Patients with refractory or relapsed and refractory
multiple myeloma who no longer receive benefit from novel agents have limited treatment options and short expected survival. del(17p) and t(4;14) are correlated with shortened survival. The phase 3 MM-003 trial demonstrated significant progression-free and overall survival benefits from treatment with
pomalidomide plus low-dose
dexamethasone compared to high-dose
dexamethasone among patients in whom
bortezomib and
lenalidomide treatment had failed. At an updated median follow-up of 15.4 months, the progression-free survival was 4.0 versus 1.9 months (HR, 0.50; P<0.001), and median overall survival was 13.1 versus 8.1 months (HR, 0.72; P=0.009).
Pomalidomide plus low-dose
dexamethasone, compared with high-dose
dexamethasone, improved progression-free survival in patients with del(17p) (4.6 versus 1.1 months; HR, 0.34; P <0.001), t(4;14) (2.8 versus 1.9 months; HR, 0.49; P=0.028), and in standard-risk patients (4.2 versus 2.3 months; HR, 0.55; P<0.001). Although the majority of patients treated with high-dose
dexamethasone took
pomalidomide after discontinuation, the overall survival of patients treated with
pomalidomide plus low-dose
dexamethasone or high-dose
dexamethasone was 12.6 versus 7.7 months (HR, 0.45; P=0.008) in patients with del(17p), 7.5 versus 4.9 months (HR, 1.12; P=0.761) in those with t(4;14), and 14.0 versus 9.0 months (HR, 0.85; P=0.380) in standard-risk subjects. The overall response rate was higher in patients treated with
pomalidomide plus low-dose
dexamethasone than in those treated with high-dose
dexamethasone both among standard-risk patients (35.2% versus 9.7%) and those with del(17p) (31.8% versus 4.3%), whereas it was similar in patients with t(4;14) (15.9% versus 13.3%). The safety of
pomalidomide plus low-dose
dexamethasone was consistent with initial reports. In conclusion,
pomalidomide plus low-dose
dexamethasone is efficacious in patients with relapsed/refractory
multiple myeloma and del(17p) and/or t(4;14). This study is registered at ClinicalTrials.gov as NCT01311687 and with EudraCT as 2010-019820-30.