Efficacy and safety of avatrombopag in combination with immunosuppressive therapy in treatment-naïve and relapsed/refractory severe aplastic anaemia: protocol for the DIAAMOND-Ava-FIRST and DIAAMOND-Ava-NEXT Bayesian Optimal Phase II trials.

INTRODUCTION: Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and ciclosporin is standard of care for patients with severe aplastic anaemia (sAA) not eligible or suitable for allogeneic stem cell transplant. While patients respond to IST, few achieve complete responses and a significant proportion are refractory or relapse. The addition of eltrombopag, a thrombopoietin-receptor agonist (TPO-A), to IST has been shown to improve haematological responses in sAA. Avatrombopag is a second-generation TPO-A with potential advantages over eltrombopag. However, to date avatrombopag has not been studied in sAA. METHODS AND ANALYSIS: Investigator-initiated, single-arm registry-based Bayesian Optimal Phase II trial of avatrombopag conducted in two cohorts, patients with untreated sAA (FIRST cohort) and in patients with sAA that has relapsed or is refractory to IST (NEXT cohort). In the FIRST cohort, participants receive IST (equine ATG and ciclosporin) plus avatrombopag from day 1 until day 180 at 60 mg oral daily, with dose adjusted according to platelet count. Participants in the NEXT cohort receive avatrombopag at 60 mg oral daily from day 1 until day 180, with or without additional IST at the discretion of the treating clinician.For each cohort, two primary endpoints (haematological response and acquired clonal evolution) are jointly monitored and the trial reviewed at each interim analysis where a 'go/no-go' decision is made by evaluating the posterior probability of the events of interests. ETHICS AND DISSEMINATION: The trial has received ethics approval (Monash Health RES-18-0000707A). The trial conduct will comply with ICH-GCP and all applicable regulatory requirements. The results of the trial will be submitted to a peer-review journal for publication. TRIAL REGISTRATION NUMBER: ACTRN12619001042134, ACTRN12619001043123.

Rilzabrutinib, an Oral BTK Inhibitor, in Immune Thrombocytopenia.

BACKGROUND: Rilzabrutinib, an oral, reversible covalent inhibitor of Bruton's tyrosine kinase, may increase platelet counts in patients with immune thrombocytopenia by means of dual mechanisms of action: decreased macrophage (Fcγ receptor)-mediated platelet destruction and reduced production of pathogenic autoantibodies. METHODS: In an international, adaptive, open-label, dose-finding, phase 1-2 clinical trial, we evaluated rilzabrutinib therapy in previously treated patients with immune thrombocytopenia. We used intrapatient dose escalation of oral rilzabrutinib over a period of 24 weeks; the lowest starting dose was 200 mg once daily, with higher starting doses of 400 mg once daily, 300 mg twice daily, and 400 mg twice daily. The primary end points were safety and platelet response (defined as at least two consecutive platelet counts of ≥50×103 per cubic millimeter and an increase from baseline of ≥20×103 per cubic millimeter without the use of rescue medication). RESULTS: Sixty patients were enrolled. At baseline, the median platelet count was 15×103 per cubic millimeter, the median duration of disease was 6.3 years, and patients had received a median of four different immune thrombocytopenia therapies previously. All the treatment-related adverse events were of grade 1 or 2 and transient. There were no treatment-related bleeding or thrombotic events of grade 2 or higher. At a median of 167.5 days (range, 4 to 293) of treatment, 24 of 60 patients (40%) overall and 18 of the 45 patients (40%) who had started rilzabrutinib treatment at the highest dose met the primary end point of platelet response. The median time to the first platelet count of at least 50×103 per cubic millimeter was 11.5 days. Among patients with a primary platelet response, the mean percentage of weeks with a platelet count of at least 50×103 per cubic millimeter was 65%. CONCLUSIONS: Rilzabrutinib was active and associated with only low-level toxic effects at all dose levels. The dose of 400 mg twice daily was identified as the dose for further testing. Overall, rilzabrutinib showed a rapid and durable clinical activity that improved with length of treatment. (Funded by Sanofi; ClinicalTrials.gov number, NCT03395210; EudraCT number, 2017-004012-19.).

