You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Brand", "UnapprovedDrug", "Drug", "DrugGroup"].

Please return the output as a JSON object of the format: {"Brand" : ["Aspirin", ...], "DrugGroup": ["Salicyclate", ...], "Drug": ["Phenobarbital", ...], "UnapprovedDrug": ["Heroin", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Results from human in vitro metabolism studies and nonclinical studies show that REVLIMID  (lenalidomide) is neither metabolized by nor inhibits or induces the cytochrome P450 pathway suggesting that lenalidomide is not likely to cause or be subject to P450-based metabolic drug interactions in man. Co-administration of multiple doses of 10 mg of lenalidomide had no effect on the single dose pharmacokinetics of R- and S- warfarin. Co-administration of single 25-mg dose warfarin had no effect on the pharmacokinetics of total lenalidomide. Expected changes in laboratory assessments of PT and INR were observed after warfarin administration, but these changes were not affected by concomitant lenalidomide administration.
{"Brand": ["REVLIMID"], "Drug": ["lenalidomide", "R- warfarin", "S- warfarin", "warfarin"], "DrugGroup": [], "UnapprovedDrug": []}