For my ultra conservative analysis I used SOC 55% after 3.3yrs, 50% for 4yrs and 45% for 5 yrs. Used 50% for LI for 4/5 yrs. Also scaled 144 non evaluable subjects by -15% in 4/5 yr groups. The reported 3 yr survivability rate is a median, half on each side so I added 3 months. Therefore, my numbers are time shifted form your analysis. August is when my analysis indicates 10% success.
The study s/b reported when >157 subjects have passed in "either" control group. Continuance would only serve to determine degree of success or failure. I would suspect the FDA would consider this.