Teriflunomide

There was an increase in mean repaglinide C_max and AUC (1.7- and 2.4-fold, respectively), following repeated doses of teriflunomide, suggesting that teriflunomide is an inhibitor of CYP2C8 in vivo. Therefore, medicinal products metabolised by CYP2C8, such as repaglinide, paclitaxel, pioglitazone or rosiglitazone, should be used with caution during treatment with teriflunomide.

There was an increase in mean cefaclor C_max and AUC (1.43- and 1.54-fold, respectively), following repeated doses of teriflunomide, suggesting that teriflunomide is an inhibitor of OAT3 in vivo. Therefore, when teriflunomide is coadministered with substrates of OAT3, such as cefaclor, benzylpenicillin, ciprofloxacin, indometacin, ketoprofen, furosemide, cimetidine, methotrexate, zidovudine, caution is recommended.

There was an increase in mean rosuvastatin C_max and AUC (2.65- and 2.51-fold, respectively), following repeated doses of teriflunomide. However, there was no apparent impact of this increase in plasma rosuvastatin exposure on the HMG-CoA reductase activity. For rosuvastatin, a dose reduction by 50% is recommended for coadministration with teriflunomide. For other substrates of BCRP (e.g. methotrexate, topotecan, sulfasalazine, daunorubicin, doxorubicin) and the OATP family especially HMG-Co reductase inhibitors (e.g. simvastatin, atorvastatin, pravastatin, methotrexate, nateglinide, repaglinide, rifampicin) concomitant administration of teriflunomide should also be undertaken with caution. Patients should be closely monitored for signs and symptoms of excessive exposure to the medicinal products and reduction of the dose of these medicinal products should be considered.

The use of live attenuated vaccines may carry a risk of infections and should therefore be avoided.

Repeated doses of teriflunomide decreased mean C_max and AUC of caffeine (CYP1A2 substrate) by 18% and 55%, respectively, suggesting that teriflunomide may be a weak inducer of CYP1A2 in vivo. Therefore, medicinal products metabolised by CYP1A2 (such as duloxetine, alosetron, theophylline and tizanidine) should be used with caution during treatment with teriflunomide, as it could lead to the reduction of the efficacy of these medicinal products.

Effect of teriflunomide on oral contraceptives: 0.03 mg ethinylestradiol and 0.15 mg levonorgestrel There was an increase in mean ethinylestradiol C_max and AUC_0-24 (1.58- and 1.54-fold, respectively) and levonorgestrel C_max and AUC_0-24 (1.33- and 1.41-fold, respectively) following repeated doses of teriflunomide. While this interaction of teriflunomide is not expected to adversely impact the efficacy of oral contraceptives, it should be considered when selecting or adjusting oral contraceptive treatment used in combination with teriflunomide.

It is recommended that patients receiving teriflunomide are not treated with cholestyramine or activated charcoal because this leads to a rapid and significant decrease in plasma concentration unless an accelerated elimination is desired. The mechanism is thought to be by interruption of enterohepatic recycling and/or gastrointestinal dialysis of teriflunomide.

Based on the half-life of fingolimod, a 6-week interval without therapy is needed for clearance from the circulation and a 1 to 2 month period is needed for lymphocytes to return to normal range following discontinuation of fingolimod. Starting teriflunomide during this interval will result in concomitant exposure to fingolimod. This may lead to an additive effect on the immune system and caution is, therefore, indicated.

As leflunomide is the parent compound of teriflunomide, co-administration of teriflunomide with leflunomide is not recommended.

Due to the long half-life of natalizumab, concomitant exposure, and thus concomitant immune effects, could occur for up to 2-3 months following discontinuation of natalizumab if teriflunomide was immediately started. Therefore, caution is required when switching patients from natalizumab to teriflunomide.

