warnings and cautions
5 WARNINGS AND PRECAUTIONS QTc Interval Prolongation : Monitor electrocardiograms (ECGs) and electrolytes prior to initiation of treatment with VEPPANU. Correct hypokalemia and hypomagnesemia prior to and during treatment. Repeat ECGs as clinically indicated. Withhold, reduce dose, or permanently discontinue VEPPANU based on severity. ( 5.1 ) Embryo-Fetal Toxicity : VEPPANU can cause fetal harm. Advise patients of the potential risk to a fetus and to use effective contraception. ( 5.2 , 8.1 , 8.3 ) 5.1 QTc Interval Prolongation VEPPANU can cause QT (QTc) interval prolongation [see Clinical Pharmacology ( 12.2 )] . In VERITAC-2, QTc interval prolongation was reported in 10% of patients; Grade 3 occurred in 1.6% of patients. The heart-rate corrected QTc interval using Fridericia's method was greater than 500 msec in 1.6% of patients, and the increase from baseline QTc was greater than 60 msec in 2.6% of patients. VEPPANU dose reduction was required for 0.3% of patients due to QTc interval prolongation [see Adverse Reactions ( 6.1 )] . Correct electrolyte abnormalities, including hypokalemia and hypomagnesemia, prior to and during treatment with VEPPANU. Perform an ECG prior to initiation of treatment with VEPPANU, and do not initiate VEPPANU in patients with QTc > 470 msec. Repeat ECG approximately 4 weeks after initiating treatment and as clinically indicated. In patients with congenital long QTc syndrome, congestive heart failure, electrolyte abnormalities, or those who are taking medications known to prolong the QTc interval, additional ECG monitoring may be necessary. Avoid concomitant use of VEPPANU with strong CYP3A inhibitors or drugs known to prolong the QTc interval. Reduce VEPPANU dose when concomitant use with strong CYP3A inhibitors cannot be avoided [see Dosage and Administration ( 2.4 ), Drug Interactions ( 7.1 , 7.3 ), and Clinical Pharmacology ( 12.2 )] . If concomitant use with other QTc-prolonging agents cannot be avoided, increase the frequency of ECG monitoring. Withhold, reduce dose, or permanently discontinue based on severity [see Dosage and Administration ( 2.3 )] . 5.2 Embryo-Fetal Toxicity Based on findings from animal studies and its mechanism of action, VEPPANU can cause fetal harm when administered to a pregnant woman. In an animal reproduction study, oral administration of vepdegestrant to pregnant rats during the period of organogenesis resulted in adverse developmental outcomes, including embryo-fetal mortality and structural abnormalities, at maternal exposures below the recommended dose based on area under the curve (AUC). Advise pregnant women and females of reproductive potential of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with VEPPANU and for 2 weeks after the last dose. Advise male patients with female partners of reproductive potential to use effective contraception during treatment with VEPPANU and for 2 weeks after the last dose [see Use in Specific Populations ( 8.1 , 8.3 ) and Clinical Pharmacology ( 12.1 )] .