BCG shortage: Reassessing the clinical viability of Bacillus Calmette-Guerin (BCG) after reconstitution.
534 Background: To address the current worldwide shortage of BCG, the AUA and SUO recommend reducing the dose to 1/3rd vial and enabling 3 patients to be treated in one setting. The manufacturer states that BCG must be used immediately after reconstitution, despite literature in the bacteriological world suggesting that M. Bovis might be viable for longer than a few hours. Herein we sought to study the viability of BCG after re-constitution at time points relevant to clinical practice. Methods: TICE BCG from separate lots was reconstituted per the manufacturer’s guidance and stored at 4 °C without light exposure. At predetermined time points, BCG was inoculated on Selective Middlebrook 7H11 agar in triplicate and incubated at 37°C with 5% CO2. M. smegmatis served as a positive control and un-inoculated media was incubated for 2 weeks as a negative control. CFUs were assessed between 3 and 4 weeks from plating. Acid-fast staining confirmed the presence of BCG. Data was analyzed as the mean of replicated experiments and compared to the reference (Time 0) using Student’s T-tests. Results: No significant difference in CFUs was observed for BCG between 0 and 8 hours after reconstitution (Table). Colony forming units significantly declined starting 24 hours after reconstitution, though the magnitude of this difference was less than 10 fold (which falls within the range of CFUs listed for the vial by manufacturer). Viability remained constant for both lots analyzed. Conclusions: Given the recurrent shortages of BCG, split dosing may become a clinical necessity. This often presents logistic quandaries since the manufacturer recommends each vial must be used within 2 hours. We have shown that the viability of TICE BCG is unaltered at least 8 hours after reconstitution and only begins to decline at 24 hours after reconstitution. This should allow pharmacists and physicians administering BCG more leeway in scheduling patients for split dose therapy. [Table: see text]