Mycobacterial cell wall therapy may be an alternative to BCG in the treatment of carcinoma in situ (CIS) of the bladder, Dr. Alvaro Morales, of Queen's University, Kingston, Ontario, reported at the AUA meeting.
The cell walls of Mycobacterium phlei (an organism similar to M bovis) were instilled into the bladder of 68 patients at a dose of 4 mg once a week for six weeks, then monthly for one year.
At 12-week follow-up, 40 of 64 evaluable patients had responded to treatment: 33 with complete response and 7 with partial response. All 9 patients remaining in the study at 78-week follow-up were complete responders, Dr. Morales said. Of those who had failed previous BCG therapy, 48% responded to cell wall treatment.
Adverse events were "much less intense than with BCG, though of a similar kind," he said, listing fever, chills, and malaise of "very short duration." No sepsis occurred.
"At this low dose, mycobacterial cell wall was less effective than BCG, but dose escalation studies are needed," Dr. Morales said, adding that mycobacterial cell wall could potentially be used as a rescue agent for BCG failures.