[Iliac aneurysm rupture during preconditioning with levosimendan for coronary artery bypass graft]

We present the case of a 77 year-old patient scheduled for coronary artery bypass. During the infusion of levosimendan as preconditioning for surgery, a rupture of right common iliac artery occurred. Surgery was delayed and an urgent aorto-bifemoral bypass was performed. We believe that the rupture of the artery was triggered by an increase in transmural pressure due to the inotropic effects of levosimendan in a dilated diseased vessel. To our knowledge, there are no cases of aneurysm rupture as a complication during levosimendan infusion, but the coincidence of events in time strongly suggests some kind of causal relationship.

FDA OK's Iclusig's return to market

With new safety measures in place, the U.S. Food and Drug Administration will allow Ariad Pharmaceuticals to resume marketing Iclusig, sales of which were suspended in October 2013.

Randomised study to assess the efficacy and safety of once-daily etravirine-based regimen as a switching strategy in HIV-infected patients receiving a protease inhibitor-containing regimen. Etraswitch study

Background

Etravirine (ETR) was approved for patients with virological failure and antiretroviral resistance mutations. It has also shown antiviral efficacy in antiretroviral-naïve patients. However, data on the switching from protease inhibitors (PI) to ETR are lacking.

Methods

HIV-1-infected patients with suppressed viral load (VL) during a PI-containing regimen (>12 months) and no previous virological failure were randomized to switch from the PI to ETR (400 mg/day, dissolved in water) (ETR group, n = 22) or to continue with the same regimen (control group, n = 21). Percentage of patients with VL≤50 copies/mL were assessed at week 48, as well as changes in CD4 T-cell counts and metabolic profile.

Results

We included 43 patients [72.9% male, 46.3 (42.2; 50.6) years]. Two patients receiving ETR (grade-1 diarrhea and voluntary discontinuation) and another in the control group (simplification) discontinued therapy early. No patients presented virological failure (two consecutive VL>50 copies/mL); treatment was successful in 95.2% of the control group and 90.9% of the ETR group (intention-to-treat analysis, missing = failure) (p = 0.58). CD4+ T-cell counts did not significantly vary [+49 cells/µL in the ETR group (p = 0.25) and −4 cells/µL in the control group (p = 0.71)]. The ETR group showed significant reductions in cholesterol (p<0.001), triglycerides (p = <0.001), and glycemia (p = 0.03) and higher satisfaction (0–10 scale) (p = 0.04). Trough plasma concentrations of ETR were similar to observed in studies using ETR twice daily.

Conclusion

Switch from a PI-based regimen to a once-daily combination based on ETR maintained undetectable VL during 48 weeks in virologically suppressed HIV-infected patients while lipid profile and patient satisfaction improved significantly.

Trial Registration

ClinicalTrials.gov NCT01034917

Bilateral cotton wool spots after use of an endothelin receptor antagonist

Ambrisentan (Letairis; Gilead Sciences, Foster City, CA) is an endothelin receptor antagonist approved by the U.S. Food and Drug Administration for the treatment of pulmonary arterial hypertension. The authors describe the occurrence of bilateral cotton wool spots soon after initiation of ambrisentan treatment in a 29-year-old woman. Fluorescein angiography, optical coherence tomography, and fundus autofluorescence were performed. After discontinuation of ambrisentan, the cotton wool spots resolved without recurrence. To the authors' knowledge, this is the first report of retinopathy in the form of cotton wool spots associated with the use of an endothelin receptor antagonist.

Ariad suspends ponatinib sales

Because of concerns about serious cardiovascular side effects, the U.S. Food and Drug Administration asked Ariad Pharmaceuticals to temporarily suspend sales and marketing of ponatinib to treat chronic myeloid leukemia in patients resistant to first-line therapy.

A phase 2 trial of ponatinib in Philadelphia chromosome-positive leukemias

BACKGROUND

Ponatinib is a potent oral tyrosine kinase inhibitor of unmutated and mutated BCR-ABL, including BCR-ABL with the tyrosine kinase inhibitor-refractory threonine-to-isoleucine mutation at position 315 (T315I). We conducted a phase 2 trial of ponatinib in patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL).

METHODS

We enrolled 449 heavily pretreated patients who had CML or Ph-positive ALL with resistance to or unacceptable side effects from dasatinib or nilotinib or who had the BCR-ABL T315I mutation. Ponatinib was administered at an initial dose of 45 mg once daily. The median follow-up was 15 months.

