 24 was achieved by a similar proportion of patients in both treatment arms: 26.5% of the momelotinib group and 29% of the ruxolitinib group (noninferior; P = .011). A ≥ 50% reduction in the total symptom score was observed in 28.4% and 42.2% of patients who received momelotinib and ruxolitinib, respectively, indicating that noninferiority was not met ( P = .98). Transfusion rate, transfusion independence, and transfusion dependence were improved with momelotinib (all with nominal P ≤ .019). The most common grade ≥ 3 hematologic abnormalities in either group were thrombocytopenia and anemia. Grade ≥ 3 infections occurred in 7% of patients who received momelotinib and 3% of patients who received ruxolitinib. Treatment-emergent peripheral neuropathy occurred in 10% of patients who received momelotinib (all grade ≤ 2) and 5% of patients who received ruxolitinib (all grade ≤ 3). Conclusion In JAKi-naïve patients with myelofibrosis, 24 weeks of momelotinib treatment was noninferior to ruxolitinib for spleen response but not for symptom response. Momelotinib treatment was associated with a reduced transfusion requirement.

Janus kinase-2 inhibitor fedratinib in patients with myelofibrosis previously treated with ruxolitinib (JAKARTA-2): a single-arm, open-label, non-randomised, phase 2, multicentre study.

BACKGROUND: Myelofibrosis is a chronic myeloproliferative neoplasm characterised by splenomegaly, cytopenias, bone marrow fibrosis, and debilitating symptoms including fatigue, weight loss, and bone pain. Mutations in Janus kinase-2 (JAK2) occur in approximately 50% of patients. The only approved JAK2 inhibitor for myelofibrosis is the dual JAK1 and JAK2 inhibitor, ruxolitinib. 58-71% of patients treated with ruxolitinib in clinical trials so far have not achieved the primary endpoint of 35% or more reduction in spleen volume from baseline assessed by MRI or CT. Furthermore, more than 50% of patients discontinue ruxolitinib treatment after 3-5 years. On the basis of this unmet need, we investigated the efficacy and safety of fedratinib, a JAK2-selective inhibitor, in patients with ruxolitinib-resistant or ruxolitinib-intolerant myelofibrosis. METHODS: This single-arm, open-label, non-randomised, phase 2, multicentre study, done at 31 sites in nine countries, enrolled adult patients with a current diagnosis of intermediate or high-risk primary myelofibrosis, post-polycythaemia vera myelofibrosis, or post-essential thrombocythaemia myelofibrosis, found to be ruxolitinib resistant or intolerant after at least 14 days of treatment. Other main inclusion criteria were palpable splenomegaly (≥5 cm below the left costal margin), Eastern Cooperative Oncology Group performance status of 2 or less, and life expectancy of 6 months or less. Patients received oral fedratinib at a starting dose of 400 mg once per day, for six consecutive 28-day cycles. The primary endpoint was spleen response (defined as the proportion of patients with a ≥35% reduction in spleen volume as determined by blinded CT and MRI at a central imaging laboratory). We did the primary analysis in the per-protocol population only (patients treated with fedratinib, for whom a baseline and at least one post-baseline spleen volume measurement was available) and the safety analysis in all patients receiving at least one dose of fedratinib. This trial was registered with ClinicalTrials.gov, number NCT01523171. FINDINGS: Between May 8, 2012, and Aug 29, 2013, 97 patients were enrolled and received at least one dose of fedratinib. Of 83 assessable patients, 46 (55%, 95% CI 44-66) achieved a spleen response. Common grade 3-4 adverse events included anaemia (37 [38%] of 97 patients) and thrombocytopenia (21 [22%] of 97), with 18 (19%) patients discontinuing due to adverse events. Seven (7%) patients died during the study, but none of the deaths was drug related. Suspected cases of Wernicke's encephalopathy in other fedratinib trials led to study termination. INTERPRETATION: This phase 2 study met its primary endpoint, suggesting that patients with ruxolitinib-resistant or ruxolitinib-intolerant myelofibrosis might achieve significant clinical benefit with fedratinib, albeit at the cost of some potential toxicity, which requires further evaluation. Fedratinib development in this setting is currently being assessed. FUNDING: Sanofi.

