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Background:Thrombopoietin‐receptor‐agonists (TPO‐RA) are effective treatments of immune thrombocytopenia (ITP). Previous long‐term TPO‐RA clinical trials have shown that thrombotic events occurred in 6% of TPO‐RA‐treated ITP patients, with thrombotic events appearing to be more frequent in patients of older age and having at least 1 general risk factor for thrombosis.Aims:To evaluate the prevalence of venous and arterial thrombosis in patients with primary ITP during treatment with TPO‐RA.Methods:Multicenter retrospective study that included 121 adult primary ITP patients from 19 secondary and tertiary Spanish hospitals who had initiated treatment with Romiplostim (ROM) or Eltrombopag (ELT) as long‐term therapy between January 2012 and December 2014. Information on patient characteristics was collected from medical records to assess and compare risk factors of ITP patients with and without vascular events (VE).Results:A total of 121 patients (median age 63 years, range 19–96 years; 68% chronic phase), initiated TPO‐RA (ROM 54; EPG 67). During a 329.3 patient‐year time under treatment (exposure to ROM and ELT of 161.03 and 168.27 patient‐year, respectively) 15 patients experienced 17 vascular episodes (9 arterial, 8 venous). One patient presented antiphospholipid antibodies, five had been diagnosed with neoplasia, one with vascular peripheral disease, two with hypothyroidism –one of whom also had renal disease‐. Seven events occurred with ROM, and 10 with ELT. The annualized risk was 4.2 and 5.9 VE/100 patient‐years in ROM and ELT treated patients, respectively (median 5.2). Most VE occurred in the first year of TPO‐RA therapy (median 276 days; 5–1183), with a trend toward earlier events under ROM than ELT (127 days vs 360 days, respectively; p = 0.070). In the case of ischemic events the median time to arterial events was 165 vs. 606 days in ROM and ELT treated patients; P = 0.029. There were no significant differences in the 15 patients vs. the 106 patients that did not suffer from vascular events in terms of gender, age, diabetes, hypertension, previous vascular events, nor time on prednisone as 1st line therapy. In patients experiencing VE on TPO‐RA, a significant association with previous splenectomy (53.3% vs. 25.5%, P = 0.026), and chronic phase of the disease (93.3% vs. 64.1%, P = 0.024) compared with those not having such characteristic was detected. Surprisingly previous malignancy significantly associated with VE under TPO‐RA treatment (33% vs. 2.8%, P = 0.000009). All patients were reported to have sustained complete remission of previous neoplasias (1 colon carcinoma; 1 Burkitt lymphoma; 1 bladder cancer; 1 breast cancer; 1 patient with history of thyroid, breast and ovarian tumors) and were not receiving antineoplastic therapies. In multivariate analysis with logistic regression only previous malignancy predicted significantly higher odds of VE (Table 1).Summary/Conclusion:In this study, we describe an annualized risk of 5.2 vascular events/100 patient‐years in TPO‐RA treated patients. Venous and arterial thromboembolism are not frequent complications in ITP patients under TPO‐RA, except in particular settings, such as in splenectomized and chronic patients. Our data revealed a novel association of history of previous neoplasia with thrombotic events in patients with TPO‐RA. These results suggest that a history of prior cancer should be systematically screened before TPO‐RA initiation, and if so, alternative therapy should be considered; however, due to the limited sample size, further research is warranted.image

Background: High blood pressure is one of the four values used for monitoring a patient’s health condition. However, there are no reports on this parameter in relation to populations at different geographical altitudes. This study’s main objective was to determine the mean values of blood pressure according to patient characteristics and geographic altitude of residence in Peru. Methods: This was a multicenter, cross-sectional study, taken by convenience sampling. Patients lived for more than six months in cities with altitudes ranging from sea level to 5100 meters above mean sea level (mamsl). Data was categorized using 2000-m ranges and obtained from normotensive patients with hypertension (HTN) with and without treatment. P values were obtained using a multivariate analysis using Stata (Stata Corp, Texas, USA).Results: Of the 5,236 participants, 3,305(63%) were women, and the median age was 42 years. The median systolic/diastolic blood pressures (mmHg) were 110/70, 115.5/75, and 103/63, for 0-2000 mamsl, 2001-4000 mamsl, and 4001-5100 mamsl, respectively (p < 0.001). When data was adjusted according to patient characteristics, most of the differences in values were statistically significant for treated hypertensive (systolic p < 0.001; diastolic p = 0.243) and normotensive (systolic and diastolic p < 0.001), compared to untreated hypertensive patients. Conclusion: The blood pressure values varied with the altitude of residence and type of patient. Furthermore, these parameters should be taken into account as reference values by physicians working at different geographical altitudes for management of their patients.

