Eisen 2010.

Study characteristics
Methods	Phase II/III parallel‐group RCT. Double‐blind study. Multicentre trial.
Participants	Previously treated metastatic melanoma. Participants randomised: 306.
Interventions	Two‐arm trial: Lenalidomide 25 mg orally days 1 to 21 of a 28‐day cycle (N = 152); Placebo (N = 154).
Outcomes	Progression‐free survival. Overall survival. Tumour response. Toxicity.
Notes	Cross‐over: not reported. Quality of life: not investigated. Participants with brain metastasis: excluded. Median follow‐up: not available.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Patients were randomized using an interactive voice response system". Comment: Risk was likely low because this was a multicentre trial with centralised randomisation.
Allocation concealment (selection bias)	Low risk	Risk was likely low because this was a multicentre trial with centralised randomisation.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Double‐blind". Comment: This method makes low the risk of performance bias
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Double‐blind". Comment: This method makes low the risk of detection bias
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing outcome data were balanced across intervention groups, with similar reasons for missing data across groups.
Selective reporting (reporting bias)	Low risk	No differences between protocol and published report.
Other bias	Low risk	The study appeared to be free of other sources of bias.