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)].

2.1 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.

5.1 Decreased Efficacy in Severe Human African Trypanosomiasis Caused by Trypanosoma brucei gambiense

Decreased efficacy was observed in patients treated with Fexinidazole Tablets as compared to nifurtimox-eflornithine combination therapy (NECT)-treated patients in a randomized, comparative open-label study in the subgroup of patients with severe second stage disease, as defined by cerebrospinal fluid white blood cell count (CSF-WBC) >100 cells/µL at baseline [see Clinical Studies (14)]. The 18-month success rate in this subgroup of patients with severe second stage disease was 86.9% with Fexinidazole Tablets compared to 98.7% with NECT with a difference of -11.8%, 95% confidence interval (CI) (-18.3%, -2.1%). All-cause mortality was higher in patients with severe disease treated with Fexinidazole Tablets than in patients treated with NECT through 24 months (7/160 [4.4%] vs 0/78 [0%], treatment difference 4.4%, 95% CI [-0.9%, 8.9%]).

Patients with severe second stage HAT (CSF-WBC >100 cells/µL) due to T. brucei gambiense disease should only be treated with Fexinidazole Tablets if there are no other available treatment options.

5.2 QT Interval Prolongation

Fexinidazole Tablets have been shown to prolong the QT interval in a concentration-dependent manner [see Clinical Pharmacology (12.2)]. Treatment with Fexinidazole Tablets caused an average increase of 19 msec in the QTcF interval. In clinical trials in HAT patients, three (<1%) patients in the fexinidazole group had a QTcF value of >500 ms versus none in the nifurtimox-eflornithine combination therapy (NECT) group.

Avoid use of Fexinidazole Tablets in patients who have:

• QTcF interval greater than 470 msec
• A history of torsade de pointes, congenital long QT syndrome, cardiac arrhythmias, uncompensated heart failure, or family history of sudden death
• Uncorrected hypokalemia

Avoid concomitant administration of Fexinidazole Tablets with other drugs that are known to prolong the QT interval, those that block cardiac potassium channels, and/or those that induce bradycardia [see Drug Interactions (7.1)].

Avoid concomitant administration of Fexinidazole Tablets with drugs that are inducers of hepatic CYP450 as these drugs may significantly increase plasma concentrations of fexinidazole's active metabolites: fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2). M2 plasma concentrations have been associated with increased QT prolongation risks [see Drug Interactions (7.2)].

If patients are, or need to be, treated with drugs known to prolong QTcF interval or to induce bradycardia either do not initiate therapy with Fexinidazole Tablets until such drugs are eliminated from the body (allow a washout period of 5 half-lives for such other drugs), or do not start such drugs until fexinidazole is eliminated from the body (allow a washout period of 7 days for Fexinidazole Tablets).

5.3 Neuropsychiatric Adverse Reactions

Adult patients treated with Fexinidazole Tablets reported a higher percentage of Central Nervous System (CNS) and psychiatric-related adverse reactions than those treated with nifurtimox eflornithine combination therapy (NECT) in a clinical trial [see Adverse Reactions (6.1)]. Increased incidence in insomnia, headache, and tremor was noted in the patients treated with Fexinidazole Tablets compared to NECT. In the same trial, adverse reactions representing mood changes and psychiatric disorders (such as agitation, anxiety, abnormal behavior, depression, nightmares, hallucination, and personality change) were more common in the patients treated with Fexinidazole Tablets compared to the NECT arm. Suicidal ideation has also been observed with Fexinidazole Tablets [see Adverse Reactions (6.1)]. Healthcare providers should inform patients and their caregivers of the risk for neuropsychiatric adverse reactions during treatment with Fexinidazole Tablets. In patients with current or a history of psychiatric disorders, or should such adverse reactions occur, healthcare providers should consider alternative therapy or increased monitoring of the patient, including hospitalization.

5.4 Neutropenia

Neutropenia (absolute neutrophil count less than 1,000 cells/mm3) has been reported in patients receiving Fexinidazole Tablets [see Adverse Reactions (6.1)]. In Trial 1, the adverse reaction occurred in patients with a baseline absolute neutrophil count of less than 5,000 cells/mm3. Avoid concomitant use of drugs which may cause neutropenia and monitor leukocyte count periodically. Carefully monitor patients with neutropenia for fever or other symptoms or signs of infection and treat promptly if such symptoms or signs occur.

5.5 Potential for Hepatotoxicity

Elevations in liver transaminases occurred in less than two percent of patients receiving Fexinidazole Tablets for the treatment of HAT [see Adverse reactions (6.1) and Overdosage (10)]. Evaluate liver-related laboratory tests at the start [see Contraindications (4)] and during treatment with Fexinidazole Tablets. Monitor patients who develop abnormal liver-related laboratory tests during treatment with Fexinidazole Tablets.

5.6 Risk of Disulfiram-like Reaction Due to Concomitant Use with Alcohol

Nitroimidazole-class drugs may cause a disulfiram-like reaction characterized by flushing, rash, weakness, abdominal cramps, nausea, vomiting and headache in patients who concurrently consume alcohol. Advise patients to avoid consumption of alcohol during treatment with Fexinidazole Tablets and for at least 48 hours after completing therapy [see Dosage and Administration (2.1)].

