Xermelo

telotristat ethyl · Tablet · Oral

Prescription (Rx) Tryptophan Hydroxylase Inhibitor

Uses

Xermelo is indicated for the treatment of carcinoid syndrome diarrhea in combination with somatostatin analog (SSA) therapy in adults inadequately controlled by SSA therapy. Xermelo is a tryptophan hydroxylase inhibitor indicated for the treatment of carcinoid syndrome diarrhea in combination with somatostatin analog (SSA) therapy in adults inadequately controlled by SSA therapy. ( 1 )

Dosage and administration

The recommended dosage of Xermelo in adult patients is 250 mg three times daily for patients whose diarrhea is inadequately controlled by SSA therapy. Administration Take Xermelo with food [see Clinical Pharmacology ( 12.3 ), Clinical Studies ( 14 )] . When short-acting octreotide is used in combination with Xermelo, administer short-acting octreotide at least 30 minutes after administering Xermelo [see Drug Interactions ( 7.3 )] . If a dose is missed, take the next dose at the regular time. Do not take 2 doses at the same time to make up for a missed dose. Discontinue Xermelo if severe constipation develops [see Warnings and Precautions ( 5.1 )]. The recommended dosage of Xermelo in adult patients is 250 mg three times daily for patients whose diarrhea is inadequately controlled by a SSA therapy. ( 2 ) Take Xermelo with food. ( 2 ) When short-acting octreotide is used in combination with Xermelo, administer short-acting octreotide at least 30 minutes after administering Xermelo. ( 2 , 7.3 ) Discontinue Xermelo if severe constipation develops. ( 2 , 5.1 )

Dosage forms and strengths

Tablets: 250 mg telotristat ethyl; white to off-white, coated and oval with “T-E” debossed on one side and “250” debossed on the other side. Tablets: 250 mg telotristat ethyl ( 3 )

Contraindications

Xermelo is contraindicated in patients with a history of a hypersensitivity reaction to telotristat. Reactions have included angioedema, rash and pruritus. History of hypersensitivity to telotristat. ( 4 )

Warnings and precautions

Constipation: Xermelo reduces bowel movement frequency; monitor patients for constipation, and/or severe persistent or worsening abdominal pain. Discontinue Xermelo if constipation or abdominal pain develops. ( 5.1 ) 5.1 Constipation Xermelo reduces bowel movement frequency and may lead to constipation. Serious complications of constipation have been reported during clinical trials and postmarketing. In a 12-week, placebo-controlled trial, in which patients had 4 or greater bowel movements per day, 2 out of 45 patients treated with a higher than recommended dosage of Xermelo reported constipation. In one patient the constipation was serious, resulting in hospitalization. During the 36-week extension period with higher than the recommended dosage of Xermelo, 10 of 115 patients reported constipation, with individual reports of intestinal perforation, obstruction, and fecaloma. In another 12-week, placebo-controlled trial in which patients had less than 4 bowel movements per day, 4 out of 25 patients treated with the recommended dosage of Xermelo reported constipation. Serious complications of constipation in patients treated with Xermelo at the recommended dosage (e.g., intestinal obstruction) have also been reported in the postmarket setting. Most patients had additional risk factors, including underlying disease and concomitant constipating medications. Given that patients with metastatic carcinoid tumors may have impaired integrity of the gastrointestinal tract wall, monitor for the development of constipation and/or severe, persistent, or worsening abdominal pain in patients taking Xermelo. Discontinue Xermelo if severe constipation or severe persistent or worsening abdominal pain develops [see Dosage and Administration ( 2 ), Adverse Reactions ( 6.1 )] .