Long-term treatment with ruxolitinib for patients with myelofibrosis: 5-year update from the randomized, double-blind, placebo-controlled, phase 3 COMFORT-I trial.

BACKGROUND: The randomized, double-blind, placebo-controlled, phase 3 COMFORT-I trial evaluated the JAK1/JAK2 inhibitor ruxolitinib in patients with intermediate-2/high-risk myelofibrosis. The primary and planned 3-year analyses of COMFORT-I data demonstrated that ruxolitinib-the first myelofibrosis-approved therapy-reduced splenomegaly and prolonged overall survival versus placebo. Here, we present the final 5-year results. METHODS: Patients managed in Australia, Canada, and the USA were randomized centrally (interactive voice response system) 1:1 to oral ruxolitinib twice daily (15 or 20 mg per baseline platelet counts) or placebo. Investigators and patients were blinded to treatment. The secondary endpoints evaluated in this analysis were durability of a ≥35% reduction from baseline in spleen volume (spleen response) and overall survival, evaluated in the intent-to-treat population. Safety was evaluated in patients who received study treatment. RESULTS: Patients were randomized (September 2009-April 2010) to ruxolitinib (n = 155) or placebo (n = 154). At termination, 27.7% of ruxolitinib-randomized patients and 25.2% (28/111) who crossed over from placebo were on treatment; no patients remained on placebo. Patients randomized to ruxolitinib had a median spleen response duration of 168.3 weeks and prolonged median overall survival versus placebo (ruxolitinib group, not reached; placebo group, 200 weeks; HR, 0.69; 95% CI, 0.50-0.96; P = 0.025) despite the crossover to ruxolitinib. The ruxolitinib safety profile remained consistent with previous analyses. The most common new-onset all-grade nonhematologic adverse events starting <12 versus ≥48 months after ruxolitinib initiation were fatigue (29.0 vs 33.3%) and diarrhea (27.8 vs 14.6%). New-onset grade 3 or 4 anemia and thrombocytopenia both primarily occurred within the first 6 months, with no cases after 42 months. The most common treatment-emergent adverse event-related deaths in the ruxolitinib-randomized group were sepsis (2.6%), disease progression (1.9%), and pneumonia (1.9%). CONCLUSION: The final COMFORT-I results continue to support ruxolitinib as an effective treatment for patients with intermediate-2/high-risk MF. TRIAL REGISTRATION: ClinicalTrials.gov, NCT00952289.

Does the frequency of molecular monitoring after tyrosine kinase inhibitor discontinuation affect outcomes of patients with chronic myeloid leukemia?

BACKGROUND: To the authors' knowledge, the optimal frequency of monitoring after tyrosine kinase inhibitor (TKI) discontinuation in patients with chronic myeloid leukemia (CML) has not been established. Data regarding the discontinuation of second-generation TKIs used in first-line treatment or after the failure of first-line treatment with TKIs are limited. Herein, the authors report real-world experience with "reduced frequency" molecular monitoring in patients with CML in all phases who discontinued treatment with imatinib, dasatinib, or bosutinib. METHODS: The records of patients who discontinued TKIs were reviewed. Patients who discontinued TKIs were monitored prospectively on an intended schedule of monthly blood quantitative reverse transcriptase-polymerase chain reaction for BCR-ABL1 for 3 months, quarterly for 12 months, and every 6 months thereafter until loss of major molecular response (MMR). After loss of MMR, the TKI that previously was discontinued was reinitiated. RESULTS: Between January 2010 and September 2015, a total of 24 patients in chronic (21 patients), accelerated (2 patients), and lymphoid blast (1 patient) phase discontinued imatinib (16 patients), dasatinib (5 patients), or bosutinib (3 patients) used in the front-line treatment or beyond. Blood quantitative reverse transcriptase-polymerase chain reaction for BCR-ABL1 was performed 1.3 ± 0.7 times within the first 3 months (24 patients) and 2.7 ± 1.4 times in the following 12 months (18 patients). With a median follow-up of 36.5 months (range, 3.2-67.4 months), the probabilities of treatment-free remission at 1 year and 2 years were 65.7% (95% confidence interval, 55.8%-75.6%) and 59.7% (95% confidence interval, 49.1%-70.3%), respectively. Loss of MMR was observed in 9 patients at a median of 2.8 months (range, 1.8-14.2 months) after discontinuation of TKIs. CONCLUSIONS: With the limitations of a small sample size, the results of the current study demonstrate that less frequent monitoring of BCR-ABL1 does not appear to affect outcomes, and that discontinuation of TKIs used as first-line treatment or beyond after resistance or intolerance to first-line treatment appears feasible. Cancer 2017;123:2482-88. © 2017 American Cancer Society.

