> ## Content Index
> Fetch the complete content index at: https://www.fdaweb.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# No Lonsurf Carve-Out: Taiho Petition
- URL: https://www.fdaweb.com/no-lonsurf-carve-out-taiho-petition/
- Published: 2020-05-05T12:00:00.000Z
- Updated: 2026-09-14T16:13:42.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5146721

Taiho Oncology is asking FDA not to permit companies to carve out of the approved Lonsurf (trifluridine and tipiracil) labeling the language that relates to dose reduction in severely renally impaired patients. “The carving out of dose reductions in severely renally impaired patients will result in labeling that will present an increased safety risk and that will render the proposed drug less safe,” a Taiho 4/28 [petition](https://www.regulations.gov/contentStreamer?documentId=FDA-2020-P-1312-0001&attachmentNumber=1&contentType=pdf&ref=fdaweb.com) says.

The petition says FDA required Taiho to conduct a post-marketing study to evaluate the safety, tolerability, and pharmacokinetics of Lonsurf’s individual components and the major metabolite of trifluridine in advanced solid tumor (other than breast cancer) patients with varying degrees of renal impairment following single-dose and multiple-dose administration of the drug.

“Given that this study was an FDA mandated post-marketing requirement, the completion of the study and revision of the labeling to include a reduction of the dose in severely renally impaired patients was critical to safely dose Lonsurf in this patient subpopulation,” Taiho says. “FDA must not permit an ANDA applicant \[to\] carve out this important information out of the labeling as the resultant labeling will make the proposed generic product less safe and effective than the reference product, Lonsurf.”