AOP Orphan (Austria)

Polycythemia vera is characterized by the acquisition of the JAK2V617F mutation. Recommended treatments include hydroxyurea and interferon-alpha. Several groups have reported a reduction in the JAK2 mutant allele burden in interferon-treated patients, but significance of this observation is questioned. We characterized the activity of ropeginterferon alpha-2b, a novel form of interferon-alpha recently shown to be safe and efficacious in polycythemia vera. Ropeginterferon was able to inhibit the proliferation of the HEL, UKE-1, and UT-7 JAK2-mutant cell lines while sparing JAK2-wild-type UT-7 and normal CD34+ cells growth. In vitro treatment of erythroid progenitors derived from PV patients showed that ropeginterferon could considerably inhibit the growth of endogenous erythroid colonies, a hallmark of polycythemia vera. Finally, we could study in sequential samples the clonal architecture of erythroid progenitors derived from patients included in a randomized study comparing hydroxyurea to ropeginterferon. After 1 year of treatment with ropeginterferon, the ratio of JAK2-mutated to wild-type colonies grown from bone marrow progenitors was reduced by 64%, compared to 25% in patients receiving hydroxyurea. This study shows that ropeginterferon has a potent targeted activity against JAK2-mutant cells and is able to drastically reduce the proportion of malignant progenitors in patients treated with this drug.

We developed a novel analytical method for concentration determination of tandem single‐chain antibody diphtheria toxin (immunotoxin). The method is based on polymethacrylate monoliths with Protein L ligands as the binding moiety. Different buffers were tested for elution of the Protein L‐bound immunotoxin and 4.5 M guanidinium hydrochloride performed best. We optimized the elution conditions and the method sequence resulting in a fast and robust method with a runtime <10 min. Fast determination of immunotoxin is critical if any process decisions rely on this data. We determined method performance and a lower limit of detection of 27 μg/mL and a lower limit of quantification of 90 μg/mL was achieved. The validity of the method in terms of residual analysis, precision, and repeatability was proven in a range from 100 to 375 μg/mL. The short runtime and ease of use of a high‐performance liquid chromatography method is especially useful for a process analytical tool approach. Bioprocesses related to immunotoxin where fermentation or other process parameters can be adjusted in accordance to the immunotoxin levels will be benefited from this method to achieve the highest possible purity and productivity.

The aim of this prospective study was to compare in non-Asian subjects the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of two short-acting cardioselective β1-adrenergic antagonists, landiolol and esmolol, after administration of three different bolus dosages. We conducted a single-center, prospective, double-blinded, randomized study in three cross-over periods with 12 healthy subjects (7 women and 5 men, mean age of 24.5±6.9years) each receiving three doses of landiolol (0.1, 0.2, and 0.3mg/kg BW) either in a newly developed concentrate i.v. formulation (Rapibloc® 20mg/2mL concentrate) or a lyophilized formulation, or three doses of esmolol (0.5, 1, and 1.5mg/kg BW) in an i.v. formulation (Brevibloc® 100mg/10mL). PK and PD parameters, safety, and tolerability were assessed. Results of the two landiolol formulations were reported previously and were similar. For the landiolol concentrate formulation and esmolol, maximum blood concentrations were rapidly reached (mean t max ranged between 1.8 and 3.0min for landiolol and 1.8 to 2.4min for esmolol). The parent drugs disappeared very fast from the blood stream, with a t 1/2 of 3.2±1.2 (SD) minutes and 3.7±2.1 (SD) minutes for the low doses of landiolol and esmolol, respectively. Despite comparable injection rates (0.1 or 0.5mg/kg/15s for landiolol and esmolol, respectively), the onset of significant heart rate reduction occurred earlier in response to landiolol (1min) than in response to esmolol (2min). In addition, significantly lower heart rate values were obtained at every dose level of landiolol, in comparison to esmolol (p<0.05). Both compounds reduced the systolic blood pressure to a comparable degree. Especially at the highest dose, the duration of blood pressure reduction was longer under esmolol compared to landiolol. Seven mild to moderate adverse events occurred after administration of landiolol, and five occurred after administration of esmolol. No serious adverse events were reported in this study. Heart rate reduction induced by a new liquid formulation of landiolol occurred faster, was more pronounced, and lasted longer than the effects of corresponding standard esmolol doses. Both agents reduced systolic blood pressure to a comparable degree, but the blood pressure decrease lasted longer after esmolol infusion. The local tolerance and safety profiles of the two formulations were similar. In summary, compared to esmolol, landiolol shows a more prominent and pronounced bradycardic effect in relation to its blood pressure-lowering effect, an action profile that might be of specific advantage in the perioperative setting. NCT01652898 and 2012-002127-14. https://clinicaltrials.gov/ct2/show/NCT01652898?term=landiolol&rank=7.