This is Shebli Atrash from the Levine Cancer Institute in Charlotte. I will be talking about the final results of phase 1, belantamab mafodotin in combination with carfilzomib, lenalidomide, and dexamethasone for patients after at least one line of prior treatment for multiple myeloma.
We enrolled in this trial about 19 patients. We did it in a dose escalation fashion, followed by dose expansion. Patients with at least one prior line of treatment were enrolled. Most of our patients received 1 to 3 prior lines. Baseline characteristics were very diverse for our population, representing our population in Charlotte. We had about 30% African-American patients enrolled in the trial.
With the first dose of 1.4mg/kg, given every two cycles, that would be every eight weeks, we encountered one dose-limiting toxicity of thrombocytopenia. Suffice to say that this patient continued to be on the trial and had a very deep response, MRD negative, 10 to -6, with the second dose. After six patients were enrolled, we cleared that dose and moved on to the second dose, which is 1.9mg/kg. We did not see any dose-limiting toxicity at that dose.
We also included an expansion phase. We enrolled an additional six patients to confirm the efficacy and safety of the selected dose. We did not encounter any dose-limiting toxicities. Regarding the overall toxicities, they were mainly hematological, with no increase in signal of increased infections. However, it's important to note that keratopathy was present in about 95% of the patients, as expected from belantamab mafodotin. It was reversible. Grades were better than with every three weeks dosing. We included a dose hold if a patient has grade two or higher keratopathy to allow for full recovery prior to starting belantamab mafodotin.
So 100% of the patients received the first dose of belantamab mafodotin. For subsequent doses, it ranged between 30% and 70% of the patients who got their doses, with an average of about 50% of the patients able to get their subsequent doses successfully.
In terms of the efficacy of the treatment, we have seen 100% response rates. More than half the patients were in stringent complete response with MRD negative disease, to the level of 10 to -6 as measured by flow cytometry. Those results are very encouraging. We have already opened our phase 2 portion of this trial.
Our phase 2 will be focusing on newly diagnosed multiple myeloma patients with high-risk disease. We believe that we could do better in this subgroup of patients in order to improve progression-free survival and overall survival. The phase 2 portion of the trial is going to involve multiple centers. We will include four cycles of belantamab, KRd, and then allow for stem cell collection, followed by another four cycles before proceeding with stem cell transplant, if the patient is transplant eligible. Then we'll follow with KR and belantamab mafodotin maintenance for up to about 20 cycles before we move on to physician choice of maintenance, whether with lenalidomide or with carfilzomib and lenalidomide combination.
Most of the recommendations will come out based on the MRD negativity rates at the end of the triplet maintenance approach.
HealthTree • December 17, 2024