RESULTS

Among 267 patients with chronic-phase CML, 56% had a major cytogenetic response (51% of patients with resistance to or unacceptable side effects from dasatinib or nilotinib and 70% of patients with the T315I mutation), 46% had a complete cytogenetic response (40% and 66% in the two subgroups, respectively), and 34% had a major molecular response (27% and 56% in the two subgroups, respectively). Responses were observed regardless of the baseline BCR-ABL kinase domain mutation status and were durable; the estimated rate of a sustained major cytogenetic response of at least 12 months was 91%. No single BCR-ABL mutation conferring resistance to ponatinib was detected. Among 83 patients with accelerated-phase CML, 55% had a major hematologic response and 39% had a major cytogenetic response. Among 62 patients with blast-phase CML, 31% had a major hematologic response and 23% had a major cytogenetic response. Among 32 patients with Ph-positive ALL, 41% had a major hematologic response and 47% had a major cytogenetic response. Common adverse events were thrombocytopenia (in 37% of patients), rash (in 34%), dry skin (in 32%), and abdominal pain (in 22%). Serious arterial thrombotic events were observed in 9% of patients; these events were considered to be treatment-related in 3%. A total of 12% of patients discontinued treatment because of an adverse event.

CONCLUSIONS

Ponatinib had significant antileukemic activity across categories of disease stage and mutation status. (Funded by Ariad Pharmaceuticals and others; PACE ClinicalTrials.gov number, NCT01207440 .).

[Efficacy and safety of ambrisentan therapy in Chinese patients with pulmonary hypertension]

OBJECTIVE

To explore the efficacy, safety and tolerance of ambrisentan, a high-selective endothelin receptor antagonist, in Chinese patients with pulmonary hypertension (PH).

METHODS

Twenty-eight PH patients (Group 1+Group 4) came from Shanghai East Hospital, Zhongshan Hospital of Fudan University and Fifth People's Hospital of Shanghai were recruited into this open-label, prospective multi-center trial between August 2012 and February 2013. They received 2.5-5.0 mg ambrisentan once daily for 12 weeks. The primary endpoint was the change in exercise capacity showed by six-minute walk distance (6MWD) from baseline to 12 weeks. Secondary endpoints included the changes in World Health Organization (WHO) function class, N-terminal brain natriuretic peptide (NT-proBNP) and liver function test results.

RESULTS

There were 9 males and 19 females with an average age of (35 ± 17) years. The value of 6MWD increased from (372 ± 86) m at baseline to (443 ± 96) m (P = 0.000) after 12 weeks. WHO functional class improved after a 12-week therapy compared to the baseline level (P = 0.000). NT-proBNP decreased from a median of 732 ng/L at baseline to 329 ng/L after 12 weeks (P = 0.046). The baseline liver function test was normal. And liver function test didn't significantly change after a 12-week therapy.

CONCLUSION

Ambrisentan therapy is well-tolerated and it improves the exercise capacity and WHO function class in Chinese PH patients.

[Efficiency of initiation with ambrisentan versus bosentan in the treatment of pulmonary arterial hypertension]

OBJECTIVE

To evaluate the efficiency of initiation with endothelin receptor antagonists, ambrisentan or bosentan, followed by sequential combination with phosphodiesterase-5 inhibitors and prostanoids in the treatment of pulmonary arterial hypertension, from the Spanish National Health System perspective.

METHODS

A Markov model was developed based on the four New York Heart Association functional classes. A panel of three experts reached a consensus on patient management based on clinical practice. Patients revised their treatment every 12 weeks, based on their health status and previous medication records. Pharmacological treatment costs and costs associated with very frequent adverse events (AE) were considered in a horizon of 60 weeks. Outcomes were measured in qualityadjusted life years (QALY). A probabilistic sensitivity analysis was performed.

RESULTS

No clinically relevant differences in QALY per-patient and year were found for initiation with ambrisentan and bosentan: 0.6853 and 0.6902, respectively. Initiation with ambrisentan resulted in lower pharmacological treatment and AE management costs: ?35,550 and ?117 versus ?40,224 and ?171. In the sensitivity analysis, initiation with ambrisentan resulted in a negative significant cost difference: ?-4,982; CI95%[?- 8,014; ?-2,500]; while no significant differences in QALY were found: -0.0044; CI95%[-0.0189; 0.0101].

CONCLUSIONS

Initiation with ambrisentan followed by sequential combination with phosphodiesterase-5 inhibitors and prostanoids yields comparable outcomes at lower costs than initiation with bosentan.