Side effects

Most common adverse reactions (≥5%) are nausea, headache, increased GGT, depression, flatulence, decreased appetite, peripheral edema, and pyrexia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact TerSera Therapeutics LLC at 1-844-334-4035 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Xermelo was studied in a double-blind, placebo-controlled clinical trial of 90 patients with metastatic neuroendocrine tumors and carcinoid syndrome diarrhea. Patients reported between 4 to 12 bowel movements daily despite the use of SSA therapy at a stable dose for at least 3 months [see Clinical Studies ( 14 )] . Placebo or Xermelo 250 mg was administered three times daily for 12 weeks. Concomitant anti-diarrheal medications (e.g., loperamide) were used by 43% (36% and 51% in the placebo and Xermelo group, respectively), pancreatic enzyme replacement medications by 39% (36% and 42% in the placebo and Xermelo group, respectively), and opioid analgesics by 29% (24% and 33% in the placebo and Xermelo group, respectively) of patients during the 12-week double-blind period of the trial. Table 1 below lists adverse reactions occurring at an incidence of at least 5% in the Xermelo group (N=45) and at an incidence greater than placebo (N=45) during the 12-week placebo-controlled period of the trial. Table 1: Percent Common Adverse Reactions a by Treatment Group at 12-Weeks in a Double-Blind Placebo-Controlled Clinical Trial of Patients with Carcinoid Syndrome Diarrhea a incidence of at least 5% in the Xermelo group and at an incidence greater than placebo b including depression, depressed mood and decreased interest Adverse Reaction Xermelo 250 mg Three Times Daily, N=45 (%) Placebo, N=45 (%) Nausea 13 11 Headache 11 4 Increased gamma-glutamyl-transferase (GGT) 9 0 Depression b 9 7 Peripheral edema 7 2 Flatulence 7 2 Decreased appetite 7 4 Pyrexia 7 4 In another placebo-controlled clinical trial of patients with carcinoid syndrome diarrhea and less than 4 bowel movements per day, the following additional adverse reactions, not listed in Table 1 , of abdominal pain (including upper and lower abdominal pain, abdominal distention and gastrointestinal pain) and constipation were reported in at least 5% of patients in the Xermelo treated group and at an incidence greater than placebo [see Warnings and Precautions ( 5.1 )] . Less Common Adverse Reactions : The following is a list of adverse reactions occurring in less than 5% of patients receiving Xermelo during the 12-week placebo-controlled period of the clinical trial: Investigations : increased alkaline phosphatase, increased alanine aminotransferase, and increased aspartate aminotransferase. Fecaloma was reported in one patient treated with Xermelo (at a higher than recommended dosage) during the 36-week open-label extension period following the 12-week double-blind period of the trial. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of Xermelo. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Gastrointestinal: intestinal obstruction [see Warnings and Precautions ( 5.1 )] Immune system disorders: angioedema Skin and subcutaneous tissue disorders: pruritus, rash

Drug interactions

7 DRUG INTERACTIONS CYP3A4 Substrates (e.g., midazolam) and CYP2B6 Substrates (e.g., bupropion, efavirenz): Efficacy of concomitant drugs may be decreased; monitor patients’ response and consider increasing the dosage of the concomitant drug, if necessary. ( 7.1 ) 7.1 CYP3A4 Substrates Concomitant use of Xermelo may decrease the efficacy of drugs that are CYP3A4 substrates (e.g., midazolam) by decreasing their systemic exposure. Monitor patients’ response to CYP3A4 substrates when co-administered with Xermelo and consider increasing the dosage of the interacting drug, if necessary [see Clinical Pharmacology ( 12.3 )] . 7.2 CYP2B6 Substrates Concomitant use of Xermelo may decrease the efficacy of drugs that are CYP2B6 substrates (e.g., bupropion, efavirenz) by decreasing their systemic exposure. Monitor patients’ response to CYP2B6 substrates when co-administered with Xermelo and consider increasing the dosage of the interacting drug, if necessary [see Clinical Pharmacology ( 12.3 )] . 7.3 Short-Acting Octreotide Concurrent administration of short-acting octreotide with Xermelo significantly decreased the systemic exposure of telotristat ethyl and telotristat, the active metabolite. If treatment with short-acting octreotide is needed in combination with Xermelo, administer short-acting octreotide at least 30 minutes after administration of Xermelo [see Clinical Pharmacology ( 12.3 )] .

