Pacritinib is a potent ACVR1 inhibitor with significant anemia benefit in patients with myelofibrosis.

In patients with cytopenic myelofibrosis, treatment with the JAK2/IRAK1 inhibitor pacritinib was associated with anemia benefit in the phase 3 PERSIST-2 study. The impact of pacritinib on transfusion independence (TI) has not been previously described, nor has the mechanism by which pacritinib improves anemia been elucidated. Because it has been previously postulated that inhibition of activin A receptor, type 1 (ACVR1)/activin receptor-like kinase-2 improves anemia in patients with myelofibrosis via suppression of hepcidin production, we assessed the relative inhibitory potency of pacritinib compared with other JAK2 inhibitors against ACVR1. Pacritinib inhibited ACVR1 with greater potency (half-maximal inhibitory concentration [IC50] = 16.7 nM; Cmax:IC50 = 12.7) than momelotinib (IC50 = 52.5 nM; Cmax:IC50 = 3.2), fedratinib (IC50 = 273 nM; Cmax:IC50 = 1.0), or ruxolitinib (IC50 > 1000; Cmax:IC50 < 0.01). Pacritinib's inhibitory activity against ACVR1 was corroborated via inhibition of downstream SMAD signaling in conjunction with marked suppression of hepcidin production. Among patients on PERSIST-2 who were not transfusion independent at baseline based on Gale criteria, a significantly greater proportion achieved TI on pacritinib compared with those treated on best available therapy (37% vs 7%, P = .001), and significantly more had a ≥50% reduction in transfusion burden (49% vs 9%, P < .0001). These data indicate that the anemia benefit of the JAK2/IRAK1 inhibitor pacritinib may be a function of potent ACVR1 inhibition.

Retrospective analysis of pacritinib in patients with myelofibrosis and severe thrombocytopenia.

Thrombocytopenia is common in patients with myelofibrosis (MF) and is a well-established adverse prognostic factor. Both of the approved Janus kinase (JAK) inhibitors, ruxolitinib and fedratinib, can worsen thrombocytopenia and have not been evaluated in patients with severe thrombocytopenia (platelet counts <50×109/L). Pacritinib, a novel JAK2/interleukin-1 receptor-associated kinase 1 inhibitor, has been studied in two phase III trials (PERSIST-1 and PERSIST- 2), both of which enrolled patients with MF and severe thrombocytopenia. In order to better characterize treatment outcomes for this population with advanced disease, we present a retrospective analysis of efficacy and safety data in the 189 patients with severe thrombocytopenia treated in the PERSIST studies. The proportion of patients in the pacritinib group meeting efficacy endpoints was greater than in the BAT group for ≥35% spleen volume reduction (23% vs. 2%, P=0.0007), ≥50% modified Total Symptom Score reduction (25% vs. 8%, P=0.044), and self-reported symptom benefit ("much" or "very much" improved; 25% vs. 8%, P=0.016) at the primary analysis time point (week 24). The adverse event profile of pacritinib was manageable, and dose modification was rarely required. There was no excess in bleeding or death in pacritinib-treated patients. These results indicate that pacritinib is a promising treatment for patients with MF who lack safe and effective therapeutic options due to severe thrombocytopenia.

Determining the recommended dose of pacritinib: results from the PAC203 dose-finding trial in advanced myelofibrosis.

