Mino-Lok Trial Math

Can a delayed interim readout be a good thing? Yes it can.

Here is why:

The Phase 3 trial protocol dictates 144 patients need to be enrolled. Also, Myron H. said the trial is well over 80% enrolled [source: frugalnorwegian.com/ctxr/#videos Timestamp 12:02] . Therefore:
144 x 80% = 115.2 patients have been enrolled so far  (rounding up to 116 patients since Myron said “well over 80%”)
92 catheter failures (must occur within 6 weeks of treatment) are needed to end the trial – 12/16/20 10Q page 8, and
Interim analysis is conducted at 65% of the total required failures, therefore:
92 x 65% = 59.8  (~60 catheter failures needed to conduct interim analysis)
The trial has been ongoing for several years. No doubt covid caused a significant enrollment delay, but the fact that 60 catheter failures haven’t happened with 115 patients enrolled is suggestive of positive ML efficacy.
Next we need to determine the Patients per Failure ratio, for this trial.
144 pts / 92 failures = 1.565 pts/failure
Now we calculate how many catheter failures should have occurred at the current 80% enrollment (116 patients enrolled), therefore:
116 / 1.565 = 74.1  ~74 failures
Remember that the 65% interim analysis would be triggered at 60 failures.

Conclusion: Patents are not having catheter failures as expected. Something (most likely Mino-Lok) is responsible for the delay.

It is important to remember that there is a time to failure for treated catheters. We have this from the published Phase 2 Trial (Pg 3428): “In addition, patients receiving MLT were able to retain their CVC for a median duration of 74 days (range, 4 to 240 days) after onset of bacteremia.” Also recall that the patients in the SOC group had their catheter removed sooner than the ML group.
Granted, patients that were just randomized into the trial would most likely not have enough time for a catheter failure to occur.  But the ‘less than 60 events’ status suggests something is preventing the catheters from failing as quickly as expected.
It is also important to note that patients receiving Mino-Lok can still have a catheter failure. After all, the catheter can still get infected again. Mino-Lok can only be administered once (waiting for IR verification). The value proposition of Mino-Lok is that it allows the patient to retain their original catheter much longer than SOC antibiotics. Hopefully it is long enough so they can finish their treatment.