In April 2017, the National Sanitary Surveillance Agency (ANVISA-Brazil) approved lenalidomide (LEN) for multiple myeloma (MM) and myelodysplastic syndrome. ANVISA had rejected the first application in 2010, and denied a request for reconsideration in 2012. The reason for rejection was the lack of comparative effectiveness studies proving that LEN was more effective than thalidomide (THAL), a strictly controlled drug regulated by Federal law 10.651/2003 and dispensed to patients (at no costs) through public health system units and hospitals. ANVISA unexplained retreat on the LEN approval for marketing was an unquestionable triumph of the lobbying that ensued the denial, at the forefront of which were politicians, Congress members, patient organizations and medical societies. Two randomized (phase III) trials and three observational (case-control and population-based cohort) compared the effectiveness of THAL- versus LEN-based therapies in MM. Overall, these studies showed no difference in efficacy between LEN- and THAL-based therapies. LEN caused less neuropathy, and more severe hematologic adverse effects. It is much costlier than THAL, and substitution of THAL by LEN shall raise considerably public healthcare costs in Brazil.