Celgene UK has announced that preliminary clinical data from a phase III, randomized, double-blind study of elderly patients newly diagnosed with multiple myeloma, were presented during the 51st American Society of Hematology’s annual meeting in New Orleans, LA.
The study of 459 patients, 65 years or older, evaluated patients receiving Revlimid in combination with melphalan and prednisone, followed by Revlimid alone (MPR-R) (n=152); patients receiving Revlimid in combination with melphalan and prednisone, followed by placebo (MPR) (n=153); and patients receiving placebo, melphalan and prednisone, followed by placebo (MP) (n=154). Patients were offered Revlimid therapy if they progressed while participating in the study.
The primary endpoint of the study was to determine the improvement of progression free survival (PFS) in patients who received MPR-R versus patients who received MP. Two interim analyses were planned as part of the study and an independent adjudication committee confirmed responses to therapy as well as progressions.
At the first interim analysis (median follow-up of 9.4 months), the Independent Data Monitoring Committee informed Celgene that the PFS comparison of MPR-R versus MP had crossed the pre-specified O’Brien-Fleming superiority boundary.
A significant improvement was shown in PFS, the primary endpoint of the study. The median PFS of MPR-R had not been reached, while the MP arm had a median PFS of 13.0 months (p<0.001). Patients treated with MPR-R had a 50 percent reduction in the risk of disease progression compared to MP – one of the highest reported risk reduction compared to MP of any phase III study in newly diagnosed multiple myeloma to date.
The overall response rate for patients in the MPR-R arm was 77% versus 49% for patients in the MP arm (p<0.001). This included complete response (CR) rates of 18% for MPR-R versus 5% for MP (p=0.001); very good partial response (VGPR) rates of 32% for MPR-R versus 11% for MP (p=0.001); and partial response (PR) rates of 45% for MPR-R versus 37% for MP. The median time to first response was 1.9 months for MPR-R versus 2.8 months for MP (p<0.001).
The study reported that all patients had a one year overall survival rate of 92%, one of the highest one year overall survival reported in a study comparing the addition of novel therapy to MP, even though this study had more patients with poorer prognosis than other studies.
The value of continuous Revlimid was supported by a secondary comparison of MPR followed by continuous Revlimid (MPR-R) versus MPR of fixed duration (MPR). Patients received Revlimid, melphalan and prednisone for nine cycles and were then randomized either to continuous Revlimid therapy or placebo from cycle 10 forward.
Patients who received continuous Revlimid therapy from cycle 10 onwards had a 75% reduction in the risk of progression compared to those who received placebo after nine fixed cycles (MPR).
The most common Grade 3 or 4 haematological adverse events experienced by patients in the study included neutropaenia (70% MPR-R vs. 31% MP) and thrombocytopaenia (38% MPR-R vs. 13% MP). T
These adverse events were manageable. Grade 3 or 4 non-hematological adverse events included gastrointestinal (8% MPR-R vs. 4% MP), deep-vein thrombosis (7% MPR-R vs. 2% MP), fatigue (7% MPR-R vs. 4% MP) and rash (4% MPR-R vs. 2% MP). No Grade 3 or 4 peripheral neuropathy was experienced by patients in this study. From cycle 10 onwards, less than 5% new grade 3 or 4 haematological or non-haematological adverse events were reported on MPR-R compared to 5% anaemia seen on MP.