Co-administration of repeated doses (600 mg once daily for 22 days) of rifampicin (a CYP2B6, 2C8, 2C9, 2C19, 3A inducer), as well as an inducer of the efflux transporters P-glycoprotein [P-gp] and breast cancer resistant protein [BCRP] with teriflunomide (70 mg single dose) resulted in an approximately 40% decrease in teriflunomide exposure. Rifampicin and other known potent CYP and transporter inducers such as carbamazepine, phenobarbital, phenytoin and St. John’s Wort should be used with caution during the treatment with teriflunomide.

Repeated doses of teriflunomide had no effect on the pharmacokinetics of S-warfarin, indicating that teriflunomide is not an inhibitor or an inducer of CYP2C9. However, a 25% decrease in peak international normalised ratio (INR) was observed when teriflunomide was coadministered with warfarin as compared with warfarin alone. Therefore, when warfarin is co-administered with teriflunomide, close INR follow-up and monitoring is recommended.

The measurement of ionised calcium levels might show falsely decreased values under treatment with leflunomide and/or teriflunomide (the active metabolite of leflunomide) depending on the type of ionised calcium analyser used (e.g. blood gas analyser). Therefore, the plausibility of observed decreased ionised calcium levels needs to be questioned in patients under treatment with leflunomide or teriflunomide. In case of doubtful measurements, it is recommended to determine the total albumin adjusted serum calcium concentration.

There are limited amount of data from the use of teriflunomide in pregnant women. Studies in animals have shown reproductive toxicity.

Teriflunomide may cause serious birth defects when administered during pregnancy. Teriflunomide is contraindicated in pregnancy.

Women of childbearing potential have to use effective contraception during treatment and after treatment as long as teriflunomide plasma concentration is above 0.02 mg/l. During this period women should discuss any plans to stop or change contraception with the treating physician. Female children and/or parents/caregivers of female children should be informed about the need to contact the treating physician once the female child under teriflunomide treatment experiences menses. Counselling should be provided to the new patients of child-bearing potential about contraception and the potential risk to the foetus. Referral to a gynaecologist should be considered.

The patient must be advised that if there is any delay in onset of menses or any other reason to suspect pregnancy, they must discontinue teriflunomide and notify the physician immediately for pregnancy testing, and if positive, the physician and patient must discuss the risk to the pregnancy. It is possible that rapidly lowering the blood level of teriflunomide, by instituting the accelerated elimination procedure described below, at the first delay of menses, may decrease the risk to the foetus. For women receiving teriflunomide treatment, who wish to become pregnant, the medicinal product should be stopped and an accelerated elimination procedure is recommended in order to more rapidly achieve concentration below 0.02 mg/l (see below).

If an accelerated elimination procedure is not used, teriflunomide plasma levels can be expected to be above 0.02 mg/l for an average of 8 months, however, in some patients it may take up to 2 years to reach plasma concentration below 0.02 mg/l. Therefore, teriflunomide plasma concentrations should be measured before a woman begins to attempt to become pregnant. Once the teriflunomide plasma concentration is determined to be below 0.02 mg/l, the plasma concentration must be determined again after an interval of at least 14 days. If both plasma concentrations are below 0.02 mg/l, no risk to the foetus is to be expected. For further information on the sample testing please contact the Marketing Authorisation Holder or its local representative.

Accelerated elimination procedure

After stopping treatment with teriflunomide:

• cholestyramine 8 g is administered 3 times daily for a period of 11 days, or cholestyramine 4 g three times a day can be used, if cholestyramine 8 g three times a day is not well tolerated,
• alternatively, 50 g of activated powdered charcoal is administered every 12 hours for a period of 11 days.

However, also following either of the accelerated elimination procedures, verification by 2 separate tests at an interval of at least 14 days and a waiting period of one-and-a-half months between the first occurrence of a plasma concentration below 0.02 mg/l and fertilisation is required.

Both cholestyramine and activated powdered charcoal may influence the absorption of oestrogens and progestogens such that reliable contraception with oral contraceptives may not be guaranteed during the accelerated elimination procedure with cholestyramine or activated powdered charcoal. Use of alternative contraceptive methods is recommended.

Animal studies have shown excretion of teriflunomide in milk. Teriflunomide is contraindicated during breast-feeding.