Distinguishing human peripheral blood CD16+ myeloid cells based on phenotypic characteristics.

Myeloid lineage cells present in human peripheral blood include dendritic cells (DC) and monocytes. The DC are identified phenotypically as HLA-DR+ cells that lack major cell surface lineage markers for T cells (CD3), B cells (CD19, CD20), NK cells (CD56), red blood cells (CD235a), hematopoietic stem cells (CD34), and Mo that express CD14. Both DC and Mo can be phenotypically divided into subsets. DC are divided into plasmacytoid DC, which are CD11c- , CD304+ , CD85g+ , and myeloid DC that are CD11c+ . The CD11c+ DC are readily classified as CD1c+ DC and CD141+ DC. Monocytes are broadly divided into the CD14+ CD16- (classical) and CD14dim CD16+ subsets (nonclassical). A population of myeloid-derived cells that have DC characteristics, that is, HLA-DR+ and lacking lineage markers including CD14, but express CD16 are generally clustered with CD14dim CD16+ monocytes. We used high-dimensional clustering analyses of fluorescence and mass cytometry data, to delineate CD14+ monocytes, CD14dim CD16+ monocytes (CD16+ Mo), and CD14- CD16+ DC (CD16+ DC). We sought to identify the functional and kinetic relationship of CD16+ DC to CD16+ Mo. We demonstrate that differentiation of CD16+ DC and CD16+ Mo during activation with IFNγ in vitro and as a result of an allo-hematopoietic cell transplant (HCT) in vivo resulted in distinct populations. Recovery of blood CD16+ DC in both auto- and allo-(HCT) patients after myeloablative conditioning showed similar reconstitution and activation kinetics to CD16+ Mo. Finally, we show that expression of the cell surface markers CD300c, CCR5, and CLEC5a can distinguish the cell populations phenotypically paving the way for functional differentiation as new reagents become available.

Examination of CD302 as a potential therapeutic target for acute myeloid leukemia.

Acute myeloid leukemia (AML) is the most common form of adult acute leukemia with ~20,000 new cases yearly. The disease develops in people of all ages, but is more prominent in the elderly, who due to limited treatment options, have poor overall survival rates. Monoclonal antibodies (mAb) targeting specific cell surface molecules have proven to be safe and effective in different haematological malignancies. However, AML target molecules are currently limited so discovery of new targets would be highly beneficial to patients. We examined the C-type lectin receptor CD302 as a potential therapeutic target for AML due to its selective expression in myeloid immune populations. In a cohort of 33 AML patients with varied morphological and karyotypic classifications, 88% were found to express CD302 on the surface of blasts and 80% on the surface of CD34+ CD38- population enriched with leukemic stem cells. A mAb targeting human CD302 was effective in mediating antibody dependent cell cytotoxicity and was internalised, making it amenable to toxin conjugation. Targeting CD302 with antibody limited in vivo engraftment of the leukemic cell line HL-60 in NOD/SCID mice. While CD302 was expressed in a hepatic cell line, HepG2, this molecule was not detected on the surface of HepG2, nor could HepG2 be killed using a CD302 antibody-drug conjugate. Expression was however found on the surface of haematopoietic stem cells suggesting that targeting CD302 would be most effective prior to haematopoietic transplantation. These studies provide the foundation for examining CD302 as a potential therapeutic target for AML.

Azacitidine with or without lenalidomide in higher risk myelodysplastic syndrome & low blast acute myeloid leukemia.

