Sunitinib treatment in a patient with metastatic renal cell carcinoma and bariatric surgery

In the past decade, many tyrosine kinase inhibitors (TKI) were added to the arsenal of oral oncolytics used in the treatment of a variety of malignancies. In contrary to intravenous drugs, the bioavailability of orally administered drugs depends on gastrointestinal absorption and first-pass metabolism. Challenges in reaching effective plasma levels may arise in patients with altered gastrointestinal anatomy, while pharmacokinetics can differ. In this case report, we demonstrate a patient with a history of gastric bypass surgery due to obesity and an indication for treatment with sunitinib for metastatic renal cell carcinoma (mRCC). Since the plasma concentration of sunitinib and its active metabolite desethylsunitinib appeared to be inadequate during the standard treatment regimen, the sunitinib dose was successfully escalated.