Efficacy and Safety of Carfilzomib in Combination With Ibrutinib vs Ibrutinib in Waldenström's Macroglobulinemia
brief summary
In Waldenström macroglobulinemia (WM) chemotherapy induces only low CR/VGPR (Complete Remission/ Very Good Partial Response) rates and responses of short duration compared to other indolent lymphomas. Thus, innovative approaches are needed which combine excellent activity and tolerability in WM. Chemotherapy-free approaches are highly attractive for this patient group. Based on its high activity in WM and its low toxicity, Ibrutinib was approved for the treatment of WM by the European Medicines Agency (EMA). However, also Ibrutinib fails to induce CRs and the VGPR rate is 16% in relapsed patients. In addition, activity of Ibrutinib depends on the genotype: compared to MYD88mut/CXCR4WT patients Ibrutinib single agent therapy induces substantially lower response rates in patients with the MYD88mut/CXCR4mut or the MYD88WT/CXCR4WT genotype (major response (at least PR) in 91.7 % compared to 61.9 and 0 %, respectively). Phase II data have indicated that the proteasome inhibitor Carfilzomib is able to overcome the inferior prognosis of Ibrutinib in MYD88mut/CXCR4mut and MYD88WT/CXCR4WT patients, as response rates were high for all genotypes in a phase II study combining Carfilzomib with Rituximab and Dexamethasone. Based on this the investigators hypothesize that addition of Carfilzomib to Ibrutinib will increase the VGPR/CR rate compared to Ibrutinib alone in patients with WM, in particular in patients carrying the CXCR4 mutation. In addition, the investigators hypothesize, that the combination Carfilzomib and Ibrutinib will be also highly active in MYD88 wildtype patients and that this combination will be at least as efficient in treatment naïve patients as in relapsed/refractory patients.
detailed description
In Waldenström macroglobulinemia (WM) conventional chemotherapy induces only low Complete Remission (CR) rates and responses of short duration compared to other indolent lymphomas. Thus, innovative approaches are needed which combine excellent activity and tolerability in patients with WM, who are mostly of advanced age. Today, chemotherapy in combination with the anti-CD20 antibody Rituximab is still the backbone of treatment in patients with WM and is recommended as first line in national and international treatment guidelines.With the approval of Ibrutinib by the EMA 2015 for patients with relapsed WM or for patients not eligible for chemotherapy with treatment naïve WM treatment landscape has changed in this lymphoma subtype and there is an urgent need to evaluate to which extent chemotherapy-free approaches add clinical benefit to the patient. Based on its high activity in WM and its low toxicity, Ibrutinib was approved for the treatment of WM by the EMA. However, also Ibrutinib fails to induce CRs and the VGPR (Very Good Partial Response) rate is 16% in relapsed patients. In addition, activity of Ibrutinib depends on the genotype with inferior response rates in MYD88mut/CXCR4mut patients and in patients with unmutated MYD88 and CXCR4 compared to MYD88mut/CXCR4WT patients (major response (at least PR) in 91.7 % compared to 61.9 and 0 %, respectively). Phase II data have indicated that the proteasome inhibitor Carfilzomib is able to overcome the inferior prognosis of Ibrutinib in MYD88mut/CXCR4mut and MYD88WT/CXCR4WT patients, as response rates were high for all genotypes in a phase II study combining Carfilzomib with Rituximab and Dexamethasone. Based on this the investigators hypothesize that addition of Carfilzomib to Ibrutinib will increase the VGPR/CR rate compared to Ibrutinib alone in patients with WM, in particular in patients carrying the CXCR4 mutation. In addition, the investigators hypothesize, that the combination Carfilzomib and Ibrutinib will be also highly active in MYD88 wildtype patients and that this combination will be at least as efficient in treatment naïve patients as in relapsed/refractory patients.
The study is an international, phase II, multicenter, open label and randomized trial comparing Carfilzomib in combination with Ibrutinib (treatment Arm A) versus Ibrutinib (treatment arm B) in male or female patients aged ≥ 18 years of de novo and relapsed/refractory WM in need of treatment.
The phase II study will consist of an open labeled, stratified 1:1 randomization between Arm A and Arm B. Stratification factors are MYD88 and CXCR4 status (positive vs. negative) and number of prior lines (0 vs. ≥ 1 treatment lines). A stratified central block randomization will be used.
The primary objective of the trial is to test the efficacy and toxicity of Carfilzomib and Ibrutinib in patients with treatment naïve or relapsed WM.
official title
Efficacy and Safety of Carfilzomib in Combination With Ibrutinib vs Ibrutinib Alone in Waldenström's Macroglobulinemia (CZAR-1)