The STRATUS trial (MM-010): A single-arm phase 3b study of pomalidomide plus low-dose dexamethasone (POM + LoDEX) in refractory or relapsed and refractory multiple myeloma.

TPS8625 Background: POM is a distinct oral IMiD immunomodulatory agent with direct anti-myeloma, stromal cell support-inhibitory, and immune-modulating activities. In the phase 3 MM-003 trial, POM + LoDEX significantly extended progression-free survival (PFS) and overall survival (OS) vs. high-dose dexamethasone in patients (pts) who failed bortezomib (BORT) and lenalidomide (LEN) treatment (Tx; Dimopoulos, ASH 2013). STRATUS is a multicenter, single-arm, open-label phase 3b trial with > 85 sites across Europe to further evaluate safety and efficacy and explore cytogenetics, pharmacokinetics (PK), and biomarkers in a large pt population (target enrollment: 720 pts; NCT01712789). Methods: Eligible pts have refractory or relapsed and refractory disease, having failed BORT and LEN and received adequate prior alkylator therapy. Key exclusion criteria include absolute neutrophil count < 800/μL, platelet count < 75,000 or 30,000/μL (for pts with < 50% or > 50% of bone marrow nucleated cells as plasma cells, respectively), creatinine clearance < 45 mL/min, hemoglobin < 8 g/dL, and peripheral neuropathy > grade 2. POM is administered 4 mg D1-21/28-day cycle and LoDEX 40 mg/day (20 mg for pts aged > 75 yrs) on D1, 8, 15, and 22 until progressive disease or unacceptable toxicity. All pts receive low-dose ASA or equivalent thromboprophylaxis. Upon Tx discontinuation, follow-up will continue up to 5 yrs from enrollment of last pt for survival, second primary malignancies, and subsequent anti-MM Tx. The primary endpoint is safety. Secondary endpoints include POM exposure, PK, efficacy (overall response rate, time to response, duration of response, PFS, time to progression, OS, and cytogenetics). Cytogenetics are collected at initial diagnosis, study entry, and upon discontinuation to better understand the evolution of cytogenetics throughout the disease course and elucidate the role of POM in pts with different cytogenetic profiles. As exploratory endpoints, bone marrow and blood samples are collected for biomarker analysis to predict response or resistance to POM Tx. As of Jan 22, 2014, 400 pts have been enrolled and enrollment continues. Clinical trial information: NCT01712789.