Replies to post #241020 on Avid Bioservices Inc (CDMO)

[tradero]

LOOKINs Projections.Part III:Results and Conclusions

(continues from posts #241019 and #241020)
As I said earlier we will base all calculations on the enrollment numbers explained in part I, which seem pretty reliable if enrollment completion happens this December.
These enrollment number have been split and distributed in different enrollment groups per month as shown on the table below. To make things clear it will only show from Jan. 2015 onwards.


We saw in Part II that a MOS of 7 months for Placebo and of 11 months for Bavi gave some results that said that 1st lookin should have already taken place. So this means that MOS should be higher than that. This is VERY good news for PPHM because MOS for Bavi should be higher than 11 months

So let’s see which MOS to test:
- For Placebo we can try a 9 months MOS (top of the range for placebo since historically it seems that it has NEVER been more than that). Using this 9 months number means playing conservative for the Bavi MOS, because we would be in the low range expectations for Bavi. An actual lower MOS for Placebo would give a higher MOS for Bavi.
- For Bavi we will start with a MOS of 15 months, then for 17 and finally for 19 months.

In all cases we will use “spreadout” distribution for MOS, since as we saw in Part II this yields to shorter dates for 1st lookin… and thus we would be advancing the date for the 1st lookin compared to if we would use a more “concentrated” approach.

So let’s see what happens with these cases


And these are the results:

The overall chart:

Case1 corresponds to BAVI 15 MOS
Case2 corresponds to BAVI 17 MOS
Case3 corresponds to BAVI 19 MOS

Let’s zoom in the chart:



So the results say that, with a Placebo of 9 months MOS… 1st Lookin might happen in:
? BAVI with 15 MOS around 1st half of January
? BAVI with 17 MOS around 1st half of February
? BAVI with 19 MOS around 2nd half of February

(Don’t forget that in Part II we saw that because of the lack of 100% accuracy in the MOS distribution tables there might be an error margin of 1 week if the real distribution is “spreadout” and of 3 weeks if it is “concentrated”.)

It is clear that the later the 1st Lookin happens the higher the MOS is… and the better for BAVI

This exercise has followed the rule that whatever takes place within a month has been considered to happen at the end of the month, i.e. “delaying” the action. In the same way we have considered that 1st Looki takes place after 200 events, when as some people indicated on the board… because of patient censoring this number should be somewhat lower. Again our approach is delaying the result than the actual one and all these “calculation” delays are favorable to a higher Bavi MOS.
Also we shouldn’t forget that there might be a time gap from actually reaching the Lookin and PPHM knowing this has happened and therefore PRing it.

Notes.
Of course, this is guesswork based on reasonable assumptions and with best of intentions. It is very likely that it may not get close to what really is going on, but nonetheless it can give us some orientation.

In regard to the MOS simulation tables, I have designed them using “my” common sense which may not be in close agreement with reality. So I would appreciate if somebody in the Board could share some insight on this respect in order to arrive to a more accurate result. Anyway, back in Part II we saw the range of this error margin.

I welcome comments, suggestions and possible corrections of the assumptions I have taken.
I am pretty confident in the Enrollment model IF enrollment ends in late December
If someone has some suggestion regarding the MOS distribution, please let me know them and now that the Excel tool is working… results come automatically

The excel file (Visual Basic included) is also available to whoever wants it.

[pphmtoolong]

trader, I appreciate the hard work going into this study. I do have a question regarding your eventing tables. If the median period for eventing is 11 months, shouldn't the number of survivors after 11 months equal 50% of the patients? Your tables show fewer than half of the patients in the over the median break point.

Thanks, Paul

[pphmtoolong]

tradero, let me try again to explain my question.

In your eventing Case 1 Table under the Placebo column, the total at bottom is 50% for those patients getting the placebo. So far, so good.

Now if we add the percentage of events in that column for 3, 5 and 7 months we get 5 + 11 + 18, or 34%. So, for the first 7 months, we get 34% of the 50% of the Placebo patients eventing. That leaves only 16% of the 50% Placebo patients surviving over 7 months.

My expectation was that of the 50% of the trial patients who are on the placebo, 25% would survive less than 7 months and 25% would survive more than 7 months.

Perhaps, your table is affected by the enrollment rate's increase over time?

TIA, Paul