It is an open question if these

It is an open question if these in vitro findings have implications for the use of sGC activators in the in vivo situation and in patients. Assuming that incorporation in de novo synthesised enzyme occurs during therapy, one might speculate that the duration of drug administration has an influence on the induced effect in addition to the overall dose. The longer the time of drug administration, the higher the number of de novo synthesised enzyme during drug exposure. There are at least two long-term animal studies on cinaciguat published showing beneficial effects of orally administered long-term treatment with sGC activators: In the first study cinaciguat treatment over 18 weeks in an experimental model of chronic kidney disease effectively prevented the increase in blood pressure, reduced left ventricular hypertrophy and slowed renal disease progression in rats with 5/6 nephrectomy by targeting mainly oxidized/heme free NOsGC [45]. In the second study, cinaciguat was investigated in an experimental model of salt-sensitive hypertension, a condition that is associated with increased oxidative stress, heme loss from NOsGC and development of chronic renal failure [46]. In Dahl/ss rats on a high salt diet cinaciguat markedly improved survival, improved renal function and ameliorated the salt-induced increase in blood pressure. Taken together, these animal studies show that long-term activation of heme-free NOsGC leads to renal protection in experimental models of hypertension and chronic kidney disease and underline the promising potential of cinaciguat by targeting the disease associated heme-free form of NOsGC. Unfortunately, it has not been investigated in these long-term animal studies, to what extent the incorporation in de novo synthesised enzyme occurs during therapy and whether the duration of drug administration has an influence in addition to the overall dose. Cinaciguat was tested in animal models of congestive Kifunensine failure, coronary artery disease and renal insufficiency. In dogs with congestive heart failure, intravenous cinaciguat led to a decrease in cardiac preload and afterload, and an increase in cardiac ejection fraction [47]. In patients with acute decompensated heart failure, intravenous infusion of cinaciguat for a maximum of 6 h improved cardiopulmonary hemodynamics without drug related serious adverse events (phase IIa study) [48]. Based on this success cinaciguat was tested in the placebo controlled, randomized, double-blind COMPOSE 1 and 2 and COMPOSE EARLY (phase IIb) studies in patients with acute decompensated heart failure [49]. A notable difference to the phase IIa study was an increase in infusion time to 24–48 h. Because of an increase in non-fatal hypotension and difficulties to recruit patients COMPOSE was discontinued. In summary, we present for the first time an experimental strategy of complete heme removal and replacement by activator without unspecific manipulation of the NOsGC enzyme: addition of activator to the expression system. The introduced method is a helpful tool for investigation of activator kinetics as well as crystallization trials. Through the new expression with activator approach, we showed a significant stimulation of the α2/β1 isoform by both cinaciguat and BAY 60–2770. We could confirm the higher efficacy of BAY 60–2770 compared to cinaciguat [14] and show that this is also true for the α2/β1 isoform. Moreover, we postulate that replacement of NOsGC ferric heme in tissue under oxidative stress might require careful dose-adaptation depending on treatment duration and pharmacokinetics of the used sGC activator.
Acknowledgments
Introduction Antibody–drug-conjugates (ADCs), or immunoconjugates, are a novel and relatively new class of anti-cancer treatment (Smaglo et al., 2014, Casi and Neri, 2015). This class of drug is comprised of an antibody, a linker, and the therapeutic agent. The antibody is able to recognize cancer antigens with high specificity, while the linker ensures that the therapeutic agent remains attached to the antibody until it reaches the specific tumor target. These drugs are designed to deliver a potent therapeutic entity directly to the tumor sparing the normal tissues.