Fexinidazole

12.1 Mechanism of Action Fexinidazole is an antiprotozoal drug [see Microbiology (12.4) ] .

1 INDICATIONS AND USAGE Fexinidazole Tablets are indicated for the treatment of both the first-stage (hemolymphatic) and second-stage (meningoencephalitic) human African trypanosomiasis (HAT) due to Trypanosoma brucei gambiense in patients 6 years of age and older and weighing at least 20 kg. Fexinidazole Tablets is a nitroimidazole antimicrobial, indicated for the treatment of both first-stage (hemolymphatic) and second-stage (meningoencephalitic) human African trypanosomiasis (HAT) due to Trypanosoma brucei gambiense in patients 6 years of age and older and weighing at least 20 kg. ( 1 ) Limitations of Use Due to the decreased efficacy observed in patients with severe second stage HAT (cerebrospinal fluid white blood cell count (CSF-WBC) >100 cells/µL) due to T. brucei gambiense disease, Fexinidazole Tablets should only be used in these patients if there are no other available treatment options. ( 1 , 5.1 ) Limitations of Use Due to the decreased efficacy observed in patients with severe second stage HAT (cerebrospinal fluid white blood cell count (CSF-WBC) >100 cells/µL) due to T. brucei gambiense disease, Fexinidazole Tablets should only be used in these patients if there are no other available treatment options [see Warnings and Precautions (5.1) ] .

2 DOSAGE AND ADMINISTRATION Administer Fexinidazole Tablets once daily with food each day at about the same time of the day. Do not break or crush tablets. ( 2.1 , 2.2 ) Recommended Dosage of Fexinidazole Tablets in Patients 6 years of age and older and weighing at least 20 kg ( 2.2 ) Body Weight Type of Dose Daily Dose Number of Tablets Duration of Treatment Greater than or equal to 35 kg Loading dose 1,800 mg 3 4 days Maintenance dose 1,200 mg 2 6 days Greater than or equal to 20 kg to less than 35 kg Loading dose 1,200 mg 2 4 days Maintenance dose 600 mg 1 6 days 2.1 Important Administration Instructions Patients should be closely followed by their healthcare provider during treatment with Fexinidazole Tablets. Fexinidazole Tablets must be administered with food [see Dosage and Administration (2.2) ] . Avoid consumption of alcoholic beverages during treatment with Fexinidazole Tablets and for at least 48 hours after completing therapy [see Warnings and Precautions (5.6) ] . If a first event of vomiting occurs after receiving Fexinidazole Tablets, do not re-dose . Administer the next dose the following day using the recommended treatment schedule [see Adverse Reactions (6.1) ] . If a scheduled dose is missed (not taken on the assigned day), normal dosing should resume the following day until the full course (10 days) of treatment has been completed . The clinical consequences of multiple missed doses of Fexinidazole Tablets are not known . 2.2 Recommended Dosage Administer Fexinidazole Tablets, orally, once daily for a total of 10 days (loading dose plus maintenance dose) with food each day at about the same time of the day. Do not break or crush Fexinidazole Tablets. The recommended dosage of Fexinidazole Tablets for patients 6 years of age and older is according to body weight as described in Table 1 below. Table 1: Recommended Dosage of Fexinidazole Tablets in Patients 6 Years of Age and Older and Weighing at Least 20 kg Body weight Type of Dose Recommended Administer Fexinidazole Tablets once daily with food each day at about the same time of the day Daily Dose Number of 600 mg Fexinidazole Tablets Daily Duration of Treatment Greater than or equal to 35 kg Loading dose 1,800 mg 3 4 days Maintenance dose 1,200 mg 2 6 days Greater than or equal to 20 kg to less than 35 kg Loading dose 1,200 mg 2 4 days Maintenance dose 600 mg 1 6 days

