Феморикс

Феморикс^® is indicated for the treatment of patients with relapsing forms of multiple sclerosis.

The recommended dose of Феморикс is 7 mg or 14 mg orally once daily. Феморикс can be taken with or without food.

Monitoring To Assess safety

• Obtain transaminase and bilirubin levels within 6 months before initiation of Феморикс therapy. Monitor ALT levels at least monthly for six months after starting Феморикс.
• Obtain a complete blood cell count (CBC) within 6 months before the initiation of treatment with Феморикс. Further monitoring should be based on signs and symptoms of infection.
• Prior to initiating Феморикс, screen patients for latent tuberculosis infection with a tuberculin skin test or blood test for mycobacterium tuberculosis infection.
• Exclude pregnancy prior to initiation of treatment with Феморикс in females of reproductive potential.
• Check blood pressure before start of Феморикс treatment and periodically thereafter.

Феморикс is contraindicated in/with:

• Patients with severe hepatic impairment.
• Pregnant women and females of reproductive potential not using effective contraception. Феморикс may cause fetal harm.
• Patients with a history of a hypersensitivity reaction to teriflunomide, leflunomide, or to any of the inactive ingredients in Феморикс. Reactions have included anaphylaxis, angioedema, and serious skin reactions.
• Coadministration with leflunomide.

WARNINGS

Included as part of the "PRECAUTIONS" Section

PRECAUTIONS

Hepatotoxicity

Severe liver injury including fatal liver failure and dysfunction has been reported in some patients treated with leflunomide, which is indicated for rheumatoid arthritis. A similar risk would be expected for teriflunomide because recommended doses of teriflunomide and leflunomide result in a similar range of plasma concentrations of teriflunomide. Patients with pre-existing liver disease may be at increased risk of developing elevated serum transaminases when taking Феморикс. Patients with pre-existing acute or chronic liver disease, or those with serum alanine aminotransferase (ALT) greater than two times the upper limit of normal (ULN) before initiating treatment, should not normally be treated with Феморикс. Феморикс is contraindicated in patients with severe hepatic impairment.

In placebo-controlled trials, ALT greater than three times the ULN occurred in 61/1045 (5.8%) and 62/1002 (6.2%) of patients receiving Феморикс 7 mg and 14 mg, respectively, and 38/997 (3.8%) of patients receiving placebo, during the treatment period. These elevations occurred mostly within the first year of treatment. Half of the cases returned to normal without drug discontinuation. In clinical trials, if ALT elevation was greater than three times the ULN on two consecutive tests, Феморикс was discontinued and patients underwent an accelerated elimination procedure. Of the patients who underwent discontinuation and accelerated elimination in controlled trials, half returned to normal or near normal values within 2 months.

One patient in the controlled trials developed ALT 32 times the ULN and jaundice 5 months after initiation of Феморикс 14 mg treatment. The patient was hospitalized for 5 weeks and recovered after plasmapheresis and cholestyramine accelerated elimination procedure. Феморикс-induced liver injury in this patient could not be ruled out.

Obtain serum transaminase and bilirubin levels within 6 months before initiation of Феморикс therapy. Monitor ALT levels at least monthly for six months after starting Феморикс. Consider additional monitoring when Феморикс is given with other potentially hepatotoxic drugs.

Consider discontinuing Феморикс if serum transaminase increase (greater than three times the ULN) is confirmed. Monitor serum transaminase and bilirubin on Феморикс therapy, particularly in patients who develop symptoms suggestive of hepatic dysfunction, such as unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, or jaundice and/or dark urine. If liver injury is suspected to be Феморикс-induced, discontinue Феморикс and start an accelerated elimination procedure and monitor liver tests weekly until normalized. If Феморикс-induced liver injury is unlikely because some other probable cause has been found, resumption of Феморикс therapy may be considered.

Teratogenicity

Феморикс may cause fetal harm when administered to a pregnant woman. Teratogenicity and embryo-fetal lethality occurred in animal reproduction studies in multiple animal species at plasma teriflunomide exposures similar to or lower than that in humans at the maximum human recommended dose (MHRD) of 14 mg/day.

