Problem is your table only gives a dose response curve from 0 (Placebo) to 120 (max) for the 18 "identical" patients. It is unlikely to be the case.
It gets more complicated as other variables which might influence response get taken into account such as duration and severity of the illness and dose and baseline response to L-dopa. The usual demographic data such as age and sex of the trial patients will also be included.
Then we have the single primary outcome and 7 secondary outcome measures. While the trial goes for 26 weeks, there might well have been multiple evaluations - in the first trial the patients were examined every 4 weeks. So a wealth of data could be generated which will need to be analysed.
The expectation would be that all of the patients (including the placebo ones) will show an initial improvement in the PDQ-39 Quality of Life scores, but this will decline in the placebo patients over the six months while being sustained in the treated patients. The placebo patients will not show any improvement in objective observed motor performance and may require an increase in medication, whereas the treated patients will show a steady improvement in motor performance over the six months and a reducing dose of medication. The improvement in response will possibly be faster and more complete in those patients with less severe disease to begin with, and a slower but still significant response in the more severely affected patients who initially were on more medication to begin with. Age and sex might not be significant factors when severity is taken into account. If data is available after the 26 weeks it will likely show continued, sustained improvements.
Honestly I am not sure how much effect bigger doses will have over six months. Neurones grow relatively slowly and probably LCT had some good reason to start with a dose of 40 based on their animal testing. But given that some of the implanted cells will probably die, more might be better so a reasonable position would be to guess that 80 will be better than 40 but 120 not much of an improvement over 80.
All just educated guess work on my part, but LCT are "eagerly awaiting the results...", so perhaps that indicates some confidence. I'm betting heavily that the result will be positive in all groups except the placebo patients, but there will be considerable variation in response of the treated patients according to the initial disease severity. The result will be clear however.