Use in specific populations

8.1 Pregnancy Risk Summary There are no human data with Xermelo use in pregnant women to inform a drug-associated risk. In animal reproduction studies, no effects on embryo-fetal development were observed with the administration of oral telotristat ethyl to rats during organogenesis at doses up to 750 mg/kg/day (approximately 9 times the exposure at the RHD [recommended human dose]). Treatment of pregnant rabbits with oral telotristat ethyl during organogenesis produced maternal toxicity and post-implantation loss at doses of 250 mg/kg/day or higher (approximately 15 times the exposure at the RHD), and reduced fetal weight at 500 mg/kg/day (approximately 33 times the exposure at the RHD). In a pre-/postnatal development study, an increased incidence of mortality in rat offspring was observed during postnatal days 0 to 4 at the maternal oral dose of 500 mg/kg/day (approximately 5 times the exposure at the RHD), given during organogenesis through lactation (see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal data An embryo-fetal development study performed in rats with oral telotristat ethyl at doses up to 750 mg/kg/day (approximately 9 times the AUC [area under the plasma concentration-time curve] for the active metabolite at the RHD) during organogenesis produced no harm to embryo-fetal development. In pregnant rabbits treated orally with telotristat ethyl during organogenesis, an increased incidence of post-implantation loss at doses of 250 and 500 mg/kg/day (approximately 15 times the AUC for the active metabolite at RHD) and a decrease in fetal weight at 500 mg/kg/day (approximately 33 times the AUC for the active metabolite at the RHD) was observed. The adverse effects on embryo-fetal development were associated with maternal toxicity (impaired weight gain and/or mortality) at 250 and 500 mg/kg/day. No adverse effects on embryo-fetal development were observed at 125 mg/kg/day (approximately 5 times the AUC for the active metabolite at the RHD). A pre-/postnatal development study was conducted in rats using oral administration of 100, 200, and 500 mg/kg/day telotristat ethyl during organogenesis through lactation. An increased incidence of pup mortality was observed during postnatal days 0 to 4 at the maternal dose of 500 mg/kg/day (approximately 5 times the AUC for the active metabolite at the RHD). No developmental abnormalities or effects on growth, learning and memory, or reproductive performance were observed through maturation of offspring at maternal doses of up to 500 mg/kg/day in surviving offspring. 8.2 Lactation Risk Summary There are no data on the presence of telotristat ethyl in human or animal milk, the effects on the breastfed infant, or the effects on milk production. The effects of local gastrointestinal and systemic exposure to telotristat ethyl on breastfed infants are unknown. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Xermelo and any potential adverse effects on the breastfed infant from Xermelo or from the underlying maternal condition. Clinical Considerations Monitor the breastfed infant for symptoms of constipation. 8.4 Pediatric Use The safety and effectiveness of Xermelo in pediatric patients have not been established. 8.5 Geriatric Use Of 45 patients in a clinical trial of Xermelo, 19 (42%) patients were 65 years of age and over. No overall differences in safety or effectiveness were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. 8.6 Renal Impairment No dosage adjustment of Xermelo is necessary in patients with mild, moderate or severe renal impairment who are not requiring dialysis. There is no information on Xermelo in patients with end-stage renal disease who require dialysis (eGFR <15 mL/min/1.73 m 2 ). 8.7 Hepatic Impairment Systemic exposure of telotristat ethyl and its active metabolite, telotristat, were substantially increased in patients with moderate hepatic impairment (Child-Pugh Class B) and severe hepatic impairment (Child-Pugh C) (3.2- and 5.0-fold, respectively) compared to patients with normal hepatic function [see Clinical Pharmacology ( 12.3 )] . Xermelo is not recommended in patients with moderate and severe hepatic impairment. No dosage adjustment of Xermelo is necessary in patients with mild hepatic impairment (Child-Pugh A); however, additional monitoring of Xermelo-associated adverse reactions (e.g., constipation) is recommended in these patients [see Warnings and Precautions ( 5.1 )] .