Феморикс is contraindicated for use in pregnant women and females of reproductive potential not using effective contraception.

Procedure For Accelerated Elimination Of Teriflunomide

Teriflunomide is eliminated slowly from the plasma. Without an accelerated elimination procedure, it takes on average 8 months to reach plasma concentrations less than 0.02 mg/L, although because of individual variations in drug clearance it may take as long as 2 years. An accelerated elimination procedure could be used at any time after discontinuation of Феморикс. Elimination can be accelerated by either of the following procedures:

• Administration of cholestyramine 8 g every 8 hours for 11 days. If cholestyramine 8 g three times a day is not well tolerated, cholestyramine 4 g three times a day can be used.
• Administration of 50 g oral activated charcoal powder every 12 hours for 11 days.

If either elimination procedure is poorly tolerated, treatment days do not need to be consecutive unless there is a need to lower teriflunomide plasma concentration rapidly.

At the end of 11 days, both regimens successfully accelerated teriflunomide elimination, leading to more than 98% decrease in teriflunomide plasma concentrations.

Use of the accelerated elimination procedure may potentially result in return of disease activity if the patient had been responding to Феморикс treatment.

Bone Marrow Effects/Immunosuppression Potential/Infections

Bone Marrow Effects

A mean decrease compared to baseline in white blood cell (WBC) count of approximately 15% (mainly neutrophils and lymphocytes) and in platelet count of approximately 10% was observed in placebo-controlled trials with 7 mg and 14 mg of Феморикс. The decrease in mean WBC count occurred during the first 6 weeks and WBC count remained low during treatment. In placebo-controlled studies, neutrophil count <1.5 × 10⁹/L was observed in 12% and 16% of patients receiving Феморикс 7 mg and 14 mg, respectively, compared with 7% of patients receiving placebo; lymphocyte count <0.8 × 10⁹/L was observed in 10% and 12% of patients receiving Феморикс 7 mg and 14 mg, respectively, compared with 6% of patients receiving placebo. No cases of serious pancytopenia were reported in premarketing clinical trials of Феморикс but rare cases of pancytopenia and agranulocytosis have been reported in the postmarketing setting with leflunomide. A similar risk would be expected for Феморикс. Cases of thrombocytopenia with Феморикс, including rare cases with platelet counts less than 50,000/mm³, have been reported in the postmarketing setting. Obtain a complete blood cell count (CBC) within 6 months before the initiation of treatment with Феморикс. Further monitoring should be based on signs and symptoms suggestive of bone marrow suppression.

Risk Of Infection/Tuberculosis Screening

Patients with active acute or chronic infections should not start treatment until the infection(s) is resolved. If a patient develops a serious infection consider suspending treatment with Феморикс and using an accelerated elimination procedure. Reassess the benefits and risks prior to resumption of therapy. Instruct patients receiving Феморикс to report symptoms of infections to a physician.

Феморикс is not recommended for patients with severe immunodeficiency, bone marrow disease, or severe, uncontrolled infections. Medications like Феморикс that have immunosuppression potential may cause patients to be more susceptible to infections, including opportunistic infections.

In placebo-controlled studies of Феморикс, no overall increase in the risk of serious infections was observed with Феморикс 7 mg (2.2%) or 14 mg (2.7%) compared to placebo (2.2%).

However, one fatal case of klebsiella pneumonia sepsis occurred in a patient taking Феморикс 14 mg for 1.7 years. Fatal infections have been reported in the postmarketing setting in patients receiving leflunomide, especially Pneumocystis jiroveci pneumonia and aspergillosis. Most of the reports were confounded by concomitant immunosuppressant therapy and/or comorbid illness which, in addition to rheumatoid disease, may predispose patients to infection. In clinical studies with Феморикс, cytomegalovirus hepatitis reactivation has been observed.

In clinical studies with Феморикс, cases of tuberculosis have been observed. Prior to initiating Феморикс, screen patients for latent tuberculosis infection with a tuberculin skin test or with a blood test for mycobacterium tuberculosis infection. Феморикс has not been studied in patients with a positive tuberculosis screen, and the safety of Феморикс in individuals with latent tuberculosis infection is unknown. For patients testing positive in tuberculosis screening, treat by standard medical practice prior to therapy with Феморикс.

