From the Guidelines
Yes, Lonsurf (trifluridine/tipiracil) is a type of chemotherapy medication used primarily to treat metastatic colorectal cancer and gastric cancer. It is typically prescribed for patients who have already tried other chemotherapy regimens. Lonsurf works through a dual mechanism: trifluridine incorporates into DNA to disrupt cell division, while tipiracil prevents the rapid breakdown of trifluridine in the body, allowing it to remain active longer. The standard dosing is based on body surface area, usually 35 mg/m² twice daily on days 1-5 and 8-12 of a 28-day cycle. Common side effects include bone marrow suppression (resulting in low blood counts), nausea, fatigue, and diarrhea. Regular blood tests are necessary during treatment to monitor for these effects. Unlike traditional intravenous chemotherapy, Lonsurf is taken orally as tablets, which allows patients to take it at home rather than requiring hospital visits for administration. Some key points to consider when prescribing Lonsurf include:
- The trifluridine and tipiracil regimen was approved by the FDA in 2019 for previously treated recurrent or metastatic gastric and EGJ adenocarcinoma, based on results from the global phase III TAGS trial 1.
- In the TAGS trial, Lonsurf significantly improved median overall survival (OS) by 2.1 months compared to placebo (5.7 vs 3.6 months) 1.
- Lonsurf is recommended as a preferred category 1 treatment option for patients with recurrent or metastatic gastric cancer in the third-line or subsequent setting 1.
- The most frequently reported grade 3–4 toxicities with Lonsurf were neutropenia (38%), leukopenia (21%), anemia (19%), and lymphocytopenia (19%) 1. It's also worth noting that Lonsurf did not result in any partial or complete responses and produced substantial grade 3–4 toxicities, so this treatment should be considered for a very select population of patients with low-volume gastric cancer who have minimal or no symptoms and the ability to swallow pills 1. In the context of gastric cancer treatment, other recommended regimens for second-line or subsequent therapy include irinotecan and cisplatin, ramucirumab combined with irinotecan or FOLFIRI, and irinotecan and docetaxel (category 2B) 1. However, trifluridine/tipiracil has the strongest evidence base following the phase III TAGS trial for third-line treatment 1. Overall, Lonsurf is a valuable treatment option for patients with metastatic colorectal cancer and gastric cancer who have already tried other chemotherapy regimens.
From the FDA Drug Label
LONSURF is a cytotoxic drug. The answer to the question is yes, Lonsurf is considered a chemotherapy drug, as it is classified as a cytotoxic drug. This is directly stated in the drug label 2.
- Key points:
- Lonsurf is a combination of trifluridine and tipiracil.
- It is indicated for the treatment of adult patients with metastatic colorectal cancer and metastatic gastric or gastroesophageal junction adenocarcinoma.
- The drug label explicitly states that Lonsurf is a cytotoxic drug, which is a type of chemotherapy.
From the Research
Definition of Lonsurf
- Lonsurf, also known as trifluridine/tipiracil, is a novel, orally active, antimetabolite agent comprised of trifluridine, a thymidine-based nucleoside analogue, and tipiracil, a potent thymidine phosphorylase inhibitor 3.
Mechanism of Action
- Trifluridine is incorporated into DNA via phosphorylation, ultimately inhibiting cell proliferation 3.
- Tipiracil increases systemic exposure of trifluridine when coadministered 3.
Classification as Chemotherapy
- Lonsurf is classified as a form of chemotherapy, specifically an oral fluoropyrimidine 4.
- It is used to treat metastatic colorectal cancer in patients who are refractory to or are not considered candidates for current standard chemotherapy and biological therapy 3.
Treatment Regimen
- The approved regimen of oral twice-daily trifluridine/tipiracil (35 mg/m2 twice daily on days 1-5 and 8-12 of each 28-day cycle) significantly improved overall survival and progression-free survival 3.
- Lonsurf is typically used after standard chemotherapy treatments, including fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy 5.