Pregnancy

8.1 Pregnancy Risk Summary There are no human data with Xermelo use in pregnant women to inform a drug-associated risk. In animal reproduction studies, no effects on embryo-fetal development were observed with the administration of oral telotristat ethyl to rats during organogenesis at doses up to 750 mg/kg/day (approximately 9 times the exposure at the RHD [recommended human dose]). Treatment of pregnant rabbits with oral telotristat ethyl during organogenesis produced maternal toxicity and post-implantation loss at doses of 250 mg/kg/day or higher (approximately 15 times the exposure at the RHD), and reduced fetal weight at 500 mg/kg/day (approximately 33 times the exposure at the RHD). In a pre-/postnatal development study, an increased incidence of mortality in rat offspring was observed during postnatal days 0 to 4 at the maternal oral dose of 500 mg/kg/day (approximately 5 times the exposure at the RHD), given during organogenesis through lactation (see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal data An embryo-fetal development study performed in rats with oral telotristat ethyl at doses up to 750 mg/kg/day (approximately 9 times the AUC [area under the plasma concentration-time curve] for the active metabolite at the RHD) during organogenesis produced no harm to embryo-fetal development. In pregnant rabbits treated orally with telotristat ethyl during organogenesis, an increased incidence of post-implantation loss at doses of 250 and 500 mg/kg/day (approximately 15 times the AUC for the active metabolite at RHD) and a decrease in fetal weight at 500 mg/kg/day (approximately 33 times the AUC for the active metabolite at the RHD) was observed. The adverse effects on embryo-fetal development were associated with maternal toxicity (impaired weight gain and/or mortality) at 250 and 500 mg/kg/day. No adverse effects on embryo-fetal development were observed at 125 mg/kg/day (approximately 5 times the AUC for the active metabolite at the RHD). A pre-/postnatal development study was conducted in rats using oral administration of 100, 200, and 500 mg/kg/day telotristat ethyl during organogenesis through lactation. An increased incidence of pup mortality was observed during postnatal days 0 to 4 at the maternal dose of 500 mg/kg/day (approximately 5 times the AUC for the active metabolite at the RHD). No developmental abnormalities or effects on growth, learning and memory, or reproductive performance were observed through maturation of offspring at maternal doses of up to 500 mg/kg/day in surviving offspring.

Pediatric use

8.4 Pediatric Use The safety and effectiveness of Xermelo in pediatric patients have not been established. 8.6 Renal Impairment No dosage adjustment of Xermelo is necessary in patients with mild, moderate or severe renal impairment who are not requiring dialysis. There is no information on Xermelo in patients with end-stage renal disease who require dialysis (eGFR <15 mL/min/1.73 m 2 ). 8.7 Hepatic Impairment Systemic exposure of telotristat ethyl and its active metabolite, telotristat, were substantially increased in patients with moderate hepatic impairment (Child-Pugh Class B) and severe hepatic impairment (Child-Pugh C) (3.2- and 5.0-fold, respectively) compared to patients with normal hepatic function [see Clinical Pharmacology ( 12.3 )] . Xermelo is not recommended in patients with moderate and severe hepatic impairment. No dosage adjustment of Xermelo is necessary in patients with mild hepatic impairment (Child-Pugh A); however, additional monitoring of Xermelo-associated adverse reactions (e.g., constipation) is recommended in these patients [see Warnings and Precautions ( 5.1 )] .

Geriatric use

8.5 Geriatric Use Of 45 patients in a clinical trial of Xermelo, 19 (42%) patients were 65 years of age and over. No overall differences in safety or effectiveness were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

Description

Xermelo (telotristat ethyl) tablets contain telotristat ethyl as telotristat etiprate, a tryptophan hydroxylase inhibitor. Telotristat etiprate is the hippurate salt of telotristat ethyl [(S)-ethyl 2-amino-3-(4-(2-amino-6-((R)-1-(4-chloro-2-(3-methyl-1H-pyrazol-1-yl)phenyl)-2,2,2-trifluoroethoxy)pyrimidin-4-yl)phenyl)propanoate], which undergoes hydrolysis to the active metabolite, (S)-2-amino-3-(4-(2-amino-6-((R)-1-(4-chloro-2-(3-methyl-1H-pyrazol-1-yl)phenyl)-2,2,2-trifluoroethoxy)pyrimidin-4-yl)phenyl)propanoic acid. The molecular formula of telotristat etiprate is C 27 H 26 ClF 3 N 6 O 3
• C 9 H 9 NO 3 and its molecular weight is 754.2. The molecular weight of the free base (telotristat ethyl) is 575.0. Chemical Structure: Telotristat etiprate is a white to off-white solid. The solubility is a function of pH at 25°C; at pH 1 (0.1N HCl), the solubility is greater than 71 mg/mL, at pH 3 phosphate buffer, the solubility is 0.30 mg/mL, at a pH of 5 to 9, the solubility is negligible. In organic solvents, telotristat etiprate is freely soluble in methanol, soluble in acetone, and sparingly soluble in ethanol. Each Xermelo tablet contains 250 mg of telotristat ethyl (free base) which is equivalent to 328 mg telotristat etiprate. The inactive ingredients of Xermelo tablets include: colloidal silicon dioxide, croscarmellose sodium, hydroxypropyl cellulose, lactose anhydrous, macrogol/PEG, magnesium stearate, polyvinyl alcohol [part hydrolyzed], talc and titanium dioxide. Chemical Structure