Vaccination

No clinical data are available on the efficacy and safety of live vaccinations in patients taking Феморикс. Vaccination with live vaccines is not recommended. The long half-life of Феморикс should be considered when contemplating administration of a live vaccine after stopping Феморикс.

Malignancy

The risk of malignancy, particularly lymphoproliferative disorders, is increased with the use of some immunosuppressive medications. There is a potential for immunosuppression with Феморикс. No apparent increase in the incidence of malignancies and lymphoproliferative disorders was reported in the Феморикс clinical trials, but larger and longer-term studies would be needed to determine whether there is an increased risk of malignancy or lymphoproliferative disorders with Феморикс.

Hypersensitivity And Serious Skin Reactions

Феморикс can cause anaphylaxis and severe allergic reactions. Signs and symptoms have included dyspnea, urticaria, and angioedema including lips, eyes, throat, and tongue.

Cases of serious skin reactions, including cases of Stevens-Johnson syndrome (SJS) and a fatal case of toxic epidermal necrolysis (TEN), have been reported with Феморикс.

In patients treated with leflunomide, the parent compound, very rare cases of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) have also been reported.

Inform patients of the signs and symptoms of anaphylaxis and angioedema and signs and symptoms that may signal a serious skin reaction. Inform patients that a fever associated with signs of other organ system involvement (e.g., rash, lymphadenopathy, or hepatic dysfunction) may be drug-related. Instruct patients to discontinue Феморикс and seek immediate medical care should these signs and symptoms occur. Discontinue Феморикс, unless the reactions are clearly not drug-related, and begin an accelerated elimination procedure immediately. In such cases, patients should not be re-exposed to teriflunomide.

Peripheral Neuropathy

In placebo-controlled studies, peripheral neuropathy, including both polyneuropathy and mononeuropathy (e.g., carpal tunnel syndrome), occurred more frequently in patients taking Феморикс than in patients taking placebo. The incidence of peripheral neuropathy confirmed by nerve conduction studies was 1.4% (13 patients) and 1.9% (17 patients) of patients receiving 7 mg and 14 mg of Феморикс, respectively, compared with 0.4% receiving placebo (4 patients). Treatment was discontinued in 0.7% (8 patients) with confirmed peripheral neuropathy (3 patients receiving Феморикс 7 mg and 5 patients receiving Феморикс 14 mg). Five of them recovered following treatment discontinuation. Not all cases of peripheral neuropathy resolved with continued treatment. Peripheral neuropathy also occurred in patients receiving leflunomide.

Age older than 60 years, concomitant neurotoxic medications, and diabetes may increase the risk for peripheral neuropathy. If a patient taking Феморикс develops symptoms consistent with peripheral neuropathy, such as bilateral numbness or tingling of hands or feet, consider discontinuing Феморикс therapy and performing an accelerated elimination procedure.

Increased Blood Pressure

In placebo-controlled studies, the mean change from baseline to the end of study in systolic blood pressure was +2.3 mmHg and +2.7 mmHg for Феморикс 7 mg and 14 mg, respectively, and -0.6 mmHg for placebo. The change from baseline in diastolic blood pressure was +1.4 mmHg and +1.9 mmHg for Феморикс 7 mg and 14 mg, respectively, and -0.3 mmHg for placebo. Hypertension was an adverse reaction in 3.1% and 4.3% of patients treated with 7 mg or 14 mg of Феморикс compared with 1.8% for placebo. Check blood pressure before start of Феморикс treatment and periodically thereafter. Elevated blood pressure should be appropriately managed during treatment with Феморикс.

Respiratory Effects

Interstitial lung disease, including acute interstitial pneumonitis, has been reported with Феморикс in the postmarketing setting.

Interstitial lung disease and worsening of pre-existing interstitial lung disease have been reported during treatment with leflunomide. Interstitial lung disease may be fatal and may occur acutely at any time during therapy with a variable clinical presentation. New onset or worsening pulmonary symptoms, such as cough and dyspnea, with or without associated fever, may be a reason for discontinuation of therapy and for further investigation as appropriate. If discontinuation of the drug is necessary, consider initiation of an accelerated elimination procedure.

