FENFLURAMINE Drug Interactions: What You Need to Know

INTERACTIONS Dose adjustment is required for patients taking stiripentol plus clobazam. ( 2.2 , 2.3 , 7.1 ) Strong CYP1A2 or CYP2D6 inhibitors: a dose adjustment is recommended ( 2.3 , 7.1 ) Strong CYP1A2, CYP2B6, or CYP3A4 inducers: it is recommended to avoid coadministration with FINTEPLA. If coadministration is necessary, consider a FINTEPLA dosage increase. ( 7.1 )

7.1 Effect of Other Drugs on FINTEPLA Stiripentol Plus Clobazam Coadministration of FINTEPLA with stiripentol plus clobazam, with or without valproate, increases fenfluramine plasma concentrations <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span>. If FINTEPLA is coadministered with stiripentol plus clobazam, the maximum daily dosage of FINTEPLA is 0.2 mg/kg twice daily (maximum daily dosage of 17 mg) <span class="opacity-50 text-xs">[see Dosage and Administration (2.2) ]</span> . Strong CYP1A2, CYP2B6, or CYP3A Inducers Coadministration of FINTEPLA with strong CYP1A2, CYP2B6, or CYP3A inducers will decrease fenfluramine plasma concentrations, which may lower the efficacy of FINTEPLA <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> . It is recommended to avoid coadministration of strong CYP1A2, CYP2B6 or CYP3A inducers. If coadministration of a strong CYP1A2, CYP2B6, or CYP3A inducer with FINTEPLA is necessary, monitor the patient for reduced efficacy and consider increasing the dosage of FINTEPLA as needed; however, do not exceed the maximum daily dosage of FINTEPLA <span class="opacity-50 text-xs">[see Dosage and Administration (2.2) ]</span>. If a strong CYP1A2, CYP2B6, or CYP3A inducer is discontinued during maintenance treatment with FINTEPLA, consider gradual reduction in the FINTEPLA dosage to the dose administered prior to initiating the inducer <span class="opacity-50 text-xs">[see Warnings and Precautions (5.6) ]</span>. Strong CYP1A2 or CYP2D6 Inhibitors Coadministration of FINTEPLA with strong CYP1A2 or CYP2D6 inhibitors will increase fenfluramine plasma concentrations <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> . If FINTEPLA is coadministered with strong CYP1A2 or CYP2D6 inhibitors, the maximum daily dosage of FINTEPLA is 20 mg <span class="opacity-50 text-xs">[see Dosage and Administration (2.3) ]</span>. If a strong CYP1A2 or CYP2D6 inhibitor is discontinued during maintenance treatment with FINTEPLA, consider gradual increase in the FINTEPLA dosage to the dose recommended without CYP1A2 or CYP2D6 inhibitors; however, do not exceed the maximum daily dosage of FINTEPLA <span class="opacity-50 text-xs">[see Dosage and Administration (2.2) ]</span>. If FINTEPLA is coadministered with stiripentol and a strong CYP1A2 or CYP2D6 inhibitor, do not exceed the maximum daily dosage of FINTEPLA of 17 mg <span class="opacity-50 text-xs">[see Dosage and Administration (2.3) ]</span>.

7.2 Effects of Serotonin Receptor Antagonists Cyproheptadine and potent 5-HT1A, 5-HT1D, 5-HT2A, and 5-HT2C serotonin receptor antagonists may decrease the efficacy of FINTEPLA. If cyproheptadine or potent 5--HT1A, 5--HT1D, 5-HT2A, or 5-HT2C serotonin receptor antagonists are coadministered with FINTEPLA, patients should be monitored appropriately.

7.3 Serotonergic Drugs Concomitant administration of FINTEPLA and drugs (e.g., SSRIs, SNRIs, TCAs, MAO inhibitors, trazodone, etc.), over-the-counter medications (e.g., dextromethorphan), or herbal supplements (e.g., St. John&apos;s Wort) that increase serotonin may increase the risk of serotonin syndrome <span class="opacity-50 text-xs">[see Warnings and Precautions (5.7) ]</span>. Concomitant use of FINTEPLA is contraindicated within 14 days of taking MAOIs. Use FINTEPLA with caution in patients taking other medications that increase serotonin.

