Posology : מינונים

5     Dosage and administration
5.1   Patient Selection
Select patients for treatment of ER-positive, HER2-negative advanced or metastatic breast cancer with ORSERDU based on the presence of ESR1 mutation(s) in plasma specimen using an approved test [see Therapeutic Indication (4) and Clinical Studies (15)].
5.2   Recommended Dosage
The recommended dosage of ORSERDU is 345 mg taken orally with food once daily until disease progression or unacceptable toxicity occurs.
Take ORSERDU at approximately the same time each day. Take with food to reduce nausea and vomiting [see Adverse Reactions (8.1)].
Swallow ORSERDU tablet(s) whole. Do not chew, crush, or split prior to swallowing. Do not take any ORSERDU tablets that are broken, cracked, or that look damaged.
If a dose is missed for more than 6 hours or vomiting occurs, skip the dose and take the next dose the following day at its regularly scheduled time.
5.3     Dosage Modifications for Adverse Reactions
The recommended dose reduction levels for adverse reactions are listed in Table 1: Table 1: ORSERDU Dose Reduction Levels for Adverse Reactions
Dose Reduction         Dosage                      Number and Strength of Tablets
First-dose reduction             258 mg once daily                    Three 86 mg tablets Second-dose reduction            172 mg once daily1                   Two 86 mg tablets 1
If further dose reduction below 172 mg once daily is required, permanently discontinue ORSERDU.

Recommended dosage modifications of ORSERDU for adverse reactions are provided in Table 2 [see Adverse Reactions (8.1)].
Table 2: ORSERDU Dosage Modification Guidelines for Adverse Reactions Severity                                    Dosage Modification
Grade 1                                     Continue ORSERDU at current dose level.
Grade 2                                     Consider interruption of ORSERDU until recovery to Grade ≤ 1 or baseline. Then resume
ORSERDU at the same dose level.
Grade 3                                     Interrupt ORSERDU until recovery to Grade ≤ 1 or baseline. Then resume ORSERDU at the next lower dose level.

If the Grade 3 toxicity recurs, interrupt ORSERDU until recovery to Grade ≤ 1 or baseline. Then resume ORSERDU reduced by another dose level.
Grade 4                                                         Interrupt ORSERDU until recovery to Grade ≤ 1 or baseline. Then resume ORSERDU reduced by one dose level.

If a Grade 4 or intolerable adverse reaction recurs, permanently discontinue ORSERDU.

5.4     Dosage Modifications for Use with Concomitant CYP3A4 Inducers and Inhibitors Avoid concomitant use of ORSERDU with strong or moderate CYP3A4 inducers and inhibitors including grapefruit or grapefruit juice [see Drug Interactions (9.1)].
5.5     Dosage Modifications for Hepatic Impairment
Avoid use of ORSERDU in patients with severe hepatic impairment (Child-Pugh C). Reduce the ORSERDU dosage to 258 mg once daily for patients with moderate hepatic impairment (Child-Pugh B). No dosage adjustment is recommended for patients with mild hepatic impairment (Child-Pugh A) [see Clinical Pharmacology (13.3)].