Dr. Andrew Roberts out of Peter Mac or Royal Melbourne Hospital in Melbourne, Australia did some of the early basic science research on venetoclax. During our interview at the European Hematology Association Annual Congress held in Copenhagen in June 2016, he reported on the update of the first published study of any combination with venetoclax, in this case with rituximab in relapsed and refractory CLL patients
The results are encouraging, even for the 50% patients who have failed rituximab in the past.
Take Away Points:
- Overall response rate (ORR) was 86% in the 49 patients studied.
- Approximately half of patients reached a complete remission. That is much higher than with monotherapy.
- Most remissions were noted at restaging with only 7 months of treatment.
- 11 of 13 patients who stopped the treatment after reaching MRD negativity (where there was no detectable disease even with sophisticated testing (flow cytometry in this study) for one cell or fewer in 10,000) remained disease free. The patients who did progress will likely respond to a second challenge with venetoclax.
- The depth of response is deeper with the combination than with single agent venetoclax leading to more durable remissions and the possibility of stopping therapy
We still have a long way to go before we fully understand how to best use these new medications, but clearly combination therapy of a finite duration and leads to very deep remissions (MRD-negativity) is increasingly being recognized as an important therapeutic goal.
Venetoclax is only approved for monotherapy at this time so our only access to these potent combinations and the only way we are going to learn which combinations are the safest and work the best will be through clinical trials.
Dr. Hallek discussed this topic in a general way at the same Congress in this interview about the unmet needs in CLL.
Here is the link to the abstract that Dr. Roberts references of the specific combination of venetoclax and rituximab.
Here is a link to our interview.
And finally here are two related abstracts on the venetoclax/rituximab combination by Dr. Roberts from the same EHA Congress that fill in more on the details:
This is very exciting news. We are moving forward quickly, but there is much left to do.
Brian Koffman, MD