MILAN—Intravesical alkalized lidocaine (PSD597) may be an effective short-term and possibly long-term treatment for patients with interstitial cystitis/painful bladder syndrome (IC/PBS), data suggest.
At the European Association of Urology 23rd Congress here, J. Curtis Nickel, MD, professor of urology at Queen’s University and Kingston General Hospital in Kingston, Canada, presented results in 102 adults who were randomized to receive daily instillation of intravesical alkalized lidocaine or placebo for five days and then followed for 10 days. Patients were then offered open-label treatment for an additional five days and were followed for another 10 days.
Dr. Nickel noted that lidocaine by itself is not absorbed and does not confer anesthesia because of the acidic environment. By injecting a single dose of lidocaine followed by bicarbonate, the lidocaine is absorbed and provides short-term pain relief. “We hypothesized that daily instillations would provide prolonged symptom relief even after the immediate short-term effects of the lidocaine had worn off,” Dr. Nickel said.
“Such a therapy would not only offer immediate relief of symptoms (for acute flares), but if successful would suggest that long term downregulation of the bladder sensory nerves is possible.”
The study found that roughly three times as many patients treated with intravesical alkalized lidocaine reported their overall bladder symptoms as moderately or markedly improved on the Global Response Assessment Scale on day 8 (three days after last instillation) compared with placebo (30.0% versus 9.6% for the two groups, respectively, a significant difference between groups). The patient-rated Global Response Assessment, the study’s primary end point, is a widely validated tool for quantifying treatment response and measures changes in pain, urinary frequency, and urgency.
Ten days later (with no further therapy), twice as many patients still reported clinically significant responses (24.0% vs 11.5% for placebo group) but the difference was not statistically significant at this time point. When response was analyzed across all Global Response Assessment categories, the difference between treatment with intravesical alkalized lidocaine and placebo at day 15 was significant (65.9% vs. 41.7%).
Overall, 86% of patients who received lidocaine elected to receive a second course of treatment, “thereby offering direct evidence of treatment acceptability and the lack of alternative treatment options,” Dr. Nickel noted.
He pointed out that additional improvements observed after the second dosing demonstrate not only that the benefits of intravesical alkalized lidocaine held up for a substantial amount of time after treatment, but also that clinical benefits can be enhanced with increased dosing.
Finally, the Canadian investigator said treatment was safe and well tolerated when instilled into the bladder.
Notably, the investigators observed none of the systemic adverse effects commonly seen with oral drugs. The total number of adverse events and severe adverse events were similar in number and pattern between the two treatment groups except for bladder pain which occurred in 14% of patients who received intravesical alkalized lidocaine and 45.8% of placebo patients.
The study was carried out at 19 centers in Canada and the United States.