Toviaz extended-release tablets win FDA approval for treatment of overactive bladder
The Food and Drug Administration has recently approved Toviaz (fesoterodine fumarate, Pfizer) extended-release (ER) tablets for the treatment of overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and frequency.
Overactive bladder is characterized by urgency, with or without urge incontinence, usually with frequency and nocturia. The U.S. Department of Health and Human Services has reported that approximately 13 million people in the United States suffer from OAB and other forms of incontinence.
The approval of Toviaz ER tablets was based on two phase 3, double-blind, placebo-controlled, 12-week studies in 1,964 patients with OAB who were randomized to Toviaz 4 mg (n=554), Toviaz 8 mg (n=566), or placebo (n=554). In one of the studies, 290 patients were randomized to an active control arm (an oral antimuscarinic agent). Patients had to have symptoms of OAB for ≥ 6 months, ≥ eight micturations per day, and ≥ six urinary urgency episodes or three urge incontinence episodes per three-day diary period. The primary endpoints were the mean change in the number of urge urinary incontinence episodes per 24 hours and the mean change in the number of micturations per 24 hours.
In both studies, at week 12, patients who received Toviaz 4 mg or 8 mg/day had a significant decrease in the number of urge incontinence episodes per 24 hours from baseline compared to placebo, with a reduction seen as early as two weeks after the initiation of therapy. At week 12, there was also a significant decrease in the number of micturations per 24 hours compared to placebo. A greater reduction in both endpoints was observed with the Toviaz 8 mg/day dose.
The safety of Toviaz was evaluated in phase two and three controlled studies in a total of 2,859 patients, of whom 2,288 were treated with fesoterodine. The incidences of serious adverse events in patients receiving placebo, Toviaz 4 mg, and Toviaz 8 mg were 1.9 percent, 3.5 percent, and 2.9 percent, respectively.
Dry mouth was the most commonly reported adverse event in patients who were treated with Toviaz. The incidence of dry mouth was higher in the Toviaz 8 mg group (35 percent) and in the Toviaz 4 mg group (19 percent) as compared to placebo (7 percent). Dry mouth led to discontinuation in less than 1 percent of patients. Constipation was the second most-common adverse event reported, seen in 6 percent, 4 percent, and 2 percent of patients taking Toviaz 8 mg, 4 mg, and placebo, respectively. The product labeling states that Toviaz is associated with an increase in heart rate that correlates with increasing dose.
Veronica Fernandez is a pharmacist based in New Jersey.