Regorafenib

Regorafenib is an orally-administered inhibitor of multiple kinases. It is used for the treatment of metastatic colorectal cancer, advanced gastrointestinal stromal tumours, and hepatocellular carcinoma.

Regorafenib is a kinase inhibitor used to treat patients with metastatic colorectal cancer, unresectable, locally advanced, or metastatic gastrointestinal stromal tumors, and hepatocellular carcinoma.

Regorafenib is indicated for the treatment of patients with metastatic colorectal cancer (CRC) who have been previously treated with fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF therapy, and, if KRAS wild type, an anti-EGFR therapy. Regorafenib is also indicated for the treatment of patients with locally advanced, unresectable or metastatic gastrointestinal stromal tumour (GIST) who have been previously treated with imatinib mesylate and sunitinib malate. Regorafenib is also indicated for the treatment of patients with hepatocellular carcinoma (HCC) previously treated with sorafenib.

• Hepatocellular Carcinoma
• Metastatic Colorectal Cancer (MCRC)
• Metastatic Gastrointestinal Stromal Tumor
• Locally advanced Gastrointestinal stromal tumor
• Unresectable Gastrointestinal stromal tumor

Regorafenib is a small molecule inhibitor of multiple membrane-bound and intracellular kinases involved in normal cellular functions and in pathologic processes such as oncogenesis, tumor angiogenesis, and maintenance of the tumor microenvironment. In in vitro biochemical or cellular assays, regorafenib or its major human active metabolites M-2 and M-5 inhibited the activity of RET, VEGFR1, VEGFR2, VEGFR3, KIT, PDGFR-alpha, PDGFR-beta, FGFR1, FGFR2, TIE2, DDR2, TrkA, Eph2A, RAF-1, BRAF, BRAFV600E , SAPK2, PTK5, and Abl at concentrations of regorafenib that have been achieved clinically. In in vivo models, regorafenib demonstrated anti-angiogenic activity in a rat tumor model, and inhibition of tumor growth as well as anti-metastatic activity in several mouse xenograft models including some for human colorectal carcinoma.

Cmax = 2.5 μg/mL; Tmax = 4 hours; AUC = 70.4 μgh/mL; Cmax, steady-state = 3.9 μg/mL; AUC, steady-state = 58.3 μgh/mL; The mean relative bioavailability of tablets compared to an oral solution is 69% to 83%.

Regorafenib undergoes enterohepatic circulation with multiple plasma concentration peaks observed across the 24-hour dosing interval.

Regorafenib is highly bound (99.5%) to human plasma proteins.

Approximately 71% of a radiolabeled dose was excreted in feces (47% as parent compound, 24% as metabolites) and 19% of the dose was excreted in urine (17% as glucuronides) within 12 days after administration of a radiolabeled oral solution at a dose of 120 mg.

Regorafenib, 160 mg oral dose = 28 hours (14 - 58 hours); M2 metabolite, 160 mg oral dose = 25 hours (14-32 hours); M5 metabolite, 160 mg oral dose = 51 hours (32-72 hours);

The most common adverse reactions (≥20%) are asthenia/fatigue, HFSR, diarrhea, decreased appetite/food intake, hypertension, mucositis, dysphonia, and infection, pain (not otherwise specified), decreased weight, gastrointestinal and abdominal pain, rash, fever, and nausea

• Avoid grapefruit products. Grapefruit inhibits CYP3A4 metabolism, which may increase the serum levels of regorafenib.
• Avoid St. John's Wort. This herb induces CYP3A4 metabolism, which may reduce serum levels of regorafenib.
• Take after a meal. Should be taken following a low-fat meal containing less than 600 calories and less than 30% fat.
• Take at the same time every day.