Mechanism of action

12.1 Mechanism of Action Telotristat, the active metabolite of telotristat ethyl, is an inhibitor of tryptophan hydroxylase, which mediates the rate limiting step in serotonin biosynthesis. The in vitro inhibitory potency of telotristat towards tryptophan hydroxylase is 29 times higher than that of telotristat ethyl. Serotonin plays a role in mediating secretion, motility, inflammation, and sensation of the gastrointestinal tract, and is over-produced in patients with carcinoid syndrome. Through inhibition of tryptophan hydroxylase, telotristat and telotristat ethyl reduce the production of peripheral serotonin, and the frequency of carcinoid syndrome diarrhea.

How supplied

How Supplied 250 mg tablet: white to off-white coated oval tablet with “T-E” debossed on one side and “250” debossed on the other side. Xermelo is dispensed in a monthly case for a total of 28 days of therapy. Each monthly case contains four weekly packs. Each weekly pack contains 21 tablets. NDC 70720-125-85: Monthly case of 84 tablets. Each child resistant weekly pack contains twenty-one 250 mg tablets. Storage Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

Storage

Storage Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].

Patient information

Advise patients: If they experience severe constipation or severe persistent or worsening abdominal pain, to discontinue Xermelo and contact their healthcare provider [see Warnings and Precautions ( 5.1 )] . To take Xermelo with food [see Clinical Pharmacology ( 12.3 ), Clinical Studies ( 14 )] . When short-acting octreotide is used in combination with Xermelo, administer short-acting octreotide at least 30 minutes after administering Xermelo [see Drug Interactions ( 7.3 )] . If a dose is missed, take the next dose at the regular time. Do not take 2 doses at the same time to make up for a missed dose. Distributed by: TerSera Therapeutics LLC, Deerfield, IL 60015 ©2026 TerSera Therapeutics LLC

Label text from the FDA structured product label by TerSera Therapeutics LLC (revised Aug 6, 2026). Long sections are shortened; the complete label is on DailyMed.

Active ingredients

Xermelo NDC products (2)

NDCStrength & formLabelerType
70183-125Telotristat Ethyl 250 mg/1
Tablet
Lexicon Pharmaceuticals, Inc.NDA
70720-125Telotristat Ethyl 250 mg/1
Tablet
TerSera Therapeutics LLCNDA

Frequently asked questions

What is Xermelo used for?

Xermelo is indicated for the treatment of carcinoid syndrome diarrhea in combination with somatostatin analog (SSA) therapy in adults inadequately controlled by SSA therapy. Xermelo is a tryptophan hydroxylase inhibitor indicated for the treatment of carcinoid syndrome diarrhea in combination with somatostatin analog (SSA) therapy in adults inadequately controlled by SSA therapy. ( 1 )

What are the side effects of Xermelo?

Most common adverse reactions (≥5%) are nausea, headache, increased GGT, depression, flatulence, decreased appetite, peripheral edema, and pyrexia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact TerSera Therapeutics LLC at 1-844-334-4035 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions,… See the full label for the complete list.

Who makes Xermelo?

Xermelo is listed by 2 labelers in the FDA NDC directory, including Lexicon Pharmaceuticals, Inc., TerSera Therapeutics LLC.