Momelotinib in myelofibrosis: JAK1/2 inhibitor with a role in treating and understanding the anemia.

Myelofibrosis (MF) is a chronic malignancy of the blood-forming system caused by hyperactivation of JAK2/STAT signaling pathway. Small-molecule inhibitors of JAK2 can variably ameliorate MF-related symptoms caused by chronic inflammation and hepatosplenomegaly. Anemia is a significant problem and adverse prognostic factor in over a third of MF patients and is often worsened by JAK2 inhibitors. The JAK1/2 inhibitor momelotinib unexpectedly resulted in reduction of anemia in MF patients during Phase I/II trials. Current Phase III trials will be the basis for seeking regulatory approval of momelotinib during 2017. Studies to determine how momelotinib improves anemia are underway, potentially leading to expanded momelotinib use and/or development of other targeted therapies for treating anemia in MF and related diseases.

Primary analysis of a phase II open-label trial of INCB039110, a selective JAK1 inhibitor, in patients with myelofibrosis.

Combined Janus kinase 1 (JAK1) and JAK2 inhibition therapy effectively reduces splenomegaly and symptom burden related to myelofibrosis but is associated with dose-dependent anemia and thrombocytopenia. In this open-label phase II study, we evaluated the efficacy and safety of three dose levels of INCB039110, a potent and selective oral JAK1 inhibitor, in patients with intermediate- or high-risk myelofibrosis and a platelet count ≥50×109/L. Of 10, 45, and 32 patients enrolled in the 100 mg twice-daily, 200 mg twice-daily, and 600 mg once-daily cohorts, respectively, 50.0%, 64.4%, and 68.8% completed week 24. A ≥50% reduction in total symptom score was achieved by 35.7% and 28.6% of patients in the 200 mg twice-daily cohort and 32.3% and 35.5% in the 600 mg once-daily cohort at week 12 (primary end point) and 24, respectively. By contrast, two patients (20%) in the 100 mg twice-daily cohort had ≥50% total symptom score reduction at weeks 12 and 24. For the 200 mg twice-daily and 600 mg once-daily cohorts, the median spleen volume reductions at week 12 were 14.2% and 17.4%, respectively. Furthermore, 21/39 (53.8%) patients who required red blood cell transfusions during the 12 weeks preceding treatment initiation achieved a ≥50% reduction in the number of red blood cell units transfused during study weeks 1-24. Only one patient discontinued for grade 3 thrombocytopenia. Non-hematologic adverse events were largely grade 1 or 2; the most common was fatigue. Treatment with INCB039110 resulted in clinically meaningful symptom relief, modest spleen volume reduction, and limited myelosuppression.

Combination of GM-CSF With Fludarabine-Containing Regimens in Chronic Lymphocytic Leukemia and Indolent Non-Hodgkin Lymphoma.

BACKGROUND: Granulocyte-monocyte colony stimulating factor (GM-CSF) is a hematopoietic cytokine with immunomodulatory activity that has preclinical evidence for enhancement of antitumor immunity when administered in combination with chemotherapy. We evaluated the utility of GM-CSF with chemoimmunotherapy in patients with indolent non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) in a pilot study. PATIENTS AND METHODS: Patients with previously untreated, relapsed, or refractory indolent NHL or CLL were treated with GM-CSF, rituximab, fludarabine, and cyclophosphamide or mitoxantrone for a maximum of 6 cycles. RESULTS: Sixteen patients were enrolled, including 1 patient who did not receive study therapy. Of the 15 remaining patients, 6 received cyclophosphamide and 9 received mitoxantrone in combination with fludarabine, rituximab, and GM-CSF. The overall response rate for all patients was 87%. Nine patients have subsequently had relapse of their disease, and 6 remained in remission at last study contact. There were no toxic deaths during the study. CONCLUSION: GM-CSF-based chemoimmunotherapy was well-tolerated and resulted in a high response rate and warrants evaluation in larger studies.