Standard treatment for higher risk myelodysplastic syndromes, chronic myelomonocytic leukemia and low blast acute myeloid leukemia is azacitidine. In single arm studies, adding lenalidomide had been suggested to improve outcomes. The ALLG MDS4 phase II trial randomized such patients to standard azacitidine or combination azacitidine (75mg/m2/d days 1 to 5) with lenalidomide (10mg days 1-21 of 28-day cycle from cycle 3) to assess clinical benefit (alive without progressive disease) at 12 months. A total of 160 patients were enrolled; median age 70.7 years (range 42.5-87.2), 31.3% female with 14% chronic myelomonocytic leukemia, 12% acute myeloid leukemia and 74% myelodysplastic syndromes. Adverse events were similar in both arms. There was excellent delivery of protocol therapy (median azacitidine cycles 11 both arms) with few dose reductions, delays or early cessations. At median follow up 33.1 months (range 0.7-59.5), the rate of clinical benefit at 12 months was 65% azacitidine arm and 54% lenalidomide+azacitidine arm (P=0.2). There was no difference in clinical benefit between each arm according to WHO diagnostic subgroup or IPSS-R. Overall response rate was 57% in azacitidine arm and 69% in lenalidomide+azacitidine (P=0.14). There was no difference in progression- free or overall survival between the arms (each P>0.12). Although the combination of lenalidomide and azacitidine was tolerable, there was no improvement in clinical benefit, response rates or overall survival in higher risk myelodysplastic syndrome, chronic myelomonocytic leukemia or low blast acute myeloid leukemia patients compared to treatment with azacitidine alone. This trial was registered at www.anzc-tr.org.au as ACTRN12610000271000.

Characteristics of older people in an inpatient haematology unit: A descriptive study.

OBJECTIVE: To characterise older inpatients in a haematology unit. METHODS: Hospital case-mix data of haematology separations of all ages (n = 7419) and more extensive data restricted to older patients (age ≥75 years, n = 1025) were evaluated. RESULTS: From 2000 to 2014, there was a 200% increase in those aged ≥85 years who were more likely to have a geriatric syndrome as the principal diagnosis (P < 0.05), have delirium (P < 0.05), receive less intensive treatment (P < 0.001) and be discharged to a nursing home (P < 0.001). Compared to younger inpatients, those aged ≥75 years were more likely to be emergency admissions (48% vs 37%, P < 0.001) and die during the admission (8% vs 4%, P < 0.001). CONCLUSION: Haematologists care for older inpatients who are complex with multidisciplinary health service needs. There may be value in conducting comprehensive geriatric assessments in this setting.

CD83 is a new potential biomarker and therapeutic target for Hodgkin lymphoma.

Chemotherapy and hematopoietic stem cell transplantation are effective treatments for most Hodgkin lymphoma patients, however there remains a need for better tumor-specific target therapy in Hodgkin lymphoma patients with refractory or relapsed disease. Herein, we demonstrate that membrane CD83 is a diagnostic and therapeutic target, highly expressed in Hodgkin lymphoma cell lines and Hodgkin and Reed-Sternberg cells in 29/35 (82.9%) Hodgkin lymphoma patient lymph node biopsies. CD83 from Hodgkin lymphoma tumor cells was able to trogocytose to surrounding T cells and, interestingly, the trogocytosing CD83+T cells expressed significantly more programmed death-1 compared to CD83-T cells. Hodgkin lymphoma tumor cells secreted soluble CD83 that inhibited T-cell proliferation, and anti-CD83 antibody partially reversed the inhibitory effect. High levels of soluble CD83 were detected in Hodgkin lymphoma patient sera, which returned to normal in patients who had good clinical responses to chemotherapy confirmed by positron emission tomography scans. We generated a human anti-human CD83 antibody, 3C12C, and its toxin monomethyl auristatin E conjugate, that killed CD83 positive Hodgkin lymphoma cells but not CD83 negative cells. The 3C12C antibody was tested in dose escalation studies in non-human primates. No toxicity was observed, but there was evidence of CD83 positive target cell depletion. These data establish CD83 as a potential biomarker and therapeutic target in Hodgkin lymphoma.

Idarubicin Dose Escalation During Consolidation Therapy for Adult Acute Myeloid Leukemia.

