It turns out that this treatment achieved a 2 year CR rate of 35%.
I believe TLD1433 will demonstrate. a considerably better durable CR when we have more data.
The N-803 + BCG CR rate of 71% at any time was achieved by retreating patients who normally would have been removed from the trial. By doing this they added another 16% to the CR rate. Without the retreatment their CR at any time would have been 55%.
You can listen to the interview with Dr. Karim Chamie at:
How Bladder Cancer Immunostimulant N-803 May Shake Things Up For the transcript you need to do a free registration with Medscape. Here are some interesting quotes from it:
"Probably the most important thing that I've learned from this study is that the data look really promising. We had a 71% complete response, and the median durability is about 2 years. You say, "Okay, 2 years later, 35% of the patients are still disease-free, but that means that 65% of the patients either failed initially or failed ultimately." The lesson that we've learned from this is that only about 15% of patients went on to get a cystectomy. I think what we're learning is that maybe these patients' cancers are not as aggressive as we originally thought. The classic teaching during residency and fellowship is that in someone who has BCG-unresponsive bladder cancer — at least based on Harry Herr's study data — you've got to do that cystectomy because their outcomes are significantly better. What we're seeing is that at least in the KEYNOTE-057 study and in this study, most patients didn't have a cystectomy, and they're still alive and doing well. We're becoming a lot more comfortable in our own skin managing patients who failed some of these advanced options. So, I think that's the biggest lesson I've learned from this study."........................ ...................."This is a single-arm study, but we did deviate in the sense that in most studies if a patient had a recurrence of bladder cancer, despite an induction course of a study drug, they were deemed ineligible to receive any additional drug. They basically were eliminated from the trial or excluded from pursuing additional treatment in the study. What we felt was that we were truly looking at patients with BCG-unresponsive disease, and these were patients who absolutely refused a cystectomy. So, we thought, "What if we actually allow patients who maybe had a partial response and see if we can keep them on the study and reinduce them?" Or if they've got low-grade disease, just keep them on the study and continue treatment as though they didn't have a recurrence. There were some modifications in patients who had carcinoma in situ (CIS). Maybe the CIS got a little smaller visibly, even though that's an artificial definition that we were allowed to pursue in the study.
What we found was that most of the complete responses occurred after the induction course. About 55% of patients who received an induction course had a complete response. But that meant that 45% of the people didn't, so they failed the study. What we did was give some of those patients a second shot of an induction course. We found we were able to get an additional 16% of patients to have a complete response. That's how we came up with 71%. We were able to get 55% plus 16%, and that got us to 71% of patients as complete responders."
Dr. Chamie also talked about the QUILT 2.005 study for BCG-naive patients which involves using N-803+BCG as a first line treatment and comparing with the use of BCG by itself. This trial has been put on hold because of the shortage of BCG.