PAC203 is a randomized dose-finding study of pacritinib, an oral JAK2/IRAK1 inhibitor, in patients with advanced myelofibrosis who are intolerant of or resistant to ruxolitinib. Patients were randomized 1:1:1 to pacritinib 100 mg once per day, 100 mg twice per day, or 200 mg twice per day. Enhanced eligibility criteria, monitoring, and dose modifications were implemented to mitigate risk of cardiac and hemorrhagic events. Efficacy was based on ≥35% spleen volume response (SVR) and ≥50% reduction in the 7-component total symptom score (TSS) through week 24. Of 161 patients, 73% were intolerant of and 76% had become resistant to ruxolitinib; 50% met criteria for both. Severe thrombocytopenia (platelet count <50 × 103/µL) was present in 44%. SVR rates were highest with 200 mg twice per day (100 mg once per day, 0%; 100 mg twice per day, 1.8%; 200 mg twice per day, 9.3%), particularly among patients with baseline platelet counts <50 × 103/µL (17%; 4 of 24). Although TSS response rate was similar across doses (100 mg once per day, 7.7%; 100 mg twice per day, 7.3%; 200 mg twice per day, 7.4%), median percent reduction in TSS suggested a dose-response relationship (-3%, -16%, and -27%, respectively). Pharmacokinetic and pharmacodynamic modeling based on all available data showed greatest SVR and TSS reduction at 200 mg twice per day compared with lower doses. Common adverse events were gastrointestinal events, thrombocytopenia, and anemia. There was no excess of grade ≥3 hemorrhagic or cardiac events at 200 mg twice per day. Pacritinib 200 mg twice per day demonstrated clinical activity and an acceptable safety profile and was selected as the recommended dose for a pivotal phase 3 study in patients with myelofibrosis and severe thrombocytopenia. This trial was registered at www.clinicaltrials.gov as #NCT03165734.

Development and validation of the AML-QOL: a quality of life instrument for patients with acute myeloid leukemia.

There is currently no validated quality of life (QOL) instrument specific to patients with acute myeloid leukemia (AML). A previous cross-sectional interview-based study elicited concepts for inclusion in a novel QOL instrument. Here, we further develop and validate this new instrument, the AML-QOL. Iterative revisions of the draft AML-QOL were refined based on feedback from 16 patients, 8 medical providers, and 3 psychometricians. The instrument underwent factor analysis based on responses from 202 patients with AML and analogous aggressive myeloid neoplasms receiving AML-like therapy. A prospective validation study was then undertaken in 50 patients who completed the AML-QOL at multiple time points while undergoing a cycle of intensive chemotherapy to establish test-retest reliability and sensitivity to change. The final AML-QOL contains 27 items and is categorized into 5 domains (Physical, Social, Cognitive, Anxiety, Depression), one Symptom Index, a single item assessing overall quality of life, and a Summary Score. The AML-QOL domains show high internal consistency (median alpha: 0.85), good test-retest reliability (median interclass correlation: 0.82), and had convergent and divergent validity when compared to a non-disease-specific instrument (the EORTC QLQ-C30). The Summary Score demonstrated good sensitivity to change when anchored to patient perception of QOL change. The AML-QOL is a reliable and valid measure of QOL in patients with AML and analogous aggressive myeloid neoplasms. A clinically meaningful difference is 8-10 points out of 100 on the Summary Score.

A comparison of patients with acute myeloid leukemia and high-risk myelodysplastic syndrome treated on versus off study.

Patients with newly diagnosed (ND) and relapsed/refractory (RR) acute myeloid leukemia (AML) and high-risk myelodysplastic syndrome (MDS, ≥10% blasts) often receive intensive chemotherapy at diagnosis and relapse. We retrospectively identified 365 patients and categorized the reasons for receiving treatment off study (medical, logistical, or unclear). The pretreatment characteristics of the on and off study groups were similar. Rates of the complete remission (CR) without measurable residual disease were significantly higher for ND patients treated on versus off study (61% versus 35%), but CR rates and survival were low for all RR patients regardless of study assignment. The subset of ND patients treated off study for medical reasons had significantly decreased overall survival and relapse-free survival. Standard, stringent study eligibility criteria may delineate a population of ND, but not RR, patients with improved outcomes with intensive induction chemotherapy.

Phase 1/2 trial of GCLAM with dose-escalated mitoxantrone for newly diagnosed AML or other high-grade myeloid neoplasms.