Concomitant Use With Immunosuppressive Or Immunomodulating Therapies

Coadministration with antineoplastic or immunosuppressive therapies used for treatment of multiple sclerosis has not been evaluated. Safety studies in which Феморикс was concomitantly administered with other immune modulating therapies for up to one year (interferon beta, glatiramer acetate) did not reveal any specific safety concerns. The long term safety of these combinations in the treatment of multiple sclerosis has not been established.

In any situation in which the decision is made to switch from Феморикс to another agent with a known potential for hematologic suppression, it would be prudent to monitor for hematologic toxicity, because there will be overlap of systemic exposure to both compounds. Use of an accelerated elimination procedure may decrease this risk, but may also potentially result in return of disease activity if the patient had been responding to Феморикс treatment.

Patient Counseling Information

Advise the patient to read the FDA-approved patient labeling (Medication Guide).

A Medication Guide is required for distribution with Феморикс.

Hepatotoxicity

Inform patients that Феморикс may increase liver enzymes and that their liver enzymes will be checked before starting Феморикс and for at least 6 months while they are taking Феморикс. Advise patients that they should contact their physician if they have any unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, or jaundice and/or dark urine.

Importance Of Preventing Pregnancy

• Inform patients that based on animal studies, Феморикс may cause fetal harm.
• Advise females of reproductive potential of the need for effective contraception during Феморикс treatment and until completion of an accelerated elimination procedure. Advise them that an accelerated elimination procedure can be used at any time after the discontinuation of Феморикс.
• Instruct the patient that if she suspects or confirms pregnancy, she should immediately inform her physician.
• Instruct men taking Феморикс and not wishing to father a child to use effective contraception to minimize any possible risk to the fetus; their female partners should also use effective contraception.
• Advise men wishing to father a child to discontinue use of Феморикс and undergo an accelerated elimination procedure.

Pregnancy Exposure Registry

There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to Феморикс during pregnancy.

Availability Of An Accelerated Elimination Procedure

Advise patients that Феморикс may stay in the blood for up to 2 years after the last dose and that an accelerated elimination procedure may be used if needed.

Risk Of Infections

Inform patients that they may develop a lowering of their white blood cell counts and that their blood counts will be checked before starting Феморикс.

Inform patients that they may be more likely to get infections when taking Феморикс and that they should contact their physician if they develop symptoms of infection, particularly in case of fever.

Advise patients that the use of some vaccines should be avoided during treatment with Феморикс and for at least 6 months after discontinuation.

Serious Allergic Reactions

Advise patients to discontinue Феморикс and seek immediate medical attention if any signs or symptoms of a hypersensitivity reaction occur. Signs and symptoms include dyspnea, urticaria, and angioedema including lips, eyes, throat, and tongue or skin rash.

Peripheral Neuropathy

Inform patients that they may develop peripheral neuropathy. Advise patients that they should contact their physician if they develop symptoms of peripheral neuropathy, such as numbness or tingling of hands or feet.

Increased Blood Pressure

Inform patients that Феморикс may increase blood pressure.

Lactation

Inform patients that it is not known whether this drug is present in human milk. Advise patients, if they are considering breastfeeding, to discuss this with their healthcare provider to decide if they will take Феморикс or breastfeed. Advise patients that they should not do both.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

Carcinogenesis

No evidence of carcinogenicity was observed in lifetime carcinogenicity bioassays in mouse and rat. In mouse, teriflunomide was administered orally at doses up to 12 mg/kg/day for up to 95-104 weeks; plasma teriflunomide exposures (AUC) at the highest dose tested are approximately 3 times that in humans at the maximum recommended human dose (MRHD, 14 mg/day). In rat, teriflunomide was administered orally at doses up to 4 mg/kg/day for up to 97-104 weeks; plasma teriflunomide AUCs at the highest doses tested are less than that in humans at the MRHD.

