Mast cell inhibition therapy found efficacious in chronic pelvic pain syndrome

In this video, Praveen Thumbikat, DVM, PhD, discusses findings from the study, “Efficacy of targeted mast cell inhibition therapy in chronic prostatitis/chronic pelvic pain syndrome,” which was presented at the 2023 American Urological Association Annual Meeting in Chicago, Illinois. Thumbikat is a professor of urology at Northwestern University in Chicago.

Video Transcript:

In terms of the results, first thing is the tryptase values. The tryptase values, about 80% of the patients who underwent treatment showed a very strong reduction in tryptase levels, clearly giving us a biological correlate that this mitigation really works in the way it is intended to do. The average reduction was about 63% reduction in these patients. Then we move down to the question of symptoms. In symptoms, using the total symptom index, the NIH CPSI, we found a very significant reduction in NIH-CPSI in this patient population. Importantly, we found that the reduction was both in the pain, urinary, and quality of life subdomains, which I think was unexpected, but was quite nice that we got it in all 3 of them. We looked at the US symptom index, and same thing, in the US symptom index, we found there was a reduction.

I did want to make 1 point, for the NIH-CPSI, this is a pilot trial, so we got about a 5.2 point reduction in all patients, but about 9 out of the 15 patients showed a reduction of 6 points or greater, which is often considered clinically significant. It's still not perfect, but because it's a small trial that's all we could do at this point. In the AUA symptom index, we again found a nice reduction. There, an interesting point was the patients who had the greatest voiding symptoms, those who are classified under standard BPH criteria as having moderate to severe symptoms, they showed the greatest response. In that subset, we found a 3 point or greater reduction in the AUA symptom score, suggesting that it is most likely clinically significant for them.

Then, we also looked at immune parameters in these patients. We collected cells from the BB3 urine of these patients and looked at NanoString analysis to look at immune cells before and after. What you see is the mast cell inhibitors change the immune milieu within the prostate. You find reduction in different types of T-cell subsets, you find a much more anti-inflammatory fighter phenotype with of the immune cells within the prostate.

In conclusion, it's a pilot study. The caveats, obviously being that it's not placebo controlled, and it was a small study with only a limited number of patients. That said, we were using a biological surrogate here, in this case, mast cell tryptase, so I think that was powerful. What we can say is that using mast cell tryptase is an effective way to discriminate patients with mast cell dysfunction from this heterogeneous CPPS group. Number 2, in that subset, treatment with mast cell tryptase has the likelihood of clinical benefit in that subgroup. One point I forgot to mention was when you look at the kinetics of treatment, both using the CPSI and the AUA symptom index, you find a nice stepwise increase in benefit the more number of weeks that they have been on treatment. Again, we only use 3 weeks, which is a drop in the ocean floor, compared with what these patients are going through.

This transcription has been edited for clarity.