Systemic administration of PRO051 in Duchenne's muscular dystrophy.

BACKGROUND: Local intramuscular administration of the antisense oligonucleotide PRO051 in patients with Duchenne's muscular dystrophy with relevant mutations was previously reported to induce the skipping of exon 51 during pre-messenger RNA splicing of the dystrophin gene and to facilitate new dystrophin expression in muscle-fiber membranes. The present phase 1-2a study aimed to assess the safety, pharmacokinetics, and molecular and clinical effects of systemically administered PRO051. METHODS: We administered weekly abdominal subcutaneous injections of PRO051 for 5 weeks in 12 patients, with each of four possible doses (0.5, 2.0, 4.0, and 6.0 mg per kilogram of body weight) given to 3 patients. Changes in RNA splicing and protein levels in the tibialis anterior muscle were assessed at two time points. All patients subsequently entered a 12-week open-label extension phase, during which they all received PRO051 at a dose of 6.0 mg per kilogram per week. Safety, pharmacokinetics, serum creatine kinase levels, and muscle strength and function were assessed. RESULTS: The most common adverse events were irritation at the administration site and, during the extension phase, mild and variable proteinuria and increased urinary α(1)-microglobulin levels; there were no serious adverse events. The mean terminal half-life of PRO051 in the circulation was 29 days. PRO051 induced detectable, specific exon-51 skipping at doses of 2.0 mg or more per kilogram. New dystrophin expression was observed between approximately 60% and 100% of muscle fibers in 10 of the 12 patients, as measured on post-treatment biopsy, which increased in a dose-dependent manner to up to 15.6% of the expression in healthy muscle. After the 12-week extension phase, there was a mean (±SD) improvement of 35.2±28.7 m (from the baseline of 384±121 m) on the 6-minute walk test. CONCLUSIONS: Systemically administered PRO051 showed dose-dependent molecular efficacy in patients with Duchenne's muscular dystrophy, with a modest improvement in the 6-minute walk test after 12 weeks of extended treatment. (Funded by Prosensa Therapeutics; Netherlands National Trial Register number, NTR1241.).

Relapse prevention with gepirone ER in outpatients with major depression.

To evaluate long-term efficacy and tolerability of the serotonin 5-HT1A receptor agonist, gepirone extended release (ER), a multicenter, randomized, placebo-controlled relapse prevention study was performed in patients with recurrent major depression (DSM-IV criteria). Patients 18 to 70 years, with a primary diagnosis of recurrent major depression (DSM-IV; 296.3) and a screening and baseline HAMD-17 total score >/=20 were eligible. After a 3- to 14-day (dependent on pretrial medication) single-blind placebo washout period, eligible patients entered an 8- or 12-week (depending on time to remission) open-label gepirone ER treatment period. They initially received a dose of 20 mg/d gepirone ER and were titrated to a dose of 40 to 80 mg/d. Patients who achieved remission (HAMD-17 total score /=16 or discontinuation for lack of efficacy. A total of 420 patients were treated in the open-label phase. Of these, 303 (72.1%) completed the open-label phase and 250 (59.5%) fulfilled the criteria for remission and were randomized into the double-blind continuation phase (gepirone ER: n = 126; placebo: n = 124). The mean (+/-SD) final titrated dose of gepirone ER was 61.9 (+/-17.0) mg/d in the double-blind continuation phase. The relapse rate in the gepirone ER group was statistically significantly lower than that in the placebo group, 23.0% versus 34.7%, respectively (P = 0.024). During the open-label phase, adverse events that occurred in more than 5% of patients were nausea (15.7%), dizziness (13.1%), headache (12.9%), insomnia (6.2%), and vertigo (6.0%). During the continuation phase, the incidence of newly or re-emerging adverse events was similar with gepirone ER (43.7%) and placebo (42.7%). Adverse events different from those occurring during the open-label phase were not apparent. All adverse events occurred in less than 5% of patients with the exception of flu syndrome and headache. In conclusion, gepirone ER at a dose range of 40 to 80 mg/d is effective for relapse prevention in patients with recurrent major depression. It is well tolerated during long-term treatment for up to approximately one year.

A review of the efficacy and tolerability of immediate-release and extended-release formulations of gepirone.

BACKGROUND: Gepirone, a 5-HT(1A) receptor agonist, has been assessed for use in the treatment of anxiety and depressive disorders. Azapirones, including gepirone, act to maintain neurotransmission at 5-HT(1A) receptors. OBJECTIVE: The aim of this article was to review the pharmacology and clinical data for gepirone extended-release (ER) and immediate-release (IR) formulations for the treatment of major depressive disorder (MDD). METHODS: Articles were identified by searching MEDLINE (1966 to present) using the search term gepirone. The reference list retrieved was reviewed for relevant clinical articles. RESULTS: Initial placebo-controlled clinical trials demonstrated that gepirone IR improved symptoms of depression; however, the short half-life of gepirone necessitated frequent administration, and high peak plasma concentrations at higher doses were associated with an increased incidence of adverse events. An ER formulation of gepirone reduced peak-to-trough fluctuations in plasma concentration while maintaining total drug exposure similar to that seen with the IR formulation; the evidence further suggested that lower peak plasma concentrations resulted in fewer adverse events. In clinical trials, both formulations significantly improved symptoms of depression. However, by permitting the use of higher doses of gepirone, the ER formulation had better efficacy and was less likely to produce adverse events (eg, lightheadedness, nausea, dizziness). CONCLUSION: Several clinical trials have suggested that gepirone ER formulations have significant antidepressant effects and better tolerability than gepirone IR formulations when used to treat MDD.