Outcomes with "7 + 3" are often unsatisfactory in acute myeloid leukemia (AML). Trials demonstrating improved outcomes with high-dose cytarabine, addition of cladribine, or escalated anthracycline doses prompted a phase 1/2 study (NCT02044796) of G-CSF, cladribine, high-dose cytarabine, and dose-escalated mitoxantrone (GCLAM) in adults with newly-diagnosed AML or other high-grade myeloid neoplasms. One hundred and twenty-one patients, median age 60 (range 21-81) years, were enrolled. In phase 1, cohorts of 6-12 patients were assigned to 12-18 mg/m2/day of mitoxantrone as part of GCLAM. Because all dose levels were well-tolerated, mitoxantrone at 18 mg/m2 was declared the recommended phase 2 dose (RP2D). 74/94 (79%) patients treated at the RP2D achieved a complete remission (CR; 67/74 without measureable residual disease [MRD]) for an overall MRDneg CR rate of 71% (primary phase 2 endpoint). Seven patients achieved a CR with incomplete blood count recovery (CRi; 7%, 5 MRDneg) for a CR/CRi rate of 81/94 (86%). Four-week mortality was 2%. After adjustment, the MRDneg CR and CR/CRi rates compared favorably to 100 matched controls treated with 7 + 3 at our center and 245 matched patients treated with 7 + 3 on a cooperative group trial. Our data indicate GCLAM with mitoxantrone at 18 mg/m2/day is safe and induces high-quality remissions in adults with newly-diagnosed AML.

Successful Treatment of Cannabinoid Hyperemesis Syndrome with Topical Capsaicin.

Cannabinoid hyperemesis syndrome (CHS) is a clinical entity in which marijuana users develop nausea, vomiting, and abdominal pain that improves with hot water bathing or cannabis cessation. Previous models suggest that CHS arises solely from the derangement of cannabinoid receptor type 1 signaling. However, involvement of transient receptor potential vanilloid subtype 1 (TRPV1) receptor, which is activated by marijuana, capsaicin, and heat, could fill gaps in existing models, including the enigmatic role of hot water bathing. We propose that chronic cannabis use decreases TRPV1 signaling and alters gastric motility, and we report the case of a CHS patient whose symptoms improved after topical capsaicin.

Quality of life from the perspective of the patient with acute myeloid leukemia.

BACKGROUND: Although outcomes for acute myeloid leukemia (AML) have improved over time, they remain poor overall, and toxicity from both the disease and its treatment can affect quality of life (QOL). One barrier to including QOL endpoints in clinical trials is the lack of a disease-specific QOL instrument that can efficiently capture the major QOL deficits in this population. METHODS: A cross-sectional study was performed to elicit concepts for inclusion in a new AML-specific QOL instrument called the AML-QOL. Eighty-two patients at various stages of disease were interviewed about sources of support (positive concepts) and problems and symptoms (negative concepts) experienced over the past week, and they were asked to grade how much each affected their QOL. In addition, patients were asked to complete 2 validated instruments: the Functional Assessment of Cancer Therapy with the leukemia and transplant modules and the 29-item Patient-Reported Outcomes Measurement Information System questionnaire. RESULTS: With data from the open-ended and questionnaire-based portions of the interview, 7 positive concepts and 64 negative concepts were elicited. From these, 5 positive concepts and 21 negative concepts were selected for inclusion in the preliminary AML-QOL on the basis of concept prevalence and the impact on QOL. CONCLUSIONS: These concepts will form the basis of a new QOL instrument specific to AML. Cancer 2018;124:145-52. © 2017 American Cancer Society.

Patient-reported outcomes in acute myeloid leukemia: Where are we now?

Outcomes for acute myeloid leukemia remain poor, and treatment decisions must consider not just quantity, but also quality of life (QOL). We conducted a systematic review of studies in patients with acute myeloid leukemia or high-risk myelodysplastic syndrome that incorporated patient-reported outcome (PRO) measures. PubMed and PsycINFO were searched for articles published from January 2000 through June 2016. Forty-one were relevant for our review with more published in recent years. There was considerable inter-study heterogeneity in which instruments were used, and many studies employed multiple (often overlapping) instruments. Longitudinal studies in particular suffered from both high attrition rates due to disease-related mortality as well as waning compliance with questionnaire completion. There remain significant challenges to incorporation of PROs into leukemia trials. Despite these limitations, however, well-implemented PROs can provide important information beyond objective response outcomes and highlight areas of focus for clinicians caring for patients and for future research endeavors.