Purpose Higher doses of the anthracycline daunorubicin during induction therapy for acute myeloid leukemia (AML) have been shown to improve remission rates and survival. We hypothesized that improvements in outcomes in adult AML may be further achieved by increased anthracycline dose during consolidation therapy. Patients and Methods Patients with AML in complete remission after induction therapy were randomly assigned to receive two cycles of consolidation therapy with cytarabine 100 mg/m2 daily for 5 days, etoposide 75 mg/m2 daily for 5 days, and idarubicin 9 mg/m2 daily for either 2 or 3 days (standard and intensive arms, respectively). The primary end point was leukemia-free survival (LFS). Results Two hundred ninety-three patients 16 to 60 years of age, excluding those with core binding factor AML and acute promyelocytic leukemia, were randomly assigned to treatment groups (146 to the standard arm and 147 to the intensive arm). Both groups were balanced for age, karyotypic risk, and FLT3-internal tandem duplication and NPM1 gene mutations. One hundred twenty patients in the standard arm (82%) and 95 patients in the intensive arm (65%) completed planned consolidation ( P < .001). Durations of severe neutropenia and thrombocytopenia were prolonged in the intensive arm, but there were no differences in serious nonhematological toxicities. With a median follow-up of 5.3 years (range, 0.6 to 9.9 years), there was a statistically significant improvement in LFS in the intensive arm compared with the standard arm (3-year LFS, 47% [95% CI, 40% to 56%] v 35% [95% CI, 28% to 44%]; P = .045). At 5 years, the overall survival rate was 57% in the intensive arm and 47% in the standard arm ( P = .092). There was no evidence of selective benefit of intensive consolidation within the cytogenetic or FLT3-internal tandem duplication and NPM1 gene mutation subgroups. Conclusion An increased cumulative dose of idarubicin during consolidation therapy for adult AML resulted in improved LFS, without increased nonhematologic toxicity.

Formalising multidisciplinary peer review: developing a haematological malignancy-specific electronic proforma and standard operating procedure to facilitate procedural efficiency and evidence-based clinical practice.

BACKGROUND: Multidisciplinary team (MDT) meetings aimed at facilitating peer review have become standard practice in oncology. However, there is scant literature on the optimal structure and conduct of such meetings. AIMS: To develop a process for formal peer review of patients with haematological malignancies and to audit any resulting changes made to the management recommendations of the treating physician. METHODS: A standard operating procedure (SOP) for MDT meetings was developed essentially to integrate clinical peer review with weekly pathology and radiology meetings. The centrepiece is the electronic submission of a patient-specific proforma (Microsoft InfoPath) prior to the meeting. It serves as the template for presentation, discussion and recording of recommendations and conclusions. The final verified document is stored in the electronic patient record, and a copy is sent to the general practitioner. The proposed management plans were compared to the consensus recommendations of the meeting for the first 4 years since inception. RESULTS: Both SOP and proforma underwent continual improvements. These provided the framework for the conduct of a robust weekly MDT meeting for peer review of the management of patients with haematological malignancies. On 20% of occasions, patient management plans were altered to optimise patient care as a direct consequence on peer review at the MDT. CONCLUSION: Our streamlined process, in its ultimate format, has provided a mature and efficient forum for formal peer review in a genuine multidisciplinary environment. Both initial data and informal feedback support its ongoing activity as an integral component of delivering quality patient care.

A CD2 high-expressing stress-resistant human plasmacytoid dendritic-cell subset.

