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Xermelo

telotristat ethyl
Tryptophan Hydroxylase Inhibitor TerSera Therapeutics FDA Approved 2017
Indications Dosing Forms Contraindications Warnings Adverse Reactions Pharmacology Clinical Studies Tumor Types
1. Indications and Usage

Carcinoid syndrome diarrhea in combination with somatostatin analog (SSA) therapy in adults inadequately controlled by SSA therapy alone.

2. Dosage and Administration

250 mg orally three times daily with food
Use in combination with a somatostatin analog
Dose reduction for hepatic impairment (Child-Pugh C): 250 mg once daily

3. Dosage Forms and Strengths

Tablets: 250 mg (equivalent to 228.5 mg telotristat etiprate)

4. Contraindications

None listed.

5. Warnings and Precautions
  • Constipation: In 6% (can be severe). Monitor and manage proactively. Reduce dose or D/C if severe constipation develops.
  • Depression: In 3%. Monitor for depressed mood. Discontinue if depression worsens.
  • Hepatic Enzyme Elevations: ALT/AST elevations reported. Monitor LFTs before and during treatment.
6. Adverse Reactions
Most Common Adverse Reactions

Nausea (13%), headache (11%), elevated GGT (9%), depression (9%), peripheral edema (7%), flatulence (6%), decreased appetite (7%), constipation (6%), abdominal pain (6%), pyrexia (5%)

Nausea
13%
Headache
11%
Elevated Ggt
9%
Depression
9%
Peripheral Edema
7%
Decreased Appetite
7%
Flatulence
6%
Constipation
6%
Abdominal Pain
6%
Pyrexia
5%

Consult the complete prescribing information for a comprehensive list of adverse reactions and their frequencies.

12. Clinical Pharmacology
Mechanism of Action

Telotristat ethyl is a prodrug hydrolyzed to the active metabolite telotristat (LP-778902), which inhibits tryptophan hydroxylase (TPH), the rate-limiting enzyme in serotonin (5-HT) biosynthesis. NETs overexpress TPH and produce excess serotonin, causing carcinoid syndrome (diarrhea, flushing, bronchoconstriction). By inhibiting peripheral TPH (primarily TPH1 in enterochromaffin cells), telotristat reduces serotonin production and alleviates carcinoid syndrome diarrhea. It does not cross the blood-brain barrier significantly, minimizing effects on central serotonin.

Pharmacokinetics

Prodrug rapidly converted to active metabolite (telotristat). Telotristat Tmax: 0.5-2 hours. Half-life: approximately 5 hours (parent); 11 hours (active metabolite). Protein binding: >99%. Metabolized by carboxylesterases and CYP3A4. Excreted in feces (93%). Food increases exposure.

14. Clinical Studies

Clinical efficacy and safety data supporting the approval are available in the full prescribing information and from the clinical trials listed below.

Pivotal Clinical Trials
Additional Resources
Approved Tumor Types
External Resources