FINTEPLA is contraindicated in patients with: Hypersensitivity to fenfluramine or any of the excipients in FINTEPLA [see Description (11) ] Concomitant use, or within 14 days of the administration, of monoamine oxidase inhibitors because of an increased risk of serotonin syndrome [see Warnings and Precautions (5.7) ] Hypersensitivity to fenfluramine or any of the excipients in FINTEPLA ( 4 )

Within

14 days of the administration of monoamine oxidase inhibitors due to an increased risk of serotonin syndrome ( 4 )

AND PRECAUTIONS Decreased Appetite and Decreased Weight: Advise patients that FINTEPLA can cause decreased appetite and decreased weight. ( 5.3 ) Somnolence, Sedation, and Lethargy: Monitor for somnolence and sedation. Advise patients not to drive or operate machinery until they have gained sufficient experience on FINTEPLA. ( 5.4 )

Suicidal

Behavior and Ideation: Monitor patients for suicidal behavior and thoughts. ( 5.5 ) Withdrawal of Antiepileptic Drugs: FINTEPLA should be gradually withdrawn to minimize the risk of increased seizure frequency and status epilepticus. ( 5.6 )

Serotonin

Syndrome: Advise patients that serotonin syndrome is a potentially life-threatening condition and may occur with FINTEPLA, particularly with concomitant administration of FINTEPLA with other serotonergic drugs. ( 5.7 ) Increase in Blood Pressure: Monitor blood pressure during treatment. ( 5.8 ) Glaucoma: Discontinue therapy in patients with acute decrease in visual acuity or ocular pain. ( 5.9 )

5.1 Valvular Heart Disease and Pulmonary Arterial Hypertension FINTEPLA can cause valvular heart disease (VHD) and pulmonary arterial hypertension (PAH). There is a known association between serotonergic drugs with 5-HT2B receptor agonist activity, including fenfluramine (the active ingredient in FINTEPLA), and valvular heart disease and pulmonary arterial hypertension. Although no patients receiving FINTEPLA developed valvular heart disease or pulmonary arterial hypertension in clinical trials for DS and LGS of up to 3 years in duration, cases of valvular heart disease and pulmonary arterial hypertension have been reported during use of FINTEPLA in the postmarketing setting <span class="opacity-50 text-xs">[see Boxed Warning and Adverse Reactions (6.1) ]</span> . Because of this risk, cardiac monitoring is required prior to starting treatment, during treatment, and after treatment with FINTEPLA concludes . Cardiac monitoring via echocardiogram can identify evidence of valvular heart disease and pulmonary arterial hypertension prior to a patient becoming symptomatic, aiding in early detection of these conditions.

Monitoring

Prior to starting treatment, patients must undergo an echocardiogram to evaluate for valvular heart disease and pulmonary arterial hypertension. Echocardiograms should be repeated every 6 months, and once 3-6 months post-treatment with FINTEPLA. The prescriber must consider the benefits versus the risks of initiating or continuing treatment with FINTEPLA if any of the following signs are observed via ECHO: Valvular abnormality or new abnormality via echocardiogram. VHD as indicated by mild or greater aortic regurgitation or moderate or greater mitral regurgitation, with additional characteristics of VHD (e.g., valve thickening or restrictive valve motion). PAH as indicated by elevated right heart/pulmonary artery pressure (PASP > 35 mm Hg). FINTEPLA is available only through a restricted program under a REMS [see Warnings and Precautions (5.2) ].

5.2 FINTEPLA REMS Program FINTEPLA is available only through a restricted distribution program called the FINTEPLA REMS program because of the risk of valvular heart disease and pulmonary arterial hypertension <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1) ]</span>. Notable requirements of the FINTEPLA REMS Program include: Prescribers must be certified by enrolling in the FINTEPLA REMS program. Prescribers must counsel patients receiving FINTEPLA about the risk of valvular heart disease and pulmonary arterial hypertension, how to recognize signs and symptoms of valvular heart disease and pulmonary arterial hypertension, the need for baseline (pretreatment) and periodic cardiac monitoring via echocardiogram during FINTEPLA treatment, and cardiac monitoring after FINTEPLA treatment. Patients must enroll in the REMS program and comply with ongoing monitoring requirements <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1) ]</span>. The pharmacy must be certified by enrolling in the REMS program and must only dispense to patients who are authorized to receive FINTEPLA. Wholesalers and distributors must only distribute to certified pharmacies. Further information is available at www.FinteplaREMS.com or by telephone at 1-877-964-3649.

5.3 Decreased Appetite and Decreased Weight FINTEPLA can cause decreases in appetite and weight. In placebo-controlled studies for DS (Study 1 and Study 2 combined), approximately 37% of patients treated with FINTEPLA reported, as an adverse reaction, decreased appetite and approximately 9% reported decreased weight, as compared to 8% and 1%, respectively, of patients on placebo . In the placebo- controlled study for LGS (Study 3), approximately 28% of patients treated with FINTEPLA reported, as an adverse reaction, decreased appetite and approximately 5% reported decreased weight, as compared to 15% and 2%, respectively, of patients on placebo <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span> . By the end of the controlled studies, 19% (Studies 1 and 2 combined) of DS patients and 7% (Study 3) of LGS patients treated with FINTEPLA had a measured decrease in weight of 7% or greater from their baseline weight, compared to 2% (Study 1 and 2) and 0% (Study 3) of patients on placebo. This measured decrease in weight appeared to be dose-related. In the controlled studies for DS, 26% of patients on FINTEPLA 0.7 mg/kg/day (Study 1), 19% of patients on FINTEPLA 0.4 mg/kg/day in combination with stiripentol (Study 2), and 13% of patients taking FINTEPLA 0.2 mg/kg/day (Study 1) experienced at least a 7% decrease in weight from baseline. In the controlled study for LGS, 9% of patients on FINTEPLA 0.7 mg/kg/day (Study 3) and 6% of patients on FINTEPLA 0.2 mg/kg/day (Study 3) experienced at least a 7% decrease in weight from baseline. Approximately half of the patients with LGS and most patients with DS resumed the expected measured increases in weight during the open-label extension studies. Given the frequency of these adverse reactions, the growth of pediatric patients treated with FINTEPLA should be carefully monitored. Weight should be monitored regularly during treatment with FINTEPLA, and dose modifications should be considered if a decrease in weight is observed.