Human plasmacytoid dendritic cells (pDCs) were considered to be a phenotypically and functionally homogeneous cell population; however, recent analyses indicate potential heterogeneity. This is of major interest, given their importance in the induction of anti-viral responses and their role in creating immunologically permissive environments for human malignancies. For this reason, we investigated the possible presence of human pDC subsets in blood and bone marrow, using unbiased cell phenotype clustering and functional studies. This defined two major functionally distinct human pDC subsets, distinguished by differential expression of CD2. The CD2(hi) and CD2(lo) pDCs represent discontinuous subsets, each with hallmark pDC functionality, including interferon-alpha production. The rarer CD2(hi) pDC subset demonstrated a significant survival advantage over CD2(lo) pDC during stress and upon exposure to glucocorticoids (GCs), which was associated with higher expression of the anti-apoptotic molecule BCL2. The differential sensitivity of these two human pDC subsets to GCs is demonstrated in vivo by a relative increase in CD2(hi) pDC in multiple myeloma patients treated with GCs. Hence, the selective apoptosis of CD2(lo) pDC during stress represents a novel mechanism for the control of innate responses.

Trough serum testosterone predicts the development of polycythemia in hypogonadal men treated for up to 21 years with subcutaneous testosterone pellets.

OBJECTIVES: Testosterone formulations that have more steady-state pharmacokinetics, such as subcutaneously implanted testosterone pellets, may cause less erythrocytosis than i.m. injections of shorter acting androgen esters. We, therefore, sought to define the prevalence, predictors, and proximate basis (role of erythropoietin) for polycythemia (hematocrit >0.50) in hypogonadal men receiving testosterone implants long term. DESIGN: A cross-sectional study was conducted in an academic andrology center with a longitudinal subgroup analysis. PATIENTS: A total of 158 hypogonadal men aged 14-84 years (mean age 46.7 years) treated on average for 8 years (range 0-21 years). MEASUREMENTS: Trough blood testosterone and hematocrit. Serial serum erythropoietin concentrations were measured in 16 volunteers. RESULTS: Positive univariate associations between polycythemia (hematocrit >0.50) and log(testosterone) (odds ratio (OR) 24.7, 95% confidence interval (CI): 4.3, 141.2, P<0.01) and age (OR 1.1, 95% CI: 1.0, 1.1, P=0.03) and a borderline relationship with current smoking (OR 4.2, 95% CI: 0.9, 20.0, P=0.08) were unveiled. A sensitivity analysis using alternate definitions of polycythemia was performed to capture all potential covariants. Multivariate regression analysis incorporating all potential covariants disclosed the independent OR of developing polycythemia (after adjusting for smoking and age) for log(testosterone) to be 15.0 (95% CI: 2.5, 90.8). Duration of testosterone therapy did not alter the risk of polycythemia. A direct relationship between testosterone and erythropoietin was observed (P=0.05). CONCLUSIONS: Higher trough serum testosterone concentrations but not duration of treatment predict the development of polycythemia in men receiving long-acting depot testosterone treatment.

Clinical skills in junior medical officers: a comparison of self-reported confidence and observed competence.

BACKGROUND: The intern year is a key time for the acquisition of clinical skills, both procedural and cognitive. We have previously described self-reported confidence and experience for a number of clinical skills, finding high levels of confidence among Australian junior doctors. This has never been correlated with an objective measure of competence. AIMS AND HYPOTHESIS: We aimed to determine the relationship between self-reported confidence and observed competence for a number of routine, procedural clinical skills. METHODS: A group of 30 junior medical officers in their first postgraduate year (PGY1) was studied. All subjects completed a questionnaire concerning their confidence and experience in the performance of clinical skills. A competency-based assessment instrument concerning 7 common, practical, clinical skills was developed, piloted and refined. All 30 PGY1s then completed an assessment using this instrument. Comparisons were then made between the PGY1s' self-reported levels of confidence and tutors' assessments of their competence. RESULTS: A broad range of competence levels was revealed by the clinical skills assessments. There was no correlation between the PGY1s' self-ratings of confidence and their measured competencies. CONCLUSIONS: Junior medical officers in PGY1 demonstrate a broad range of competence levels for several common, practical, clinical skills, with some performing at an inadequate level. There is no relationship between their self-reported level of confidence and their formally assessed performance. This observation raises important caveats about the use of self-assessment in this group.