I have found a prequal paper relating on this matter. I think one of the cause is that the discussion between FDA and urologists to define BCG unresponsive started before the BCG shortage became serious. The discussion started before 2015 and the announcement of Sanofi's decision to withdraw from BCG business which led to semi permanent BCG shortage was announced in 2016. They could not think about its implication then.
Anyway, the prequal paper states "Adequate BCG treatment" which is defined as 5-6 weeks induction course and 2-3 weeks maintenance course. Incidentally, I have read somewhere that why 2 or 3 years of maintenance treatment is not required to be classified as adequate BGC treatment is their recognition of other BCG treatment protocol such as 6 weeks + 6 weeks (maintenance) are being used.
1. variation of amount of dosage to mitigate the impact of BCG shortage, recommendation by AUA for the dose reduction to 1/2,1/3 in case of the shortage.
2. variation of BCG strain : SWOG - a a National Cancer Institute supported organization that conducts clinical trials in adult cancers started clinical trial to compare Tokyo-172 strain BCG manufactured by Japan BCG Lab and MERCK Tice strain BCG. There are about 1,000 participants in the clinical trial.
3. variation in timing of BCG treatment : use of different protocols, delayed treatment by shortage, side effects created wide range in BCG timing, so the paper recommends to limit enrollment to those who had adequate BCG over 6-9 months.
4. patients who had received the treatment for a BCG unresponsive were not eligible for different BCG unresponsive treatment. The paper suggests the inclusion of those patients to a different treatment for BCG unresponsive if sufficient time elapsed from the first treatment.
I think understanding of the inclusion criteria for a clinical trial is important as it will likely be applied to the inclusion criteria for the eligibility to the drug and the insurance coverage when the drug is approved and become available for for patients in general.
The paper was authored by Dr. Roger Li of Moffitt and coauthored by Dr. Seth Lerner of Baylor and Dr. Ashish Kamat of MD Andersons.
best