res, it looks like you called it right: They didn't do the math right.
taurx compared those on LMTX who did not feel it necessary to take Alzheimer's drugs because they were non-progressors or did not have Alzheimer's in the first place
to those not on LMTX who did feel it necessary to take Alzheimer's drugs because they were progressors (possibly rapid progressors).
Under such a study design any "treatment" would be expected to do better than placebo.
With such a scenario, 1 in a million p values and a positive primary endpoint readout on the monotherapy subgroup on the second phase 3 trial notwithstanding, the trial cannot claim success.
I have been fooled a few times on small subgroup analysis (for example, the bapineuzumab phase 2).
This is the first time that I have been fooled on a positive primary analysis. (taurx confirmed that the second phase 3 will use the LMTX monotherapy as a primary endpoint.
They have also said that this LMTX monotherapy subgroup also saw benefit relative to the placebo group treated with standard of care.)
This could be an exercise in pathological science.
taurx might proclaim success in the primary analysis in a phase 3 trial, without it actually being a success.
That has brought us nearly up to date.
The new twist is that taurx also said that they intend to combine the monotherapy and untreated placebos in the two phase 3s to see if there were a treatment effect.
Such an analysis would have approximately 100 patients on monotherapy LMTX and perhaps 80 on untreated placebo.
I am very unsure how one could rebut a positive response to such an analysis, if it were to occur.
The two arms- LMTX monotherapy and placebo non-treated- would be blinded.
There is an open label extension trial that has been accruing for 2 years now and is expected to enroll 1000 patients.
All those on the open label are being treated with LMTX.
If they simply ask the patients not to take standard of care while on LMTX, then it would become rapidly apparent whether LMTX were effective or not.
Of course asking these patients to do so would not be ethical if LMTX were known to be ineffective.
One problem, though, with the extension trial is that they do not appear to have continued with the mental status tests.
If they are serious about determining whether LMTX is effective, then they need to restart the cognitive testing (ADAS-Cog, ADCS-ADL ...).
Given how large the treatment effect has claimed to be, we should know fairly soon whether LMTX is effective or not.
taurx could also start a smallish and shortish follow-on study that could clarify the results of the phase 3 trials.
Edited by mag1, 30 July 2016 - 02:30 PM.