Treatment with KORSERDU should be initiated by a physician experienced in the use of anticancer therapies.
Patients with ER-positive, HER2-negative advanced breast cancer should be selected for treatment with KORSERDU based on the presence of an activating ESR1 mutation in plasma specimens, using a CE marked in vitro diagnostic (IVD) with the corresponding intended purpose. If the CE-marked IVD is not available, the presence of an activating ESR1 mutation in plasma specimens should be assessed by an alternative validated test.
Posology
The recommended dose is 345 mg (one 345 mg film-coated tablet), once daily.
The maximum recommended daily dose of KORSERDU is 345 mg.
Treatment should continue as long as clinical benefit is observed or until unacceptable toxicity occurs.
Missed dose
If a dose is missed, it can be taken immediately within 6 hours after the time it is usually taken. After more than 6 hours, the dose should be skipped for that day. On the next day, KORSERDU should be taken at the usual time.
Vomiting
If the patient vomits after taking the KORSERDU dose, the patient should not take an additional dose on that day and should resume the usual dosing schedule the next day at the usual time.
Dose modifications
The recommended elacestrant dose modifications for patients with adverse reactions (see section 4.8) are provided in Tables 1 and 2:
Table 1: KORSERDU dose reduction for adverse reactions
| KORSERDU dose level | Dose and schedule | Number and strength of tablets |
| Dose reduction | 258 mg once daily | Three 86 mg tablets |
If further dose reduction below 258 mg once daily is required, discontinue KORSERDU.
Table 2: KORSERDU dose modification guidelines for adverse reactions
| Severity | Dose modification |
| Grade 2 | Consider interruption of KORSERDU until recovery to Grade ≤ 1 or baseline. Then resume KORSERDU at the same dose level. |
| Grade 3 | KORSERDU should be interrupted until recovery to Grade ≤ 1 or baseline. The dose should be reduced to 258 mg once daily when resuming therapy. If the Grade 3 toxicity recurs, KORSERDU should be interrupted until recovery to Grade ≤ 1 or baseline. The reduced dose of 258 mg may be resumed at the discretion of the treating physician the patient is benefiting from treatment. If a Grade 3 or intolerable adverse reaction recurs, KORSERDU should be permanently discontinued. |
| Grade 4 | Interrupt KORSERDU until recovery to Grade ≤ 1 or baseline. The dose should be reduced to 258 mg once daily when resuming therapy. If a Grade 4 or intolerable adverse reaction recurs, permanently discontinue KORSERDU. |
Use of KORSERDU with CYP3A4 inhibitors
Concomitant use of strong or moderate CYP3A4 inhibitors should be avoided and an alternative concomitant medicinal product with no or minimal potential to inhibit CYP3A4 should be considered.
If a strong CYP3A4 inhibitor must be used, the elacestrant dose should be reduced to 86 mg once daily with careful monitoring of tolerability. If a moderate CYP3A4 inhibitor must be used, the elacestrant dose should be reduced to 172 mg once daily with careful monitoring of tolerability. Subsequent dose reduction to 86 mg once daily may be considered with moderate CYP3A4 inhibitors based on tolerability.
If the CYP3A4 inhibitor is discontinued, the elacestrant dose should be increased to the dose used prior to the initiation of the CYP3A4 inhibitor (after 5 half-lives of the CYP3A4 inhibitor) (see sections 4.4, 4.5 and 5.2).
No dose adjustments are required for coadministration of KORSERDU with mild CYP3A4 inhibitors (see section 4.5).
Use of KORSERDU with CYP3A4 inducers
Concomitant use of strong or moderate CYP3A4 inducers should be avoided and an alternative concomitant medicinal product with no or minimal potential to induce CYP3A4 should be considered.
If a strong or moderate CYP3A4 inducer must be used for a short duration of time (i.e. ≤ 3 days) or intermittently (i.e. treatment periods ≤ 3 days separated by at least 2 weeks or 1 week + 5 half-lives of the CYP3A4 inducer, whichever is longer), continue elacestrant without increasing the dose.
No dose adjustments are required for coadministration of KORSERDU with mild CYP3A4 inducers (see sections 4.4, 4.5 and 5.2).
Special populations
Elderly
No dose adjustment is required on the basis of patient age. Limited data are available in patients ≥ 75 years of age (see section 5.2).
Hepatic impairment
No dose adjustment is recommended for patients with mild hepatic impairment (Child-Pugh A). In patients with moderate hepatic impairment (Child-Pugh B), KORSERDU dose should be reduced to 258 mg. Elacestrant has not been studied in patients with severe hepatic impairment (Child-Pugh C), therefore no dose recommendation can be made for patients with severe hepatic impairment (see section 4.4).
Renal impairment
No dose adjustment in subjects with renal impairment is necessary. Elacestrant has not been studied in patients with severe renal impairment, therefore no dose recommendation can be made for patients with severe renal impairment (see section 5.2).
Paediatric population
The safety and efficacy of KORSERDU in children from birth to 18 years of age has not been established. No data are available.
Method of administration
KORSERDU is for oral use.
The tablets should be swallowed whole. They should not be chewed, crushed or split prior to swallowing. Patients should take their dose of KORSERDU at approximately the same time each day. KORSERDU should be administered with a light meal. Administration with food may also reduce nausea and vomiting (see section 5.2).