EHA 2023 | Phase II study of brentuximab vedotin + CHP in patients with PTCL with less than 10% CD30 expression

So the BV and CHP has been approved in peripheral T-cell lymphomas where CD30 expression is high, and particularly in a subset of peripheral T-cell lymphoma which is called ALCL – anaplastic large cell lymphoma. It’s made a huge difference, met the primary endpoint of PFS and overall survival in the ECHELON-2 study, and that study has now also published a 5-year follow-up data. And what was not seen in that cohort of patients was responses in the non-ALCLs – there were a few patients with non-ALCLs, who were CD30-positive that were enrolled in the study. And just a reminder, the inclusion criteria for the study was to have CD30 expression of 10% of higher, and all ALCLs obviously have 100% expression of CD30, and then you have the non-ALCLs like the PTCL-NOS and the angioimmunoblastic T-cell lymphoma that had CD30 expression about 10%, scored both locally and centrally.

And there was responses seen, the survival benefit is very clear in ALCLs, because the group E-2, the ECHELON-2 was enriched for the ALCL population. In the non-ALCLs, the PTCL-NOS and AITL, you saw some response in PTCL-NOS, in AITL it is very hard to say because of course the numbers are very small. So, while that was a very good study that led to the approval of this combination in CD30-positive ALCLs and non-ALCLs, we wanted to explore the question of whether it also made an impact in those patients with CD30 expression less than 10%, all the way to zero – which means less than 1% expression.

And so the poster that I had yesterday, last evening, was looking at CHP with BV, CHP-BV, in patients with non-ALCL PTCL that had expression of less than 10%, or even zero expression, newly-diagnosed patients, and what the responses are. So, we are presenting our first data cut, it is a single-arm study looking at non-ALCL patients with less than 10% or zero expression of CD30, and there were 55 patients enrolled and 46 patients got at least one dose of treatment. And the CD30 is measured both locally and also in the central lab, in the local labs, you had the majority of the patients between 1 and 10%, and about 19 patients or so who had less than 1%. And then in the central lab, the number of slides reviewed were a little lower than the local review at this point in time – that will change – and we saw very similar, kind of, breakdown.

And what we did see what that the response rates were pretty high. In the less than 1%, the overall response rate was 84%, with about 50% CRs, in the 1 to 10%, the overall response rate was about 78%, with about 58% CRs. So, in other words, even in this patient population where the CD30 expression was not very high, you are seeing responses with this CHP-BV regimen. Of course, it’s not a randomized study, but these are more patients than what was seen in the ECHELON-2 study, and the signals are pretty clear that at least that CD30 is important, but what cells express CD30 is also even more important – and that’s the unknown question hopefully this study will be able to answer.