Use in males

The risk of male-mediated embryo-foetal toxicity through teriflunomide treatment is considered low.

Fertility

Results of studies in animals have not shown an effect on fertility. Although human data are lacking, no effect on male and female fertility is anticipated.

Teriflunomide has no or negligible influence on the ability to drive and use machines. In the case of adverse reactions such as dizziness, which has been reported with leflunomide, the parent compound, the patient’s ability to concentrate and to react properly may be impaired. In such cases, patients should refrain from driving and using machines.

Summary of the safety profile

The most frequently reported adverse reactions in the teriflunomide treated (7 mg and 14 mg) patients were: headache (17.8%, 15.7%), diarrhoea (13.1%, 13.6%) increased ALT (13%, 15%), nausea (8%, 10.7%), and alopecia (9.8%, 13.5%). In general, headache, diarrhoea, nausea and alopecia, were mild to moderate, transient and infrequently led to treatment discontinuation.

Teriflunomide is the main metabolite of leflunomide. The safety profile of leflunomide in patients suffering from rheumatoid arthritis or psoriatic arthritis may be pertinent when prescribing teriflunomide in MS patients.

Tabulated list of adverse reactions

Teriflunomide was evaluated in a total of 2,267 patients exposed to teriflunomide (1,155 on teriflunomide 7 mg and 1,112 on teriflunomide 14 mg) once daily for a median duration of about 672 days in four placebo-controlled studies (1,045 and 1,002 patients for teriflunomide 7 mg and 14 mg, respectively) and one active comparator study (110 patients in each of the teriflunomide treatment groups) in adult patients with relapsing forms of MS (Relapsing Multiple Sclerosis, RMS).

Listed below are the adverse reactions reported with teriflunomide in placebo-controlled studies in adult patients, reported for teriflunomide 7 mg or 14 mg from clinical studies in adult patients. Frequencies were defined using the following convention: very common (≥1/10); common (≥1/100 to <1/10); uncommon (≥1/1,000 to <1/100); rare (≥1/10,000 to <1/1,000); very rare (<1/10,000); not known (cannot be estimated from the available data). Within each frequency grouping, adverse reactions are ranked in order of decreasing seriousness.

^a please refer to the detailed description section
^b frequency is “common” in children based on a controlled clinical study in paediatrics; frequency is “uncommon” in adults

Description of selected adverse reactions

Alopecia

Alopecia was reported as hair thinning, decreased hair density, hair loss, associated or not with hair texture change, in 13.9% of patients treated with 14 mg teriflunomide versus 5.1% in patients treated with placebo. Most cases were described as diffuse or generalised over the scalp (no complete hair loss reported) and occurred most often during the first 6 months and with resolution in 121 of 139 (87.1%) patients treated with teriflunomide 14 mg. Discontinuation because of alopecia was 1.3% in the teriflunomide 14 mg teriflunomide group, versus 0.1% in the placebo group.

Hepatic effects

During placebo-controlled studies in adult patients the following was detected:

Mild increases in transaminase, ALT below or equal to 3-fold ULN were more frequently seen in teriflunomide-treated groups as compared to placebo. The frequency of elevations above 3-fold ULN and higher was balanced across treatment groups. These elevations in transaminase occurred mostly within the first 6 months of treatment and were reversible after treatment cessation. The recovery time varied between months and years.

Blood pressure effects

In placebo-controlled studies in adult patients the following was established:

• systolic blood pressure was >140 mm Hg in 19.9% of patients receiving 14 mg/day teriflunomide as compared to 15.5% receiving placebo;
• systolic blood pressure was >160 mm Hg in 3.8% of patients receiving 14 mg/day teriflunomide as compared to 2.0% receiving placebo;
• diastolic blood pressure was >90 mm Hg in 21.4% of patients receiving 14 mg/day teriflunomide as compared to 13.6% receiving placebo.

Infections

In placebo-controlled studies in adult patients, no increase in serious infections was observed with teriflunomide 14 mg (2.7%) as compared to placebo (2.2%). Serious opportunistic infections occurred in 0.2% of each group. Severe infections including sepsis, sometimes fatal have been reported postmarketing.