5.7 Risk of Psychotic Reactions Due to Concomitant Use with Disulfiram

Psychotic reactions have been reported in patients who were concurrently taking disulfiram and nitroimidazole drugs. Avoid use of Fexinidazole Tablets in patients who have taken disulfiram within the last two weeks.

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/m2 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.

6.2 Postmarketing Experience

The following adverse reaction has been identified and reported during post-approval use of other nitroimidazole agents. Because the reports of this reaction are voluntary and the population is of uncertain size, it is not always possible to reliably estimate the frequency of the reaction or establish a causal relationship to drug exposure.

Metronidazole, Another Nitroimidazole Product, Structurally Related to Fexinidazole: Cases of severe irreversible hepatotoxicity/acute liver failure, including cases with fatal outcomes with very rapid onset after initiation of systemic use of metronidazole, another nitroimidazole agent structurally related to fexinidazole, have been reported in patients with Cockayne syndrome (latency from drug start to signs of liver failure as short as 2 days) [see Contraindications (4)].

7.1 Pharmacodynamic Interactions

7.2 Pharmacokinetic Drug Interactions

8.1 Pregnancy

8.2 Lactation

8.4 Pediatric Use

The safety and effectiveness of Fexinidazole Tablets for the treatment of both the first-stage (hemolymphatic) and second-stage (meningoencephalitic) HAT due to Trypanosoma brucei gambiense have been established in pediatric patients aged 6 years and older and weighing at least 20 kg. Use of Fexinidazole Tablets for this indication is supported by evidence from an adequate and well-controlled trial in adults with additional efficacy, pharmacokinetic and safety data in pediatric patients aged 6 years and older [see Adverse Reactions (6.1), Clinical Pharmacology (12.3), and Clinical Studies (14)].

Pediatric patients may be more sensitive to vomiting. The safety profile for Fexinidazole Tablets in pediatric patients was generally similar to that of adult patients with the exception of more frequent vomiting within 2 hours of administration of Fexinidazole Tablets. Vomiting did not result in permanent treatment discontinuation [see Adverse Reactions (6.1)].

The safety and efficacy of Fexinidazole Tablets have not been established in pediatric patients younger than 6 years old and/or less than 20 kg in body weight.

8.5 Geriatric Use

Of the 619 subjects in the three clinical trials treated with Fexinidazole Tablets for HAT, there were 11 subjects who were 65 years of age or older, and no subjects greater than 75 years of age. There were an insufficient number of elderly subjects to detect differences in safety and/or effectiveness between elderly and younger adult patients.

8.6 Renal Impairment

No dosage adjustment is needed for patients with mild to moderate renal impairment with estimated glomerular filtration rates (eGFR) from 30 mL/min/1.73 m2 to less than or equal to 89 mL/min/1.73 m2 [see Clinical Pharmacology (12.3)]. The pharmacokinetics of fexinidazole in patients with severe renal impairment (eGFR less than 30 mL/min/1.73 m2) is unknown. Avoid the use of Fexinidazole Tablets in patients with severe renal impairment.

8.7 Hepatic Impairment

No dosage adjustment of Fexinidazole Tablets is recommended for patients with mild hepatic impairment (Child-Pugh Class A). Moderate hepatic impairment (Child-Pugh Class B) increases fexinidazole and its active metabolite M1 exposures, which may increase the risk of adverse reactions [see Clinical Pharmacology (12.3)]. Use of Fexinidazole Tablets is contraindicated in patients with severe hepatic impairment [see Contraindications (4) and Warnings and Precautions (5.5)].

12.1 Mechanism of Action

Fexinidazole is an antiprotozoal drug [see Microbiology (12.4)].

12.2 Pharmacodynamics

12.3 Pharmacokinetics

The pharmacokinetics (PK) of fexinidazole and its two pharmacologically active M1 (sulfoxide) and M2 (sulfone) metabolites following administration of the recommended adult dosage regimen of Fexinidazole Tablets in 12 healthy adult male subjects under fed conditions are presented in Table 5.

12.4 Microbiology

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Trial 1

The efficacy and safety of Fexinidazole Tablets were evaluated in a randomized, comparative open-label trial (Trial 1, NCT01685827) conducted in adult patients with late second-stage HAT due to T. brucei gambiense. Patients had evidence of parasites in blood, lymph and/or cerebrospinal fluid (CSF) at trial enrollment. If testing for parasites in CSF was negative, a CSF WBC >20 cells/μL was required to confirm late second-stage HAT. Patients (n=394) were randomized in a 2:1 ratio to a 10-day treatment regimen of either Fexinidazole Tablets (n=264) or nifurtimox-eflornithine combination therapy (NECT) (n=130). The mean age was 35 years (range 15 to 71) and 61% were male. The fexinidazole tablet group received 1,800 mg of Fexinidazole Tablets orally once daily on Days 1 through 4, followed by 1,200 mg orally once daily on Days 5 through 10, with all dosing in the fed state. The NECT control arm received nifurtimox tablets 15 mg/kg/day in three divided doses for 10 days as well as eflornithine injectable solution 400 mg/kg/day in two divided doses for 7 days. Patients were hospitalized throughout their treatment and were allowed to leave the hospital from Day 13 onwards if their clinical status was satisfactory. Patients were followed up at 3, 6, 12, 18, and 24 months after the end of treatment visit. HAT symptoms reported at baseline in >50% of patients included headache, pruritus, sleepiness, weight loss, and asthenia. The median CSF WBC count was 157 cells/µL.