Analysis of the potential effect of ponatinib on the QTc interval in patients with refractory hematological malignancies

Purpose

Cardiac dysfunction, particularly QT interval prolongation, has been observed with tyrosine kinase inhibitors approved to treat chronic myeloid leukemia. This study examines the effects of ponatinib on cardiac repolarization in patients with refractory hematological malignancies enrolled in a phase 1 trial.

Methods

Electrocardiograms (ECGs) were collected at 3 dose levels (30, 45, and 60 mg) at 6 time points. Electrocardiographic parameters, including QTc interval, were measured, and 11 morphological analyses were conducted. Central tendency analyses of ECG parameters were performed using time-point and time-averaged approaches. All patients with at least 2 baseline ECGs and 1 on-treatment ECG were included in the analyses. Patients with paired ECGs and plasma samples were included in the pharmacokinetic/pharmacodynamic analysis to examine the relationship between ponatinib plasma concentration and change from baseline in QT intervals.

Results

Thirty-nine patients at the 30-, 45-, and 60-mg dose levels were included in the central tendency and morphological analyses. There was no significant effect on cardiac repolarization, as evidenced by non-clinically significant mean QTcF changes from baseline of −10.9, −3.6, and −5.0 ms for the 30-, 45-, and 60-mg dose levels, respectively. The morphological analysis revealed 2 patients with atrial fibrillation and 2 with T wave inversion. Seventy-five patients were included in the pharmacokinetic/pharmacodynamic analysis across all dose levels. The slope of the relationship for QTcF versus plasma ponatinib concentration was not positive (−0.0171), indicating no exposure–effect relationship.

Conclusions

Ponatinib is associated with a low risk of QTc prolongation in patients with refractory hematological malignancies.

Hepatoxicity of new antiretrovirals: a systematic review

There has been a major paradigm shift in the management of HIV infected patients, with earlier initiation of antiretroviral treatment and lifelong exposure to drugs for which long-term safety issues must be faced by clinicians. Within the past 5 years, new drugs from both previously established and novel therapeutic classes have been released that tend to be safer and more efficient than their former combinations. Although hepatotoxicity was one of the most common side effects from initial antiretrovirals, phase II/III safety data regarding liver tolerance from more recent drugs are reassuring. However, data on the long-term exposure to these therapeutic options are needed, and a handful of case reports are emerging, reporting rare but potentially life-threatening adverse hepatic events in patients with hepatitis co-infection or taking other hepatotoxic drugs.

Levosimendan: Implications for Clinicians

Levosimendan is a novel calcium sensitizing agent in development for the treatment of acute and chronic heart failure. The agent increases myocardial force without increasing myocyte calcium concentrations, thus reducing the possibility for myocardial necrosis. In addition, the agent also causes vasodilation of coronary and peripheral vessels to improve coronary blood flow and reduce afterload. The short half-life is a benefit for intravenous administration but could be problematic for the drug's use in chronic heart failure. The risk of the development of arrhythmias from levosimendan appears small secondary to an increase in the QTc interval of 15 msec but needs to be evaluated in light of the ability of levosimendan to open adenosine triphosphate (ATP)-sensitive potassium channels. In addition, the agent has not been studied in patients with additional risks for torsades de pointes. Levosimendan has been shown to have beneficial survival effects in several populations; its use improves patient outcomes relative to the standard of care and has the potential to reduce hospital costs associated with heart failure.

Ponatinib in refractory Philadelphia chromosome-positive leukemias

BACKGROUND

Resistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) is frequently caused by mutations in the BCR-ABL kinase domain. Ponatinib (AP24534) is a potent oral tyrosine kinase inhibitor that blocks native and mutated BCR-ABL, including the gatekeeper mutant T315I, which is uniformly resistant to tyrosine kinase inhibitors.

METHODS

In this phase 1 dose-escalation study, we enrolled 81 patients with resistant hematologic cancers, including 60 with CML and 5 with Ph-positive ALL. Ponatinib was administered once daily at doses ranging from 2 to 60 mg. Median follow-up was 56 weeks (range, 2 to 140).

RESULTS

Dose-limiting toxic effects included elevated lipase or amylase levels and pancreatitis. Common adverse events were rash, myelosuppression, and constitutional symptoms. Among Ph-positive patients, 91% had received two or more approved tyrosine kinase inhibitors, and 51% had received all three approved tyrosine kinase inhibitors. Of 43 patients with chronic-phase CML, 98% had a complete hematologic response, 72% had a major cytogenetic response, and 44% had a major molecular response. Of 12 patients who had chronic-phase CML with the T315I mutation, 100% had a complete hematologic response and 92% had a major cytogenetic response. Of 13 patients with chronic-phase CML without detectable mutations, 100% had a complete hematologic response and 62% had a major cytogenetic response. Responses among patients with chronic-phase CML were durable. Of 22 patients with accelerated-phase or blast-phase CML or Ph-positive ALL, 36% had a major hematologic response and 32% had a major cytogenetic response.

