Congrats and thank you for posting your treatment for BCG unresponsive non muscle invasive bladder cancer. I know that Keytruda itself had already been approved by FDA for BCG unresponsive non muscle invasive bladder cancer.
It looks like it is still in the Phase III clinical trial stage. A preliminary analysis of a Phase I study showed better result than Keytruda alone for BCG unresponsive non muscle invasive bladder cancer according to the report by Dr. Ashish Kamat of MD Andersons. (refer the link below).
Below is the link to the Phase III clinical trial
clinicaltrials.gov/ct2/show/NCT03711032
Below is the link to the paper by Dr. Ashish Kamat on the rational for the treatment of BCG and Keytruda (Pembrolizumab) combined.
www.futuremedicine.com/doi/10.2217/fon-2019-0817
A preliminary analysis of a Phase I study of intravesical BCG combined with pembrolizumab in patients with high-grade NMIBC after treatment failure with at least two courses on intravesical therapy (one contains BCG) showed that the combination therapy had an overall response rate of 67% and was well tolerated with acceptable safety
best