The outcome at 18 months was considered a success if patients were classified as a cure or probable cure as defined below:

• Cure: Patient is alive with no evidence of trypanosomes in any body fluid and CSF WBC ≤20 cells/µL.
• Probable cure for patients who refused a lumbar puncture (or who had a hemorrhagic CSF sample) at 18 months: No parasites in the blood or lymph and a satisfactory clinical condition without clinical signs or symptoms (or clinical status is unlikely to be due to HAT), CSF WBC <50 cells/µL at 6 and/or 12 months and not increasing at 12 months, as long as there was no indication of a relapse up to 24 months and no definitive failure (presence of trypanosomes) had been observed before in any body fluid.

Success rates at 18 months are shown in Table 6 for the modified intention-to-treat (mITT) population, which consisted of all randomized patients who received at least one dose of study treatment but excluded 5 randomized patients due to geopolitical unrest. The success rate in the fexinidazole treatment arm was lower than in the NECT arm. Additionally, more deaths occurred in the fexinidazole treatment arm at 24 months (n=9, 3.4%) compared to the NECT treatment arm (n=2, 1.6%). This decreased efficacy and increased mortality was noted in the subgroup of patients who had CSF-WBC >100 cells/µL at baseline [see Warnings and Precautions (5.1)]. The results at 24 months were consistent with the results at 18 months with 24-month success rates of 89.7% (235/262) in the fexinidazole treatment arm and 97.6% (124/127) in the NECT arm.

Trial 2 and Trial 3

Additional supportive evidence for efficacy in early stage HAT due to T. brucei gambiense, and in pediatric patients was obtained from two single-arm trials: a single-arm trial in adults (Trial 2, NCT02169557), and a single-arm trial in pediatric patients aged 6 to 15 years old and weighing at least 20 kg (Trial 3, NCT02184689). In Trial 2, the mean age of patients was 34 years and 82% of patients had evidence of first-stage HAT (evidence of trypanosomes in the blood or lymph, no trypanosomes in the CSF, and CSF WBC ≤5 cells /µL). In Trial 3, the mean age of patients was 11 years and 55% of patients had evidence of first-stage HAT. Fexinidazole Tablets 1,200 mg, was given in fed condition once a day on Days 1 through 4, followed by 600 mg on Days 5 through 10 to patients weighing <35 kg, and all other patients received the adult dosing regimen. Treatment success proportions in all patients with first- or late-stage HAT were 98.7% (227/230, 95% CI [96.2%, 99.7%]) at 12 months in Trial 2 and 97.6% (122/125, 95% CI [93.1%, 99.5%]) at 12 months in Trial 3. The results at 18 months were consistent with the results at 12 months.

Store below 30°C (86°F). Store in the original package in order to protect from light and moisture.

Administration with Food

Advise the patient that Fexinidazole Tablets must be taken with food each day at about the same time of the day (e.g., during or immediately after the main meal of the day), to make sure it is adequately absorbed [see Dosage and Administration (2.1, 2.2)].

Alcohol Consumption

Advise patients not to consume alcoholic beverages during treatment with Fexinidazole Tablets and for at least 48 hours after completing Fexinidazole Tablets therapy [see Dosage and Administration (2.1) and Warnings and Precautions (5.6)].

Vomiting

Advise the patient not to administer an additional dose if vomiting occurs after the administration of Fexinidazole Tablets but continue with the next scheduled dose the following day. If a second event of vomiting occurs after administration of any other dose of Fexinidazole Tablets, counsel the patient on the importance of contacting the healthcare provider immediately [see Dosage and Administration (2.1)].

Missed Doses

Advise patients that 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. Counsel the patient on the importance of contacting the health care practitioner immediately if a second scheduled dose is missed [see Dosage and Administration (2.1)].

Neuropsychiatric Adverse Reactions

Counsel patients and their caregivers of the risk for neuropsychiatric adverse reactions, such as insomnia, headache, tremor, mood changes, psychiatric disorders (such as agitation, anxiety, abnormal behavior, depression, nightmares, hallucination, and personality change) and suicidal ideation [see Warnings and Precautions (5.3) and Adverse Reactions (6.1)]. If such adverse reactions occur, advise the patients and their caregivers to contact their healthcare provider immediately.

Dizziness

Counsel the patient that they should not drive or use machines if they feel tired or dizzy. Dizziness, fatigue, asthenia, and somnolence have been reported following treatment with Fexinidazole Tablets [see Adverse Reactions (6.1)].

Drug Interactions

Advise patients to disclose to their healthcare provider all other medications, including herbal medicines, the patient is currently taking while being treated with fexinidazole tablets [see Drug Interactions (7)].