6 ADVERSE REACTIONS The following serious and otherwise important adverse reactions are discussed in greater detail in other sections of labeling: Decreased Efficacy in Severe Human African Trypanosomiasis Caused by Trypanosoma brucei gambiense [see Warnings and Precautions (5.1) ] QT Interval Prolongation [see Warnings and Precautions (5.2) ] Neuropsychiatric Adverse Reactions [see Warnings and Precautions (5.3) ] Neutropenia [see Warnings and Precautions (5.4) ] Potential for Hepatotoxicity [see Warnings and Precautions (5.5) ] Most common adverse reactions (incidence >10%) are headache, vomiting, insomnia, nausea, asthenia, tremor, decreased appetite, dizziness, hypocalcemia, dyspepsia, back pain, upper abdominal pain, and hyperkalemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact sanofi-aventis U.S. LLC at 1-800-633-1610 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. Fexinidazole Tablets were evaluated for the treatment of HAT due to T. brucei gambiense in three clinical trials, of which one was comparative and two were noncomparative. Trial 1 compared the safety of Fexinidazole Tablets to nifurtimox-eflornithine combination therapy (NECT) in second stage, meningoencephalitic HAT (N=394). Trial 2 enrolled patients with stage 1 hemolymphatic and early stage 2 HAT (N=230), and Trial 3 assessed the safety of fexinidazole in pediatric patients aged 6 years or older with any stage HAT (N=125). The three trials were primarily conducted in the Democratic Republic of Congo (DRC) and a total of 749 patients received at least one dose of study medication. The patients ranged from 6 to 73 years of age, and 11 were more than 65 years old. Trials 1 and 3 enrolled more males than females (61% and 54% were males, respectively), while the gender distribution was equally balanced in Trial 2. The mean BMI ranged from 16.1 to 19.3 kg/m 2 across trials which was consistent with the nutritional status of the study population. Patients with AST/ALT >2 times the upper limit of normal or total bilirubin >1.5 the upper limit of normal were excluded from the trials. Trial 1 included 264 patients in the fexinidazole treatment arm and 130 patients in the NECT treatment arm. The patients were followed for up to 24 months from the completion of treatment. Common Adverse Reactions The most common adverse reactions occurring in >10% of HAT patients (15 years of age and older) receiving Fexinidazole Tablets in Trial 1 were headache, vomiting, insomnia, nausea, asthenia, tremor, decreased appetite, dizziness, hypocalcemia, dyspepsia, back pain, upper abdominal pain, and hyperkalemia. Selected adverse reactions occurring in ≥2% of HAT patients 15 years of age and older receiving Fexinidazole Tablets in Trial 1 are provided in Table 2. Table 2: Selected Adverse Reactions Occurring in ≥2% of HAT Patients 15 Years of Age and Older Receiving Fexinidazole Tablets in Trial 1 Adverse Reaction Fexinidazole Tablets N=264 N (%) NECT N=130 N (%) Blood and lymphatic system disorders Neutropenia Defined as an absolute neutrophil count of less than 1,000 cells/mm 3 occurring at any time following the first dose of study drug to the end of the study. 15 (5.7%) 4 (3.1%) Cardiac disorders Palpitations 13 (4.9%) 5 (3.8%) Eye disorders Photophobia 6 (2.3%) 0 Gastrointestinal disorders Vomiting 75 (28.4%) 37 (28.4%) Nausea 68 (25.8%) 20 (15.4%) Dyspepsia 34 (12.9%) 10 (7.7%) Abdominal pain upper 27 (10.2%) 6 (4.6%) Salivary hypersecretion 16 (6.1%) 3 (2.3%) Constipation 13 (4.9%) 2 (1.5%) Abdominal distension 8 (3.0%) 0 Gastritis 8 (3.0%) 2 (1.5%) General disorders and administration site conditions Asthenia 60 (22.7%) 19 (14.6%) Feeling hot 25 (9.5%) 3 (2.3%) Chest pain 23 (8.7%) 5 (3.8%) Gait disturbance 12 (4.5%) 2 (1.5%) Metabolism and nutrition disorders Decreased appetite 56 (21.2%) 24 (18.5%) Hypocalcemia 36 (13.6%) 3 (2.3%) Hypoalbuminemia 23 (8.7%) 4 (3.1%) Musculoskeletal and connective tissue disorders Back pain 30 (11.4%) 12 (9.2%) Neck pain 23 (8.7%) 7 (5.4%) Muscle Spasms 7 (2.7%) 1 (0.8%) Nervous system disorders Headache 92 (34.8%) 32 (24.6%) Tremor 58 (22.0%) 15 (11.5%) Dizziness 50 (18.9%) 18 (13.8%) Extrapyramidal disorder 9 (3.4%) 2 (1.5%) Paresthesia 6 (2.3%) 0 Psychiatric disorders Insomnia 74 (28.0%) 15 (11.5%) Agitation 10 (3.8%) 1 (0.8%) Anxiety 10 (3.8%) 0 Abnormal behavior 7 (2.7%) 1 (0.8%) Respiratory, thoracic and mediastinal disorders Cough 16 (6.0%) 6 (4.6%) Dyspnea 6 (2.3%) 1 (0.8%) Skin and subcutaneous tissue disorders Pruritus 10 (3.8%) 4 (3.1%) Hyperhidrosis 7 (2.7%) 2 (1.5%) Vascular disorders Hot flush 13 (4.9%) 4 (3.1%) Hypertension 12 (4.5%) 1 (0.8%) Other Adverse Reactions with Fexinidazole Tablets Occurring in Tri

