LONSURF is specifically a combination drug of trifluridine, a nucleoside metabolic inhibitor, and tipiracil, a thymidine phosphorylase inhibitor, used to treat adult patients with: metastatic colorectal cancer who have been previously treated with medicine fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF biological therapy, and if RAS wild-type, an anti-EGFR therapy. metastatic gastric or gastroesophageal junction adenocarcinoma previously treated with minimum two prior lines of chemotherapy that included a fluoropyrimidine, a platinum, either a taxane or irinotecan, and if apt, HER2/neu-targeted therapy.
Dosage: The recommended dosage of lonsurf is 35 mg/m2 up to a maximum of 80 mg per dose (based on the trifluridine component) orally twice daily with food on Days 1 through 5 and Days 8 through 12 of each 28-day cycle until the disease is progressive or unacceptable toxicity occurs. Round dose to the nearest 5 mg increment. Instruct patients to swallow lonsurf tablets whole. Instruct patients not to retake doses of lonsurf that are vomited or missed and to continue with the next scheduled dose.
Side Effects: The most commonly reported trifluridine side effects include:
- Decreased appetite
Warnings and Precautions:
- Obtain complete blood counts prior to and on Day 15’th of each cycle of lonsurf 20mg and more frequently as clinically indicated.
- Monitor patients with lonsurf for complete blood cell counts before and on Day 15 of each cycle. For potential genotoxicity, males with female partners of reproductive potential are advised to use condoms while on treatment with this drug and for at least 90 days after the last dose.
- Do not initiate treatment with lonsurf chemotherapy in patients with baseline moderate or severe hepatic impairment.
- Women are advised not to breastfeed while on the treatment with this medication and for one day following the final dose.