Background:Thrombopoietin receptor agonists (TPO‐RA) are a well‐established treatment in patients with primary immune thrombocytopenia (ITP). Sustained treatment‐free responses (TFR) after TPO‐RA discontinuation in adult ITP have been reported; yet, to date there are no predictors to identify in which patients this approach is likely to be successful.Aims:To evaluate clinical predictors of TFR in a real world cohort of ITP patients treated with TPO‐RA.Methods:Patients aged >18 years with primary ITP who had initiated TPO‐RA (eltrombopag [EPG] or romiplostim [ROM]) treatment between January 2012 and December 2014 were included in this retrospective, multicenter study from 19 secondary and tertiary Spanish hospitals. Data on patient characteristics, history of disease and previous therapies, TPO‐RA administration, response and discontinuation were collected from medical records.Results:A total of 121 patients with a median age of 63 years (range 19–96 years), 59% females initiated TPO‐RA as long‐term therapy (ROM 54; EPG 67). Sixty‐eight percent of the patients treated with TPO‐RA met criteria for chronic, 16% for newly diagnosed and 16% for persistent ITP. The median time on TPO‐RA treatment was 35.2 months (1 to 67.3 months), and the median follow‐up from start of TPO‐RA until collection of data was 44.9 months (23.8 to 67.5 months). A total of 39 patients (32.2%) switched TPO‐RA during follow‐up. The most frequent cause for switching was lack of efficacy (48.7% of cases ‐in 89.5% the initial TPO‐RA was EPG‐). Due to switching the exposure to both TPO‐RAs was similar during follow‐up; 80 patients received ROM and a similar number was treated with EPG, with total exposure (years) of 161.0, and 168.3, respectively.During follow‐up almost one half of the patients (46.3%, n = 56) tapered‐off the TPO‐RA; 10 out of the 37 cases that discontinued ROM had previously received EPG, and 4 out of the 19 that stopped EPG had switched from ROM. After a median of 432 days (29–1344) under TPO‐RA treatment, 35 patients (28.9%) maintained TFR defined as platelet counts >50x109/l for more than 6 months. In 4 of these 35 cases, TPO‐RAs were reintroduced due to loss of response after a median TFR of 20.5 months. Potential predictors of TFR in the remaining 31 patients (25.6%) with sustained platelet counts in the absence of any agent meant to increase platelet count (median 32 months, 8–217) were analyzed. No specific patient feature (e.g. age, comorbidities, ITP duration, previous treatments), bleeding, previous therapies nor phase of disease seemed to consistently predict for sustained response off therapy. However, univariate analysis (Chi‐square) did identify statistically significant predictors of TFR. Interestingly, while the specific TPO‐RA that was discontinued did not influence the probability to achieve TFR, receiving ROM as first TPO‐RA was positively associated with TFR (P = 0.010), while switching TPO‐RA negatively predicted sustained platelet responses (P = 0.002). In multivariate analysis with logistic regression both variables predicted significantly higher odds of TFR (Table 1).Summary/Conclusion:Platelet response following TPO‐RA cessation is sustained in 25.6% of adult patients with primary ITP. Although published studies have not identified a predictive factor of sustained response after TPO‐RA discontinuation, in this long‐term follow up analysis, ROM as first TPO‐RA being administered, and no need of TPO‐RA switching are factors that positively correlate with the probability to achieve TFR.image

Background: Recently a range of alternative novel therapies have been developed to improve treatment options for patients with Hemophilia A. One approach is to generate a Factor VIII (F.VIII) mimetic molecule using a humanised bispecific antibody, as was done for Hemlibra. Taking advantage of Kymab's fully human antibody discovery platform, we describe the selection and optimisation of an FVIII mimetic common light chain (CLC) bispecific antibody which can similarly catalyse the generation of Factor Xa (FXase) and normalise the activated partial thromboplastin time (aPTT).Aims: To generate a functionally active F.VIII mimetic bispecific antibody for Haemophilia A treatment Methods: F.IX and F.X. binding antibodies were generated by immunizing Kymouse ® , which contain the full human immunoglobin repertoire, with F.IX or F.X, respectively. Isolated F.IX and F.X specific arms were co-expressed as 2-heavy-2-light-chain (2H2L) bispecific antibodies. Purified 2H2L bispecifics were screened using a high-throughput chromogenic FXase assay. The light chain of a promiscuous F.IX arm was chosen to generate transgenic mice expressing this bespoke common light chain (CLC) in the Kymouse ® background. By immunizing these transgenic mice with F.X, F.X binding antibodies containing the CLC were recovered. The heavy chains of these F.X binding antibodies were co-expressed with the heavy/light chains of the chosen F.IX arm as CLC bispecific antibodies. One biologically active CLC bispecific antibody was identified by functional assays, and chosen for further optimization. The optimization of the lead bispecific antibody, KY1049, was achieved by data mining of next generation sequencing information using Kymab's IntelliSelect ® bioinformatic platform, coupled with site-specific mutagenesis. Results: More than 8,000 2H2L bispecifics were screened by a chromogenic FXase assay to select the most active and versatile F.IX arm (Figure 1A). More than 400 F.X heavy chains subsequently isolated from the bespoke CLC Kymouse ® were screened to identify a highly active CLC bispecific (Figure 1B). Further optimisation of the molecule was carried out to iteratively increase FVIII mimetic activity by deep data-mining of heavy chain NGS sequence data, or site-specific mutagenesis. The combinatorial optimization process resulted in a highly functional CLC bispecific, KY1049 with comparable F.VIII mimetic activities to a sequence-identical analogue of Hemlibra (Figure 1C). Summary/Conclusion:Our bispecific antibody discovery platform consisting of four-chain matrix screening, common light chain transgenic mouse technology, B cell network analysis and site-specific mutagenesis was applied to develop KY1049, a potent FV.III mimetic bispecific antibody, which shows equivalent activity to Hemlibra in vitro and holds promise as a future therapeutic in Haemophilia A.