Cel Sci Corporation (CVM)

[Fosco1]

you can have 90 at Y1, what counts is :
1) the initial slope
2) the flatnessness afterwards. All OAS curves shown so far on H&NC have shown flatnessness

I remade(quickly) your computation with your V2 (55%) data and a log curve (78% at Y1) that mimics UK data. I found really a great gap with your initial analysis

y = aln(t) + b
a = -14.32
b= 78

A good guide on survival curves here :

https://www.cancerguide.org/scurve_basic.html

Excerpt :
"Many curves show a decreasing risk of death over time (If the risk decreases to zero you get a plateau!). Some curves appear to have a roughly constant risk of death over time. A constant risk of death leads to an curve which represents exponential decay like the decay of a radioactive element. In a perfect mathematical world, an exponential decay curve doesn’t actually reach zero, but with any limited number of people to start out with, such a curve will eventually reach zero. It can be very difficult to detect decreasing risk by eye – but the evidence is that even for advanced cancers with a poor prognosis there is a good chance the survival curve is decreasing risk"