Mutagenesis

Teriflunomide was negative in the in vitro bacterial reverse mutation (Ames) assay, the in vitro HPRT assay, and in in vivo micronucleus and chromosomal aberration assays. Teriflunomide was positive in an in vitro chromosomal aberration assay in human lymphocytes, with and without metabolic activation. Addition of uridine (to supplement the pyrimidine pool) reduced the magnitude of the clastogenic effect; however, teriflunomide was positive in the in vitro chromosomal aberration assay, even in the presence of uridine.

4-Trifluoromethylaniline (4-TFMA), a minor metabolite of teriflunomide, was positive in the in vitro bacterial reverse mutation (Ames) assay, the in vitro HPRT assay, and the in vitro chromosomal aberration assay in mammalian cells. 4-TFMA was negative in in vivo micronucleus and chromosomal aberration assays.

Impairment Of fertility

Oral administration of teriflunomide (0, 1, 3, 10 mg/kg/day) to male rats prior to and during mating (to untreated females) resulted in no adverse effects on fertility; however, reduced epididymal sperm count was observed at the mid and high doses tested. The no-effect dose for reproductive toxicity in male rats (1 mg/kg) is less than the MRHD on a mg/m² basis.

Oral administration of teriflunomide (0, 0.84, 2.6, 8.6 mg/kg/day) to female rats, prior to and during mating (to untreated males) and continuing to gestation day 6, resulted in embryolethality, reduced fetal body weight, and/or malformations at all doses tested. Due to marked embryolethality at the highest dose tested, no fetuses were available for evaluation. The lowest dose tested is less than the MRHD on a mg/m² basis.

Use In Specific Populations

Pregnancy

Pregnancy Exposure Registry

There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to Феморикс during pregnancy. Healthcare providers and patients are encouraged to report pregnancies by calling 1-800-745-4447, option 2.

Risk Summary

Феморикс is contraindicated for use in pregnant women and females of reproductive potential not using effective contraception because of the potential for fetal harm based on animal data. Human data are not available at this time to inform the presence or absence of drug-associated risk with the use of Феморикс during pregnancy.

In animal reproduction studies in rat and rabbits, oral administration of teriflunomide during organogenesis caused teratogenicity and embryolethality at plasma exposures (AUC) lower than that at the maximum human recommended dose (MHRD) of 14 mg/day.

In the US general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2%-4% and 15%-20%, respectively. The background risk of major birth defects and miscarriage in the indicated population is unknown.

Clinical Considerations

Women who wish to become pregnant should discontinue use of Феморикс and undergo an accelerated elimination procedure to decrease the plasma concentration of teriflunomide to less than 0.02 mg/L (0.02 mcg/mL). Effective contraception should be used until is it verified that plasma concentrations of teriflunomide are less than 0.02 mg/L (0.02 mcg/mL). Human plasma concentrations of teriflunomide less than 0.02 mg/L (0.02 mcg/mL) are expected to have minimal embryofetal risk.

If the patient becomes pregnant while taking this drug, stop treatment with Феморикс, inform the patient of the potential risk to the fetus, and perform the accelerated drug elimination procedure to achieve plasma concentrations of less than 0.02 mg/L (0.02 mcg/mL). Refer the patient to an obstetrician/gynecologist, preferably experienced in reproductive toxicity, for further evaluation and counseling.

Data

Animal Data

When teriflunomide (oral doses of 1, 3, or 10 mg/kg/day) was administered to pregnant rats throughout the period of organogenesis, high incidences of fetal malformation (primarily craniofacial, and axial and appendicular skeletal defects) and embryofetal death were observed at doses not associated with maternal toxicity. Adverse effects on embryofetal development were observed following dosing at various stages throughout organogenesis. Maternal plasma exposure at the no-effect level (1.0 mg/kg/day) for embryofetal developmental toxicity in rats was less than that in humans at the maximum recommended human dose (MRHD, 14 mg/day).

Administration of teriflunomide (oral doses of 1, 3.5, or 12 mg/kg/day) to pregnant rabbits throughout organogenesis resulted in high incidences of fetal malformation (primarily craniofacial, and axial and appendicular skeletal defects) and embryofetal death at doses associated with minimal maternal toxicity. Maternal plasma exposure at the no-effect dose (1.0 mg/kg/day) for embryofetal developmental toxicity in rabbits was less than that in humans at the MRHD.

