Overall safety of relamorelin in adults with diabetic gastroparesis: Analysis of phase 2a and 2b trial data

BACKGROUND

Relamorelin, a pentapeptide ghrelin receptor agonist, accelerated gastric emptying significantly and improved symptoms in adults with diabetic gastroparesis in phase 2 trials.

AIM

To assess the safety and tolerability of relamorelin across phase 2 trials.

METHODS

Safety assessments in patients aged 18-75 years (weight, adverse events [AEs] and laboratory tests) from two randomised, double-blind phase 2 trials (NCT01571297, NCT02357420; results published previously) were reviewed descriptively. Analysis of covariance assessed treatment effect on glycated haemoglobin (HbA1c) and blood glucose post hoc. Phase 2a and 2b trial durations were, respectively, 4 weeks (relamorelin 10 µg once or twice daily [b.d.] or placebo b.d.) and 12 weeks (relamorelin 10, 30 or 100 µg or placebo b.d.) with 1- and 2-week, single-blind placebo run-ins.

RESULTS

Among 204 phase 2a and 393 phase 2b patients, respectively, 67% and 62% were female, and 88% and 89% had type 2 diabetes. Proportions of patients reporting serious AEs were similar across treatment groups, as were those with ≥1 treatment-emergent AE (TEAE). TEAE-related discontinuations were proportionally higher in relamorelin groups than placebo. Of 12 serious TEAEs in phase 2a, none occurred in >1 patient. In phase 2b, five serious TEAEs were reported in >1 patient, and one (100 µg) died (urosepsis), all unrelated to relamorelin. In phase 2b, increased HbA1c and fasting blood glucose levels were dose-related (P < 0.0001 and P = 0.0043, respectively).

CONCLUSIONS

Relamorelin showed acceptable safety and tolerability in phase 2 trials. Relamorelin may elevate blood glucose: this should be managed proactively in relamorelin-treated patients.

Evaluation of Cardiac Toxicity Biomarkers in Rats from Different Laboratories

There is a great need for improved diagnostic and prognostic accuracy of potential cardiac toxicity in drug development. This study reports the evaluation of several commercially available biomarker kits by 3 institutions (SRI, Eli Lilly, and Pfizer) for the discrimination between myocardial degeneration/necrosis and cardiac hypertrophy as well as the assessment of the interlaboratory and interplatform variation in results. Serum concentrations of natriuretic peptides (N-terminal pro-atrial natriuretic peptide [NT-proANP] and N-terminal pro-brain natriuretic peptide [NT-proBNP]), cardiac and skeletal troponins (cTnI, cTnT, and sTnI), myosin light chain 3 (Myl3), and fatty acid binding protein 3 (FABP3) were assessed in rats treated with minoxidil (MNX) and isoproterenol (ISO). MNX caused increased heart-to-body weight ratios and prominent elevations in NT-proANP and NT-proBNP concentrations detected at 24-hr postdose without elevation in troponins, Myl3, or FABP3 and with no abnormal histopathological findings. ISO caused ventricular leukocyte infiltration, myocyte fibrosis, and necrosis with increased concentrations of the natriuretic peptides, cardiac troponins, and Myl3. These results reinforce the advantages of a multimarker strategy in elucidating the underlying cause of cardiac insult and detecting myocardial tissue damage at 24-hr posttreatment. The interlaboratory and interplatform comparison analyses also showed that the data obtained from different laboratories and platforms are highly correlated and reproducible, making these biomarkers widely applicable in preclinical studies.