CONCLUSIONS

Ponatinib was highly active in heavily pretreated patients with Ph-positive leukemias with resistance to tyrosine kinase inhibitors, including patients with the BCR-ABL T315I mutation, other mutations, or no mutations. (Funded by Ariad Pharmaceuticals and others; ClinicalTrials.gov number, NCT00660920.).

[Retrospective descriptive study about the use of levosimendan in children undergoing surgical correction for congenital heart disease]

OBJECTIVES

To describe the use of levosimendan for compassionate use in children undergoing surgery for congenital heart disease, as well as survival rates, and the variations in the haemodynamic and analytical variables studied.

MATERIAL AND METHODS

An observational retrospective descriptive study was performed, using a review of clinical histories, from May 2005 to January 2010. Haemodynamic and analytical variables pre- and post- levosimendan administration, drugs used, and their dosages, and any adverse reactions were recorded.

RESULTS

Forty two children, 38 of them undergoing surgical correction, between the ages of four days and 5.75 years (median 92 days) were included. The drug was infused on 46 occasions. Four children received two doses. The infusion rate was among 0.1 to 0.6 μg × kg⁻¹ × min⁻¹. Only one patient received a loading dose. In 15 administrations (32.6%), the same dose was maintained throughout the infusion period. In 19 cases (41.3%), the dose was increased or decreased according to the need for vasoactive support. In surgical patients, overall survival after 30 days of the administration, calculated using the Kaplan-Meier method, was 80%. Blood lactate levels were statistically associated with mortality (P<.001).

CONCLUSIONS

There were no uniform criteria for using levosimendan, and it was only used as a rescue drug. Overall survival was similar to that reported in adult clinical trials. Clinical trials also need to be carried out in paediatric patients to determine the role of levosimendan in surgical practice, in order to develop and establish a clinical protocol for its use in children.

Long-term safety and efficacy of ambrisentan in Japanese adults with pulmonary arterial hypertension

OBJECTIVE

To investigate the safety and efficacy of long-term administration of ambrisentan in Japanese adults with pulmonary arterial hypertension (PAH).

RESEARCH DESIGN AND METHODS

In this open-label extension of a preceding multicenter dose-escalation study, 21 Japanese patients with PAH received treatment with 5 or 10 mg of ambrisentan once daily and were comprehensively evaluated every 12 weeks. The primary endpoint was the safety of long-term ambrisentan administration, as defined by the incidence and severity of adverse events. The secondary (efficacy) endpoints were change in exercise capacity (as indicated by 6-minute walk distance), World Health Organization functional class, Borg dyspnea index, plasma brain natriuretic peptide level, cardiopulmonary hemodynamics, and time to clinical worsening of PAH.

CLINICAL TRIAL REGISTRATION

NCT00554619.

RESULTS

The mean total duration of treatment (i.e., including the preceding dose-escalation study) was approximately 139 weeks. There were fewer adverse events related to ambrisentan in this study than in the preceding study, and we identified no new safety signals that might preclude the long-term use of ambrisentan among Japanese adults with PAH. Improvements observed in efficacy endpoints in the preceding study were maintained in the present study.

LIMITATIONS

This study did not include a control group and lacked the statistical power to reach definite conclusions regarding the efficacy of ambrisentan.

CONCLUSION

Our results suggest that long-term administration of ambrisentan is well tolerated and efficacious for Japanese adults with PAH.

Pharmacological characterization of A-960656, a histamine H₃ receptor antagonist with efficacy in animal models of osteoarthritis and neuropathic pain

