MCC ConclusionsTuesday, May 22, 2012 1:00 PM-3:00 PM Bladder Cancer: Superficial II Moderated Poster Endo Pharmaceuticals/Bioniche Life Sciences 1783: SAFETY OF INTRAVESICAL MYCOBACTERIAL CELL WALL-DNA COMPLEX GIVEN IMMEDIATELY POSTSURGERY IN PATIENTS WITH NON-MUSCLE-INVASIVE BLADDER CANCER Alvaro Morales David Jablonski Christine Lihou Zhihui Lang Zvi Cohen Kingston, Canada Introduction and Objectives Intravesical chemotherapy is recognized as effective immediately after transurethral resection of bladder tumor (TURBT)/biopsy, whereas bacillus Calmette-Guerin (BCG) is contraindicated for ≤2 weeks postsurgery to allow for urothelial healing, due to risk of serious complications. Mycobacterial cell wall-DNA complex (MCC), derived from the nonpathogenic Mycobacterium phlei, exhibits a dual mechanism of action, with both direct chemotherapeutic effects and immunostimulatory effects. MCC is a sterile suspension which has been investigated in multiple clinical trials and shown to reduce non-muscle-invasive bladder cancer (NMIBC) recurrences after BCG failure. Phase III clinical trial data were analyzed to determine whether MCC could be safely instilled immediately after NMIBC-related surgery. Methods Retrospective analysis identified patients who received their first MCC dose immediately postsurgery in a clinical trial in patients with BCG-refractory high-grade NMIBC. Patients received 6 weekly MCC instillations, followed by 3 once-weekly instillations at 3, 6, 12, 18, and 24 months. At their discretion, and considering their previous experience with MCC treatment, some investigators instilled MCC ≤1 day postsurgery. Results 14% (18/129) of patients received MCC within 24 hours of surgery (32 instillations total); 12% (16/129) received MCC on the same day of surgery (28 instillations total). Adverse events (AEs) were experienced by 28% (5/18) of patients following 16% (5/32) of instillations (all in different patients and all when MCC was given on the day of surgery). In 4 of these 5 instillations, AEs consisted of hematuria, urinary frequency, dysuria, and suprapubic cramps. All were mild to moderate in severity and not considered treatment related. One patient experienced rigor, nausea, and headache with moderate severity after 1 instillation (possibly related to MCC). No AEs resulted in treatment discontinuation. 3 of the 5 patients received an instillation on the same day of surgery at another time without experiencing AEs. 39% (7/18) of the patients were disease free at 1 year. Conclusions MCC was well tolerated when instilled intravesically immediately after TURBT/biopsy in this group of patients. Further investigation is needed to determine if MCC, like cytotoxic agents, can be administered in the immediate postoperative setting to prevent reimplantation of circulating tumor cells and potentially impact the rate of recurrence.