Ruxolitinib for the treatment of patients with polycythemia vera.

Polycythemia vera (PV) is a hematopoietic proliferative disorder associated with Janus-associated kinase/signal transducer and activator of transcription pathway dysregulation resulting in erythrocytosis and, possibly, leukocytosis and thrombocytosis. Patients diagnosed with PV experience a broad range of symptoms associated with a reduced quality of life, often develop splenomegaly, and have an increased risk of death compared with age-matched subjects without PV. Current treatment options, notably hydroxyurea, help with disease management; however, insufficient efficacy or progressive resistance occurs in some patients, highlighting the need for new treatment options. Ruxolitinib is an oral JAK1/JAK2 inhibitor that has been evaluated in Phase II and III clinical trials in patients with PV, who are intolerant of or resistant to hydroxyurea. In this setting, ruxolitinib treatment has demonstrated normalization of blood cell counts, reduction in splenomegaly and improvements in PV-related symptom burden.

Efficacy, safety, and survival with ruxolitinib in patients with myelofibrosis: results of a median 3-year follow-up of COMFORT-I.

In the phase III COMFORT-I study, the Janus kinase 1 (JAK1)/JAK2 inhibitor ruxolitinib provided significant improvements in splenomegaly, key symptoms, and quality-of-life measures and was associated with an overall survival benefit relative to placebo in patients with intermediate-2 or high-risk myelofibrosis. This planned analysis assessed the long-term efficacy and safety of ruxolitinib at a median follow-up of 149 weeks. At data cutoff, approximately 50% of patients originally randomized to ruxolitinib remained on treatment whereas all patients originally assigned to placebo had discontinued or crossed over to ruxolitinib. At week 144, mean spleen volume reduction was 34% with ruxolitinib. Previously observed improvements in quality-of-life measures were sustained with longer-term ruxolitinib therapy. Overall survival continued to favor ruxolitinib despite the majority of placebo patients crossing over to ruxolitinib [hazard ratio 0.69 (95% confidence interval: 0.46-1.03); P = 0.067]. Exploratory analyses suggest that crossover may have contributed to an underestimation of the true survival difference between the treatment groups. Ruxolitinib continued to be generally well tolerated; there was no pattern of worsening grade ≥ 3 anemia or thrombocytopenia with longer-term ruxolitinib exposure. These longer-term data continue to support the efficacy and safety of ruxolitinib in patients with myelofibrosis. The study is registered at clinicaltrials.gov: NCT00952289.

Predicting early blast transformation in chronic-phase chronic myeloid leukemia: is immunophenotyping the missing link?

BACKGROUND: Flow cytometry (FC) is a commonly requested test in the workup of leukocytosis in community practices. The role of FC in chronic-phase chronic myeloid leukemia (CP-CML) is unknown. We hypothesized that finding aberrant cells with FC in CP-CML may predict early blast-phase (BP) transformation. METHODS: Results for FC performed at the time of diagnosis for adult and pediatric patients with CP-CML who were referred to our institution were reviewed, and they were correlated with outcomes. RESULTS: FC was performed at the time of diagnosis for 110 of 233 patients (47%) with CP-CML. Aberrant populations, representing a median of 2% (range, 0.3%-15%), were detected with FC in 30% of patients (33 of 110): 2 of these 33 patients expressed lymphoid markers, and 31 expressed aberrant myeloid markers. Patients received imatinib (85%), dasatinib (12%), or nilotinib (3%) as their first-line treatment. With a median follow-up of 43 months (range, 2-113 months), chronic myeloid leukemia transformed to BP in 5 of the 33 patients. The 2 patients with lymphoid markers and the 3 of 31 patients with aberrant myeloid markers experienced a transformation to lymphoid BP at a median of 11 months (range, 4-72 months) after the initiation of tyrosine kinase inhibitor therapy. Although both cases with detectable lymphoid markers rapidly progressed to lymphoid BP, the positive predictive value of BP transformation by the detection of myeloid aberrant cells with FC was only 10% (3 of 31). CONCLUSIONS: In contrast to aberrant myeloid markers, the detection of lymphoid markers by FC at the time of the diagnosis of CP-CML appears to be associated with early progression to lymphoid BP.