NorthWest Biotherapeutics Inc (NWBO)

[meirluc]

4. (18 Distribution of final 31 patients): ALL PATIENTS WERE RANDOMIZED You can't just put a group in one arm or the other. NWBO had nothing to do with which patients ended up in which arm. Because of the large number of sites, the final randomization may not have been exactly 2:1 but may have been off by a few people one way or the other.

The final randomization was 2.34:1, and definitely more off by a few people from the planned 2:1 ratio.

It is also remarkable that the last group of about 108 patients (32.6 of the trial), ended up with at least 42 of the 93 (45%) post 36(+) months survivors, whereas of the preceding 223 patients only at most 51 (22.9%) were post 36 months survivors.

If the randomization pattern was roughly the same throughout the trial, what were the reasons for the later group's superior survival capacity?

During March 2017 when the data for the 2018 JTM article was collected, 62 of the 108 patients ( 57.4%) were still alive and 46 (42.6%) had died.
I am estimating that at that time the median time on trial for the last group of 108, was about 22 months and the mOS of that group, with 54 alive and 54 dead would roughly have occurred at 24 months. This would not be very different than the 23.1 months mOS of the entire trial. Therefore, at that time (2017-2018) that last group of 108 patients did not seem remarkable.

However, something remarkable must have happened thereafter because of those 62 March 2017 survivors belonging to the last group of 108 patients, at least 42 (67.7%) went on to survive at least 36 months.

If the survival capacity of that last group of about 108 was not related to an overrepresentation of Treatment patients, what were the reasons for this group's superior survival record?