Minimal residual disease prior to allogeneic hematopoietic cell transplantation in acute myeloid leukemia: a meta-analysis.

Minimal residual disease prior to allogeneic hematopoietic cell transplantation has been associated with increased risk of relapse and death in patients with acute myeloid leukemia, but detection methodologies and results vary widely. We performed a systematic review and meta-analysis evaluating the prognostic role of minimal residual disease detected by polymerase chain reaction or multiparametric flow cytometry before transplant. We identified 19 articles published between January 2005 and June 2016 and extracted hazard ratios for leukemia-free survival, overall survival, and cumulative incidences of relapse and non-relapse mortality. Pre-transplant minimal residual disease was associated with worse leukemia-free survival (hazard ratio=2.76 [1.90-4.00]), overall survival (hazard ratio=2.36 [1.73-3.22]), and cumulative incidence of relapse (hazard ratio=3.65 [2.53-5.27]), but not non-relapse mortality (hazard ratio=1.12 [0.81-1.55]). These associations held regardless of detection method, conditioning intensity, and patient age. Adverse cytogenetics was not an independent risk factor for death or relapse. There was more heterogeneity among studies using flow cytometry-based than WT1 polymerase chain reaction-based detection (I2=75.1% vs. <0.1% for leukemia-free survival, 67.8% vs. <0.1% for overall survival, and 22.1% vs. <0.1% for cumulative incidence of relapse). These results demonstrate a strong relationship between pre-transplant minimal residual disease and post-transplant relapse and survival. Outcome heterogeneity among studies using flow-based methods may underscore site-specific methodological differences or differences in test performance and interpretation.

Lymphomatoid granulomatosis associated with azathioprine use for immune-mediated neuropathy.

Lymphomatoid granulomatosis (LG) is a rare Epstein-Barr virus-driven lymphoproliferative disorder that generally arises in immunosuppressed patients and which can be life-threatening. Here we describe the development of pulmonary LG in a patient on long-term azathioprine for immune-mediated neuropathy. Although azathioprine carries a boxed warning for malignancy, its association specifically with LG, an otherwise rare entity, is poorly recognised. Early recognition of drug-induced LG is critical, since discontinuation of the offending agent, and implementation of effective therapy can provide rapid clinical benefit in some patients. In this case, rituximab was used as an effective treatment for LG, which also provided an additional benefit of controlling the patient's underlying neuropathy. Further research is needed to identify vulnerable patients who are at high risk of developing drug-induced LG.

Outpatient care of patients with acute myeloid leukemia: Benefits, barriers, and future considerations.

Patients with acute myeloid leukemia (AML) who receive intensive induction or re-induction chemotherapy with curative intent typically experience prolonged cytopenias upon completion of treatment. Due to concerns regarding infection and bleeding risk as well as significant transfusion and supportive care requirements, patients have historically remained in the hospital until blood count recovery-a period of approximately 30 days. The rising cost of AML care has prompted physicians to reconsider this practice, and a number of small studies have suggested the safety and feasibility of providing outpatient supportive care to patients following intensive AML (re-) induction therapy. Potential benefits include a significant reduction of healthcare costs, improvement in quality of life, and decreased risk of hospital-acquired infections. In this article, we will review the currently available literature regarding this practice and discuss questions to be addressed in future studies. In addition, we will consider some of the barriers that must be overcome by institutions interested in implementing an "early discharge" policy. While outpatient management of selected AML patients appears safe, careful planning is required in order to provide the necessary support, education and rapid management of serious complications that occur among this very vulnerable patient population.