Related Experiment Video
Updated: Jul 12, 2025

Establishment and Characterization of Patient-Derived Xenograft Models of Anaplastic Thyroid Carcinoma and Head and Neck Squamous Cell Carcinoma
Published on: June 2, 2023
Planned drug holidays during treatment with lenvatinib for radioiodine-refractory differentiated thyroid cancer: a
Chihiro Matsuyama1,2, Tomohiro Enokida3, Yuri Ueda3,4
1Department of Pharmacy, National Cancer Center Hospital East, Kashiwa, Japan.
Background:
In the phase 3 SELECT study, lenvatinib significantly improved prognostic outcomes vs. placebo in patients with radioiodine-refractory differentiated thyroid cancer (RR-DTC). However, toxicity of lenvatinib is sometimes considerable and requires frequent dose interruptions and modifications. Recently, planned drug holidays have been proposed as a means of avoiding severe adverse events (AEs).
Methods:
We retrospectively reviewed medical records to compare the efficacy and safety of lenvatinib in RR-DTC patients who underwent planned drug holidays (planned holiday group) vs. those who received conventional daily oral administration (daily group).
Results:
The subjects were 25 patients in the planned holiday group and 21 in the daily group. Median age was 73 years (range 43-84) and 62 years (range 42-75), and histologic subtype of papillary/follicular was 21/4 cases and 15/6 cases, respectively. Time to treatment failure (TTF) and overall survival (OS) were significantly longer in the planned holiday group than the daily group (not reached [NR] vs. 14.9 months, hazard ratio [HR] 0.25, 95% confidence interval [Cl] 0.11-0.58, p<0.001; NR vs. 26.6 months, HR 0.20, 95% CI 0.073-0.58, p=0.001, respectively). Median progression-free survival (PFS) was NR in the planned holiday group vs. 15.1 months in the daily group (HR 0.31, 95% CI 0.14-0.68, p=0.002). Duration of the period with lenvatinib dose ≥10 mg was significantly longer in the planned holiday group (NR vs. 6.5 months, HR 0.22, 95% CI 0.10-0.49, p<0.001), and the frequency of drug interruption due to intolerable AEs was lower (68.0% vs. 95.2%, p=0.027).
Conclusion:
Planned drug holidays for lenvatinib demonstrated significantly longer PFS, TTF, and OS than daily oral administration, and less intolerable toxicity leading to further unplanned treatment interruption. These benefits were apparently associated with a more extended period of lenvatinib administration at ≥10 mg. These findings might contribute to a favorable patient prognosis and safer toxicity profile.
Related Concept Videos
Drugs for Treatment of Diarrhea-Predominant IBS
Two specific drugs used in the treatment are alosetron (Lotronex) and eluxadoline (Viberzi). Alosetron, a 5-HT3 antagonist, works by slowing the movement of stools in the gut, reducing bowel...
Drug Administration and Therapy Phases: Overview
The pharmaceutical phase focuses on leveraging the physicochemical properties of the drug to design and manufacture an effective product. Variants include orally administered tablets or capsules, topical creams or ointments, and parenteral-delivery solutions or emulsions.
The pharmacokinetic phase...
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Hepatic Drug Excretion: Enterohepatic Cycling
Post-release drugs and metabolites can be reabsorbed into the body from the intestine. For conjugated metabolites like glucuronides, reabsorption requires enzymatic hydrolysis by intestinal microflora. This...
Targeted Cancer Therapies
There are several types of targeted therapies against...
Dosage Regimen: Fixed Dose
Fixed-dose regimens can be used for various routes of administration, including intravenous (IV) injections and oral medications. For IV administration, a predetermined amount of the drug is...

