In San Antonio, we are very proud to present trastuzumab deruxtecan trial, that is the DEBRRAH trial. It’s an initiative investigator trial that was made it possible by the collaboration and all the work with MedSIR and also sponsored by Daiichi Sankyo and AstraZeneca.
In this trial, what we are testing is the role of trastuzumab deruxtecan in HER2-positive and HER2-low expressing advanced breast cancer in patients with central nervous system involvement, either brain metastasis or leptomeningeal carcinomatosis...
In San Antonio, we are very proud to present trastuzumab deruxtecan trial, that is the DEBRRAH trial. It’s an initiative investigator trial that was made it possible by the collaboration and all the work with MedSIR and also sponsored by Daiichi Sankyo and AstraZeneca.
In this trial, what we are testing is the role of trastuzumab deruxtecan in HER2-positive and HER2-low expressing advanced breast cancer in patients with central nervous system involvement, either brain metastasis or leptomeningeal carcinomatosis. In this trial, we have five cohorts. We divided patients by HER2-positive status or HER2-low expressing status; by previous local treatment or not, either surgery, radiosurgery, or whole brain radiotherapy; and if the patients are progressing, either after local treatment or without previous local treatment. I think this is the key aspects that are very interesting in our trial. We also have cohorts that is special for patients with leptomeningeal carcinomatosis, either HER2-positive or HER2-low expressing.
For San Antonio, we are very happy to bring the very first results on this trial. We present the results on Cohort 1 and Cohort 3. We started this trial in June last year. Even with the pandemics, we were able to have a fast recruitment, which I thank to the investigators from the DEBBRAH study. We had a first cut-off in September this year where we were able to analyze these two cohorts. These Cohorts 1 and 3, are both in patients with HER2-positive breast cancer and after local therapy. Cohort 1 in patients with no progression after local therapy and Cohort 3 in patients progressing after local therapy. I think this is new in the clinical practice and in clinical trials.
For Cohort 1, our primary objective was PFS at 16 weeks and it was reached. We have seven out of eight patients non-progressing at 16 weeks. Then for Cohort 3, the primary objective was overall response rate, which was 44.4%. I remind you that these are patients progressing after local treatment, which are very exciting results for this cohort of patients. Of course, we have a short follow-up of only less than nine months. We have time then for present more mature results in the future, but I think these are very exciting for now.
Just a brief question; it’s about the safety. We approved once again that trastuzumab is safe. The Grade 3 and 4 side effects that we have, the majority of them, were neutropenia or fatigue, which are manageable. Also, pneumonitis were only at one patient with pneumonitis; that is the great deal with trastuzumab deruxtecan. It was a great one. It was solved and the patient is fine from results from pneumonitis. So, I think that our data were very promising. We are waiting anxiously to finish this trial and to have all the data more mature. But I think that for now, it’s very exciting data and we are very happy to present it.