Histamine H(3) receptor antagonists have been widely reported to improve performance in preclinical models of cognition, but more recently efficacy in pain models has also been described. Here, A-960656 ((R)-2-(2-(3-(piperidin-1-yl)pyrrolidin-1-yl)benzo[d]thiazol-6-yl)pyridazin-3(2H)-one) was profiled as a new structural chemotype. A-960656 was potent in vitro in histamine H(3) receptor binding assays (rat K(i)=76 nM, human K(i)=21 nM), and exhibited functional antagonism in blocking agonist-induced [(35)S]GTPγS binding (rat H(3) K(b)=107 nM, human H(3) K(b)=22 nM), and was highly specific for H(3) receptors in broad screens for non-H(3) sites. In a spinal nerve ligation model of neuropathic pain in rat, oral doses of 1 and 3mg/kg were effective 60 min post dosing with an ED(50) of 2.17 mg/kg and a blood EC(50) of 639 ng/ml. In a model of osteoarthritis pain, oral doses of 0.1, 0.3, and 1mg/kg were effective 1h post dosing with an ED(50) of 0.52 mg/kg and a blood EC(50) of 233 ng/ml. The antinociceptive effect of A-960656 in both pain models was maintained after sub-chronic dosing up to 12 days. A-960656 had excellent rat pharmacokinetics (t(1/2)=1.9h, 84% oral bioavailability) with rapid and efficient brain penetration, and was well tolerated in CNS behavioral safety screens. In summary, A-960656 has properties well suited to probe the pharmacology of histamine H(3) receptors in pain. Its potency and efficacy in animal pain models provide support to the notion that histamine H(3) receptor antagonists are effective in attenuating nociceptive processes.

The afterhyperpolarizing potential following a train of action potentials is suppressed in an acute epilepsy model in the rat Cornu Ammonis 1 area

In hippocampal Cornu Ammonis 1 (CA1) neurons, a prolonged depolarization evokes a train of action potentials followed by a prominent afterhyperpolarizing potential (AHP), which critically dampens neuronal excitability. Because it is not known whether epileptiform activity alters the AHP and whether any alteration of the AHP is independent of inhibition, we acutely induced epileptiform activity by bath application of the GABA(A) receptor blocker gabazine (5 μM) in the rat hippocampal slice preparation and studied its impact on the AHP using intracellular recordings. Following 10 min of gabazine wash-in, slices started to develop spontaneous epileptiform discharges. This disinhibition was accompanied by a significant shift of the resting membrane potential of CA1 neurons to more depolarized values. Prolonged depolarizations (600 ms) elicited a train of action potentials, the number of which was not different between baseline and gabazine treatment. However, the AHP following the train of action potentials was significantly reduced after 20 min of gabazine treatment. When the induction of epileptiform activity was prevented by co-application of 6-cyano-7-nitroquinoxaline-2,3-dione disodium (CNQX, 10 μM) and D-(-)-2-amino-5-phosphonopentanoic acid (D-AP5, 50 μM) to block α-amino-3-hydroxy-5-methylisoxazolepropionate (AMPA) and N-methyl-d-aspartate (NMDA) receptors, respectively, the AHP was preserved despite of GABA(A) receptor inhibition suggesting that the epileptiform activity was required to suppress the AHP. Moreover, the AHP was also preserved when the slices were treated with the protein kinase blockers H-9 (100 μM) and H-89 (1 μM). These results demonstrate that the AHP following a train of action potentials is rapidly suppressed by acutely induced epileptiform activity due to a phosphorylation process-presumably involving protein kinase A.

[Possibilities of using levosimendan in patients with idiopathic pulmonary hypertension]

AIM

To evaluate the efficiency and safety of intravenous infusion of levosimendan in patients with idiopathic pulmonary hypertension (IPH) and its clinical, hemodynamic, and neurohumoral effects.

SUBJECTS AND METHODS

The study included 9 patients (mean age 31.8 +/- 8.7 years) with Functional Class III and IV IPH and severe right ventricular failure (RVF). Levosimendan was administered as dropwise intravenous infusion. The patients' general condition, blood pressure, heart rate, and 6-minute walk test results were assessed at baseline and 24 hours after levosimendan infusion, and then following 12 weeks. The time course of changes in blood neurohumoral mediators was determined and transthoracic echocardiography performed.

RESULTS

At 24 hours after initiation of levosimendan infusion, there were substantial reductions in pulmonary artery systolic pressure, mean pulmonary artery pressure, mean right atrial pressure, and pulmonary vascular resistance. There was a significant increase in exercise tolerance. The blood exhibited lower norepinephrine and NT-proBNP and higher epinephrine concentrations. At 12 weeks after termination of levosimendan infusion, the improved functional status was preserved in the patients with IPH. There were no noticeable changes in the achieved key hemodynamic parameters. Only one patient needed re-administration of the drug 12 weeks later. The achieved changes in vasoactive mediators were retained 12 weeks following levosimendan infusion. Levosimendan treatment was not followed by clinically relevant adverse reactions requiring infusion termination and therapy discontinuation.

CONCLUSION

24-hour intravenous levosimendan infusion in patents with FC III-IV IPH and severe RVF causes positive changes in the key hemodynamic parameters and neurohumoral status of the patients and promotes stabilization in those with IPH at 12-week follow-up.