In studies in which teriflunomide (oral doses of 0.05, 0.1, 0.3, 0.6, or 1.0 mg/kg/day) was administered to rats during gestation and lactation, decreased growth, eye and skin abnormalities, and high incidences of malformation (limb defects) and postnatal death were observed in the offspring at doses not associated with maternal toxicity. Maternal plasma exposure at the no-effect dose for pre-and postnatal developmental toxicity in rats (0.10 mg/kg/day) was less than that in humans at the MRHD.

In animal reproduction studies of leflunomide, embryolethality and teratogenic effects were observed in pregnant rat and rabbit at or below clinically relevant plasma teriflunomide exposures (AUC). In published reproduction studies in pregnant mice, leflunomide was embryolethal and increased the incidence of malformations (craniofacial, axial skeletal, heart and great vessel). Supplementation with exogenous uridine reduced the teratogenic effects in pregnant mice, suggesting that the mode of action (inhibition of mitochondrial enzyme dihydroorotate dehydrogenase) is the same for therapeutic efficacy and developmental toxicity.

At recommended doses in humans, teriflunomide and leflunomide result in a similar range of plasma concentrations of teriflunomide.

Lactation

Risk Summary

It is not known whether this drug is excreted in human milk. Teriflunomide was detected in rat milk following a single oral dose.

The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Феморикс and any potential adverse effects on the breastfed infant from Феморикс or from the underlying maternal condition.

Females And Males Of Reproductive Potential

Pregnancy Testing

Exclude pregnancy prior to initiation of treatment with Феморикс in females of reproductive potential. Advise females to notify their healthcare provider immediately if pregnancy occurs or is suspected during treatment.

Contraception

Females

Females of reproductive potential should use effective contraception while taking Феморикс. If Феморикс is discontinued, use of contraception should be continued until is it verified that plasma concentrations of teriflunomide are less than 0.02 mg/L (0.02 mcg/mL).

Females of reproductive potential who wish to become pregnant should undergo an accelerated elimination procedure. Effective contraception should be used until it is verified that plasma concentrations of teriflunomide are less than 0.02 mg/L (0.02 mcg/mL).

Males

Феморикс is detected in human semen. Animal studies to specifically evaluate the risk of male-mediated fetal toxicity have not been conducted. To minimize any possible risk, men not wishing to father a child and their female partners should use effective contraception. Men wishing to father a child should discontinue use of Феморикс and either undergo an accelerated elimination procedure or wait until verification that the plasma teriflunomide concentration is less than 0.02 mg/L (0.02 mcg/mL).

Infertility

Administration of teriflunomide to male rats resulted in no adverse effects on fertility. However, reduced epididymal sperm count was observed. Effects of Феморикс on fertility in humans have not been evaluated.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Geriatric Use

Clinical studies of Феморикс did not include patients over 65 years old.

Hepatic Impairment

No dosage adjustment is necessary for patients with mild and moderate hepatic impairment. The pharmacokinetics of teriflunomide in severe hepatic impairment has not been evaluated. Феморикс is contraindicated in patients with severe hepatic impairment.

Renal Impairment

No dosage adjustment is necessary for patients with mild, moderate, and severe renal impairment.

The following serious adverse reactions are described elsewhere in the prescribing information:

• Hepatotoxicity
• Bone Marrow Effects/Immunosuppression Potential/Infections
• Hypersensitivity and Serious Skin Reactions
• Peripheral Neuropathy
• Increased Blood Pressure
• Respiratory Effects

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 clinical practice.

A total of 2047 patients receiving Феморикс (7 mg or 14 mg once daily) constituted the safety population in the pooled analysis of placebo controlled studies in patients with relapsing forms of multiple sclerosis; of these, 71% were female. The average age was 37 years.

Table 1 lists adverse reactions in placebo-controlled trials with rates that were at least 2% for Феморикс patients and also at least 2% above the rate in placebo patients. The most common were headache, an increase in ALT, diarrhea, alopecia, and nausea. The adverse reaction most commonly associated with discontinuation was an increase in ALT (3.3%, 2.6%, and 2.3% of all patients in the Феморикс 7 mg, Феморикс 14 mg, and placebo treatment arms, respectively).

