Cancer Treatment Today

National Comprehensive Cancer Network (NCCN) Guidelines recommend a second round of BCG therapy only if there was a long disease-free interval after the first treatment. In the absence of a long interval, the Guidelines recommend a change of treatment based on the tumor histology and the previous treatment. NCCN has no specific recommendation in this situation.
There is support for  BCG maintenance for the initial treatment of high grade non-invasive tumor based on the original SWOG trial published by Lamm et al. (2000). What to do at the first recurrence, is far less clear. Studies have been hampered by a lack of good definition of types of recurrence until a consensus was reached in 2014 and published by Jarow et al. (2013). The use of BCG plus alpha interferon at the time of recurrence has been specifically reviewed by Gallagher and co-authors. This review showed that the use of BCG with or without interferon in patients who recurred less than six months after induction BCG intravesical therapy produced no real benefit.
Therefore, the use of BCG plus interferon in a BCG-unresponsive patient does not have support in either guidelines or the current medical literature. It has not been shown to be effective.

NCCN Guidelines: Bladder Cancer. Version 2.2016, BL-2, BL-3, BL-G

Lamm DL, Blumenstein BA, Crissman JD, Montie JE, Gottesman JE, Lowe BA, Sarosdy MF, Bohl RD, Grossman HB, Beck TM, Leimert JT, Crawford ED. Maintenance bacillus Calmette-Guerin immunotherapy for recurrent TA, T1 and carcinoma in situ transitional cell carcinoma of the bladder: a randomized Southwest Oncology Group Study.   J Urol. 2000 Apr;163(4):1124-9

Jarow JP, Lerner SP, Kluetz PG, Liu K, Sridhara R, Bajorin D, Chang S, Dinney CP, Groshen S, Morton RA, O’Donnell M, Quale DZ, Schoenberg M, Seigne J, Vikram B.  Clinical trial design for the development of new therapies for nonmuscle-invasive bladder cancer: report of a Food and Drug Administration and American Urological Association public workshop.
Urology. 2014 Feb;83(2):262-4. Epub 2013 Dec 12

Gallagher BL, Joudi FN, MaymíJL, O’Donnell MA. Impact of previous bacille Calmette-Guérin failure pattern on subsequent response to bacille Calmette-Guérin plus interferon intravesical therapy.   Urology. 2008 Feb;71(2):297-301