7 DRUG INTERACTIONS Avoid use of herbal medicines and supplements. ( 7.1 ) See full prescribing information for complete list of clinically significant drug interactions. ( 7.2 ) 7.1 Pharmacodynamic Interactions Herbal Medicines and Supplements There is a potential for pharmacodynamic interactions and/or toxicities between fexinidazole and herbal medicines and supplements. Avoid concomitant use of herbal medicines and supplements during treatment with Fexinidazole Tablets. Drugs that May Prolong the QT Interval and/or Induce Bradycardia Coadministration of Fexinidazole Tablets with drugs known to block potassium channels (e.g., antiarrhythmics, neuroleptics, fluoroquinolones, imidazole and triazole antifungals, pentamidine) prolong the QT interval (e.g., antimalarials, phenothiazines, tricyclic antidepressants, terfenadine and astemizole, IV erythromycin, and quinolone antibacterial drugs) and/or induce bradycardia (such as β-blockers) should be avoided [see Warnings and Precautions (5.2) ] . 7.2 Pharmacokinetic Drug Interactions Table 3: Effect of Fexinidazole on other Drugs Drugs Metabolized by Cytochrome P450 (CYP) 3A4/5 Examples (not fully inclusive): Lovastatin, simvastatin, nisoldipine, saquinavir, midazolam, certain hormonal contraceptives (e.g., birth control pills, skin patches, implant) Clinical Impact Fexinidazole is considered a moderate CYP3A4/5 inducer [see Clinical Pharmacology (12.3) ] . Co-administration of Fexinidazole Tablets and CYP3A4/5 substrates may reduce the systemic exposures of CYP3A4/5 substrate drug(s), which may lead to reduced efficacy [see Clinical Pharmacology (12.3) ] . Prevention or Management Avoid concomitant use with Fexinidazole Tablets . If coadministration cannot be avoided, monitor for lack of efficacy of sensitive substrate drugs. If concomitant use of oral contraceptives cannot be avoided, an alternative contraceptive that is not affected by enzyme inducers (e.g., intrauterine system) or additional nonhormonal contraception (e.g., condoms) is recommended during treatment with Fexinidazole Tablets and for at least 5 days after the last dose. Drugs Metabolized by CYP1A2 or CYP2C19 Examples (not fully inclusive): CYP1A2: duloxetine, tacrine, tizanidine, theophylline CYP2C19: lansoprazole, mephenytoin, diazepam Clinical Impact Increased risk for adverse reactions associated with increased concentrations of the drug due to inhibition of either CYP1A2 or CYP2C19 by fexinidazole [see Clinical Pharmacology (12.3) ] . Prevention or Management Monitor for adverse reactions associated with these drugs when used concomitantly with Fexinidazole Tablets. Drugs Metabolized by CYP2B6 Examples (not fully inclusive): Bupropion, efavirenz Clinical Impact Increased risk for the lack of efficacy associated with decreased plasma concentrations of the drug due to induction of CYP2B6 by fexinidazole and Metabolite M1 [see Clinical Pharmacology (12.3) ] . Prevention or Management Avoid concomitant use with Fexinidazole Tablets. If coadministration cannot be avoided, monitor for lack of efficacy of these drugs. Drugs Metabolized by uridine 5'-diphospho--glucuronosyl transferase (UGT) Examples (not fully inclusive): Zidovudine, bictegravir, cabotegravir, dolutegravir, bexagliflozin, canagliflozin, sotagliflozin, deferasirox, lamotrigine, selexipag Clinical Impact Fexinidazole metabolites have the potential to be UGT inducers [see Clinical Pharmacology (12.3) ] . Co-administration of Fexinidazole Tablets and UGT substrates may reduce the systemic exposures of UGT substrate drug(s), which may lead to reduced efficacy. Prevention or Management When fexinidazole is concomitantly administered with UGT substrates, monitor for lack of efficacy of UGT substrate drugs. Drugs Substrates of OCT2, OAT1, OAT3, MATE1, and MATE2-K Transporters Examples (not fully inclusive): Metformin, dofetilide, adefovir, cefaclor, furosemide Clinical Impact Increased risk for adverse reactions associated with increased concentrations of the drug due to inhibition of these transporters by fexinidazole [see Clinical Pharmacology (12.3) ] . Prevention or Management Avoid concomitant use with Fexinidazole Tablets. If coadministration cannot be avoided, monitor for adverse reactions associated with these drugs. Table 4: Effect of other Drugs on Fexinidazole CYP450 Inducers Examples (not fully inclusive): Rifampin, phenytoin, St. John's wort, carbamazepine Clinical Impact Increased risk for adverse reactions associated with increased systemic exposure to the M1 and M2 metabolites of fexinidazole. M2 plasma concentrations have been associated with the increased risk of QT interval prolongation. Prevention or Management Avoid concomitant use with Fexinidazole Tablets [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3) ]. CYP450 Inhibitors Examples (not fully inclusive): Clarithromycin, itraconazole, voriconazole, erythromycin, fluconazole Clinical Impact Multiple CYP450 enzymes are involved in the metabolism o