Telotristat

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.

1 INDICATIONS AND USAGE 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 )

2 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 )

6 ADVERSE REACTIONS 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: pruritis, rash

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 )] .