RE:Canaccord Warming Back Up to THTX? Based on RECIST the rule is for you to call something a CONFIRMED response you need two scans to show a response and they need to be done at least 4 weeks apart (in our case probably 6 weeks I.e two cycles). An UNCONFIRMED response would be after just the first scan. Response means greater than 30% tumour shrinkage.
My idea on scans (I don't know where I get this) is that they scan at the end of cycle 2 and 4 and 6 etc. So the best possible scenario is an unconfirmed response at the end of cycle 2 (6 weeks) and a confirmed response at cycle 4 (12 weeks). Of course if the unconfirmed response doesn't come until the 2nd of 3 rd scan then you keep adding 6 weeks to the process.
In terms of the numbers of patients I think one is enough. The 2 patient scenario is not for proof of concept. It's for the 1b trial outcome and the way I understand it it is the trigger for the go/no go decision on each individual cancer. It's a crude measure from a small sample size of whether you think you have a chance of hitting the ORR goal in the registrational trial.
So the best case scenario for a solid proof of efficacy signal would be one patient hitting a confirmed partial response and the minimum for that based on my assumptions is 12 weeks after their first injection of drug. But of course this is absolute best case scenario, it likely won't happen this way.
When it comes to 1b I expect there will be an efficacy, safety and commercial component to the decision making process. From the efficacy perspective it seems to be two responders from 15 as the target. Like you say that could happen super quickly if you believe in miracles but even then I think they will probably need to fatten the safety database by getting a minimum number of doses inside patients. From a commercial perspective you'll probably want the best data set possible to support financing and to pick the most likely path to success. It does seem like assuming everything goes super well (it probably won't) then there is a potential to derisk on the efficacy side quite early into the 1b and that could trigger a press release. This is definitely setting expectations too high though.
SPCEO1 wrote: As we are painfully aware, the Canaccord analyst has had THTX in his penalty box for a long time. But he put out a prompt report this morning (recall it took him almost two weeks, which is incredible, to put out a report on THTX's last quarterly earnigns call) noting the start of the phase 1b which included a commitment to factor cancer into his model once proof of concept is seen.
When might that be seen? It could actually be earlier than we have been thinking in the phase 1b. If everything went perfectly optimally (which basically never happens) it would be possible we saw results from the second scans confirming preliminary efficacy by the end of June. How, you ask? Well, the pahse 1b got started earlier than we expected and some/all of the first three 300 mg dose patients may have rolled right into the phase 1b. If so, the phase 1b effectively started when those first three patients got their first dose, which I am guessing occurred in late March since in mid April they had complete their first cycle of treatment (based on what was said on t he mid-April conference call).
Now, I don't know the specific rules areound declaring preliminary signs of efficacy. First I have to assume you need at least two instances of tumor regression afer twelve weeks and two scans. This must have to be in the same cancer type as well. So, if two of those first three patients has the same cancer type and both showed tumor regression, then THTX can declare preliminary signs of efficacy, I think (any help with the rules around declaring preliminary signs of effcicacy from those in the know would be appreciated). The chances of all the conditions being met are tiny but it is fun to think about.
My contact who mingled with the THTX honchos before the annual meeting yesterday heard there was to be a discussion at the board meeting following the AGM yesterday discussing some recent input from the investigators on the trial. Could that have been the results of the first scan? Were those reults positive or negative? We can only speculate but thereis a very small chance THTX is already half way there to declaring preliminary efficacy.
Then we can see how much credit Canaccord and the other analysts will give THTX for their cancer program. Whatever they give will be heavily discounted due to how early we are still in the testing program for TH-1902. But at least it will be something!
If you really want to keep dreaming, then hope that two of those first three 300mg patients had ovarian cancer and both show tumor regression. If that tumor regression is as good as seen with normal docetaxel patients where docetaxel is the first line of therapy for ovarian cancer, then things could speed up very quickly for TH-1902. A phase 2 study would be started pronto and, if TH-1902 was to reveal that it is better and safer than normal docetaxel treatments, it might get anaccelerated approval sometime in 2023 and it should then quickly become the first line treatment for ovarian cancer.
OK, now it is time to come backdown to earth as the chances of any of that happening have to be 1 in 1000 or less. Everything would have to go right and that never happens, especially when you are dealing with very, very ill patients who have been through all sorts of cancer therapy already.
Even so, we may get a preliminary efficacy signal sooner than we thought. but it likely will not be on the optimal type of cancer from our prespective, which I believe would be ovarian.