Table 1. Adverse Reactions in Pooled Placebo-Controlled Studies in Patients with Relapsing Forms of Multiple Sclerosis

Cardiovascular Deaths

Four cardiovascular deaths, including three sudden deaths, and one myocardial infarction in a patient with a history of hyperlipidemia and hypertension were reported among approximately 2600 patients exposed to Феморикс in the premarketing database. These cardiovascular deaths occurred during uncontrolled extension studies, one to nine years after initiation of treatment. A relationship between Феморикс and cardiovascular death has not been established.

Acute Renal Failure

In placebo-controlled studies, creatinine values increased more than 100% over baseline in 8/1045 (0.8%) patients in the 7 mg Феморикс group and 6/1002 (0.6%) patients in the 14 mg Феморикс group versus 4/997 (0.4%) patients in the placebo group. These elevations were transient. Some elevations were accompanied by hyperkalemia. Феморикс may cause acute uric acid nephropathy with transient acute renal failure because Феморикс increases renal uric acid clearance.

Hypophosphatemia

In clinical trials, 18% of Феморикс-treated patients had hypophosphatemia with serum phosphorus levels of at least 0.6 mmol/L, compared to 7% of placebo-treated patients; 4% of Феморикс-treated patients had hypophosphatemia with serum phosphorus levels at least 0.3 mmol/L but less than 0.6 mmol/L, compared to 0.8% of placebo-treated patients. No patient in any treatment group had a serum phosphorus below 0.3 mmol/L.

Postmarketing Experience

The following adverse reactions have been identified during postapproval use of Феморикс. 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.

• Hypersensitivity reactions, some of which were severe, such as anaphylaxis and angioedema
• Severe skin reactions, including toxic epidermal necrolysis and Stevens-Johnson syndrome
• Thrombocytopenia
• Interstitial lung disease
• Pancreatitis

There is no experience regarding teriflunomide overdose or intoxication in humans. Teriflunomide 70 mg daily up to 14 days was well tolerated by healthy subjects.

In the event of clinically significant overdose or toxicity, cholestyramine or activated charcoal is recommended to accelerate elimination.

Potential To Prolong The QT Interval

In a placebo controlled thorough QT study performed in healthy subjects, there was no evidence that teriflunomide caused QT interval prolongation of clinical significance (i.e., the upper bound of the 90% confidence interval for the largest placebo-adjusted, baseline-corrected QTc was below 10 ms).

Teriflunomide is the principal active metabolite of leflunomide and is responsible for leflunomide’s activity in vivo. At recommended doses, teriflunomide and leflunomide result in a similar range of plasma concentrations of teriflunomide.

Based on a population analysis of teriflunomide in healthy volunteers and MS patients, median t_1/2 was approximately 18 and 19 days after repeated doses of 7 mg and 14 mg respectively. It takes approximately 3 months respectively to reach steady-state concentrations. The estimated AUC accumulation ratio is approximately 30 after repeated doses of 7 or 14 mg.

Absorption

Median time to reach maximum plasma concentrations is between 1 to 4 hours post dose following oral administration of teriflunomide.

Food does not have a clinically relevant effect on teriflunomide pharmacokinetics.

Distribution

Teriflunomide is extensively bound to plasma protein (>99%) and is mainly distributed in plasma. The volume of distribution is 11 L after a single intravenous (IV) administration.

Metabolism

Teriflunomide is the major circulating moiety detected in plasma. The primary biotransformation pathway to minor metabolites of teriflunomide is hydrolysis, with oxidation being a minor pathway. Secondary pathways involve oxidation, N-acetylation and sulfate conjugation.

Elimination

Teriflunomide is eliminated mainly through direct biliary excretion of unchanged drug as well as renal excretion of metabolites. Over 21 days, 60.1% of the administered dose is excreted via feces (37.5%) and urine (22.6%). After an accelerated elimination procedure with cholestyramine, an additional 23.1% was recovered (mostly in feces). After a single IV administration, the total body clearance of teriflunomide is 30.5 mL/h.