5.4 Somnolence, Sedation, and Lethargy FINTEPLA can cause somnolence, sedation, and lethargy. In controlled studies for DS (Study 1 and Study 2 combined), the incidence of somnolence, sedation, and lethargy was 25% in patients treated with FINTEPLA, compared with 11% of patients on placebo. In the controlled study for LGS (Study 3), the incidence of somnolence, sedation, and lethargy was 19% in patients treated with FINTEPLA, compared with 16% of patients on placebo. In general, these effects may diminish with continued treatment <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span>. Other central nervous system (CNS) depressants, including alcohol, could potentiate these effects of FINTEPLA. Prescribers should monitor patients for somnolence and sedation and should advise patients not to drive or operate machinery until they have gained sufficient experience on FINTEPLA to gauge whether it adversely affects their ability to drive or operate machinery.

5.5 Suicidal Behavior and Ideation Antiepileptic drugs (AEDs), including FINTEPLA, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with an AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, or any unusual changes in mood or behavior. Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs that did not include FINTEPLA showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide. The increased risk of suicidal thoughts or behavior with AEDs was observed as early as 1 week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed. The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5-100 years) in the clinical trials analyzed.

Table

3 shows absolute and relative risk by indication for all evaluated AEDs.

Table

3: Risk of Suicidal Thoughts or Behaviors by Indication for Antiepileptic Drugs in the Pooled Analysis Indication Placebo Patients with Events per 1000 Patients Drug Patients with Events per 1000 Patients Relative Risk: Incidence of Events in Drug Patients/ Incidence in Placebo Patients Risk Difference: Additional Drug Patients with Events per 1000 Patients Epilepsy 1.0 3.4 3.5

2.4 Psychiatric 5.7 8.5 1.5

2.9 Other 1.0 1.8 1.9

0.9 Total 2.4 4.3 1.8

1.9 The relative risk for suicidal thoughts or behavior was higher in clinical trials in patients with epilepsy than in clinical trials in patients with psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications. Anyone considering prescribing FINTEPLA or any other AED must balance the risk of suicidal thoughts or behaviors with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.

5.6 Withdrawal of Antiepileptic Drugs As with most AEDs, FINTEPLA should generally be withdrawn gradually because of the risk of increased seizure frequency and status epilepticus. If withdrawal is needed because of a serious adverse reaction, rapid discontinuation can be considered.

5.7 Serotonin Syndrome Serotonin syndrome, a potentially life-threatening condition, may occur with FINTEPLA, particularly with concomitant administration of FINTEPLA with other serotonergic drugs, including, but not limited to, selective serotonin-norepinephrine reuptake inhibitors (SNRIs), selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), bupropion, triptans, dietary supplements (e.g., St. John&apos;s Wort, tryptophan), drugs that impair metabolism of serotonin (including monoamine oxidase inhibitors [MAOIs], which are contraindicated with FINTEPLA <span class="opacity-50 text-xs">[see Contraindications (4) ]</span>, dextromethorphan, lithium, tramadol, and antipsychotics with serotonergic agonist activity. Patients should be monitored for the emergence of signs and symptoms of serotonin syndrome, which include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular signs (e.g., hyperreflexia, incoordination), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). If serotonin syndrome is suspected, treatment with FINTEPLA should be stopped immediately and symptomatic treatment should be started.

5.8 Increase in Blood Pressure FINTEPLA can cause an increase in blood pressure <span class="opacity-50 text-xs">[see Adverse Reactions (6.1) ]</span>. Rare cases of significant elevation in blood pressure, including hypertensive crisis, has been reported in adult patients treated with fenfluramine, including patients without a history of hypertension. In clinical trials of up to 3 years in duration, no pediatric or adult patient receiving FINTEPLA developed a hypertensive crisis. Monitor blood pressure in patients treated with FINTEPLA.

5.9 Glaucoma Fenfluramine can cause mydriasis and can precipitate angle closure glaucoma. Consider discontinuing treatment with FINTEPLA in patients with acute decreases in visual acuity or ocular pain.