Haematological effects

A mean decrease affecting white blood cell (WBC) count (<15% from baseline levels, mainly neutrophil and lymphocytes decrease) was observed in placebo-controlled trials with teriflunomide in adult patients, although a greater decrease was observed in some patients. The decrease in mean count from baseline occurred during the first 6 weeks then stabilised over time while on-treatment but at decreased levels (less than a 15% decrease from baseline). The effect on red blood cell (RBC) (<2%) and platelet counts (<10%) was less pronounced.

Peripheral neuropathy

In placebo-controlled studies in adult patients, peripheral neuropathy, including both polyneuropathy and mononeuropathy (e.g., carpal tunnel syndrome), was reported more frequently in patients taking teriflunomide than in patients taking placebo. In the pivotal, placebo-controlled studies, the incidence of peripheral neuropathy confirmed by nerve conduction studies was 1.9% (17 patients out of 898) on 14 mg of teriflunomide, compared with 0.4% (4 patients out of 898) on placebo. Treatment was discontinued in 5 patients with peripheral neuropathy on teriflunomide 14 mg. Recovery following treatment discontinuation was reported in 4 of these patients.

Neoplasms benign, malignant and unspecified (incl. cysts and polyps)

There does not appear to be an increased risk of malignancy with teriflunomide in the clinical trial experience. The risk of malignancy, particularly lymphoproliferative disorders, is increased with use of some other agents that affect the immune system (class effect).

Severe skin reactions

Cases of severe skin reactions have been reported with teriflunomide post-marketing.

Asthenia

In placebo-controlled studies in adult patients, frequencies for asthenia were 2.0%, 1.6% and 2.2% in the placebo, teriflunomide 7 mg and teriflunomide 14 mg group, respectively.

Psoriasis

In placebo-controlled studies, frequencies for psoriasis were 0.3%, 0.3% and 0.4% in the placebo, teriflunomide 7 mg and teriflunomide 14 mg group, respectively.

Gastrointestinal disorders

Pancreatitis has been reported infrequently in the post-marketing setting with teriflunomide in adults, including cases of necrotising pancreatitis and pancreatic pseudocyst. Pancreatic events may occur at any time during treatment with teriflunomide, which may lead to hospitalisation and/or require corrective treatment.

Paediatric population

The observed safety profile in paediatric patients (from 10 to 17 years-old) receiving teriflunomide daily was overall similar to that seen in adult patients. However, in the paediatric study (166 patients: 109 in the teriflunomide group and 57 in the placebo group), cases of pancreatitis were reported in 1.8% (2/109) of the teriflunomide-treated patients compared to none in the placebo group, in the double-blind phase. One of these events led to hospitalisation and required corrective treatment. In paediatric patients treated with teriflunomide in the open-label phase of the study, 2 additional cases of pancreatitis (one was reported as a serious event, the other was a nonserious event of mild intensity) and one case of serious acute pancreatitis (with pseudo-papilloma), were reported. In two of these 3 patients, pancreatitis led to hospitalisation. Clinical symptoms included abdominal pain, nausea and/ or vomiting and serum amylase and lipase were elevated in these patients. All patients recovered after treatment discontinuation and accelerated elimination procedure and corrective treatment.

The following adverse reactions were more frequently reported in the paediatric population than in the adult population:

• Alopecia was reported in 22.0% of patients treated with teriflunomide versus 12.3% in patients treated with placebo.
• Infections were reported in 66.1% of patients treated with teriflunomide versus 45.6% in patients treated with placebo. Among them, nasopharyngitis and upper respiratory tract infections were more frequently reported with teriflunomide.
• CPK increase was reported in 5.5% of patients treated with teriflunomide versus 0% in patients treated with placebo. The majority of the cases were associated with documented physical exercise.
• Paraesthesia was reported in 11.0% of patients treated with teriflunomide versus 1.8% in patients treated with placebo.
• Abdominal pain was reported in 11.0% of patients treated with teriflunomide versus 1.8% in patients treated with placebo.