RE:RE:RE:RE:66% the number to beat...Hi CancerSlayer,
I just saw your post. I'm stilll hoping Theralase gets that 66% CR in 25 patients at one year. If not maybe the FDA will lower the bar.
66% of 25 patients (17 patients) may seem like a pretty small number of patients to base approval on but Keytruda only achieved this number of patients with their 19% at 12 months.
I agree the FDA "
established a de facto "new" bar after their approval of Keytruda, which demonstrated a 41% CR at any time & a modest 19% CR at 12 months (post initial CR)" These percentages were based on the treatment of all of the
102 patients in Cohort A , not just the
first 25 patients to hit the 12 month mark..
Merck's 19% at 12 months after all patients had been treated and scored
amounts to only 17 patients! If the Theralase trial achieves a
CR for 17 patients after only 25 have been treated they will have already achieved
similar total 12 month CR results to Keytruda with 75 patients still to go!
https://www.fda.gov/media/133542/download CancerSlayer wrote: Eoganacht wrote: I agree that "the threshold for approval is likely significantly less" than 66% if we are talking about the percentage of the 100-125 patients in the trial who end up having a CR at 450 days. The 66% refers to the percentage of 20-25 patients who are CR one year after their first cystoscopy which the FDA communicated was required in order for them to grant us early approval. This condition for early approval was first revealed to us by Dr. Jewett in his appearance on the BTV show in August 2018. In the show he said this benchmark for early approval came out of a conversation Theralase had with the FDA. This claim was reiterated several times in news releases by Theralase. Maybe the FDA will decide to lower the bar if the results for the first 25 are something less than 66% at one year, but even if they don't, in my opinion, TLD1433 pdt for NMIBC is headed for approved.
CancerSlayer wrote: Based on the data thus far from optimized patients, it certainly looks like a threshold we can beat.
In view of the natural/lethal course of BCG-unresponsive CIS & the negligible efficacy/limited number of available "non-invasive" treatment options, the FDA gave appropriate guidance imo. It states it does not recommend or require any pre-specified response rate. Such guidance certainly works in our favor, & even though a 66% CR rate appears attainable (especially post "two" optimized treatments), the threshold for approval is likely significantly less imo. Keytruda & Valrubicin got approved based on significantly lower complete/durable response rates that left a lot of room for improvement. We've already exceeded Keytruda's CR mark of 41% based on 33 patients, of which 45% (15 of 33) didn't even get the two fully optimized treatments as currently recommended.
I don't see how this ACT doesn't maintain at least 41+% CR mark moving forward. As I stated in an earlier post, I really don't see how this doesn't get approved. JMO.
Appreciate your input...per the 2Q 2020 newsletter:
"It was further discussed that Theralase would potentially be eligible for Breakthrough Therapy Designation (“BTD”) and / or Accelerated Approval (“AA”), if Theralase could demonstrate clinically significant results (high safety profile and high efficacy response), similar to the safety and efficacy results observed in the Phase Ib NMIBC clinical study (high safety profile and significant CR) at an interim analysis of approximately 20 to 25 patients enrolled and successfully treated."
I guess I'd be considered a relatively new investor (came in after 2018). However, the above statement can be a little confusing to your average investor when BTD & AA are used in the same sentence & their eligibility is based on the "same patient number" requirement (20-25 patients), albeit at "different interim analysis timeframes"...CR at any point in time (generally 90 days) for a BTD, & CR data at 450 days for an AA. Certainly, a BTD is historically based primarily on early efficacy signals (I.e. 90 day CR data only) with no need for significant/any durability data.
Imo, the FDA has now established a de facto "new" bar after their approval of Keytruda, which demonstrated a 41% CR at any time & a modest 19% CR at 12 months (post initial CR). So, there's now an added option, but "satisfactory" non-invasive treatment options are essentially still absent. Assuming TLT achieves a significantly higher CR% in 20-25 fully optimized patients & continues to show a comparable/better safety profile, I feel that 2018 threshold of 66% may now have some flexibility. With the recent reignition the Cancer Moonshot goals as announced by Biden last month, the FDA's stance on early approvals imo has likely changed...for the better.