CDK4/6 inhibitors in MBC

 MONARCH 2- Abema with fulvestrant in pre, peri and post menopausal women showed OS benefit ( front line, after progression on adjuvant AI).

MONALEESA trials- Ribociclib OS benefit in the above groups.

Package insert

Ribociclib:

Dose 600 mg daily 3 weeks on, 1week off ( 28 day cycle)

Baseline:

1. Electrolytes and EKG at baseline, C1D14 and C2 D1. Then electrolytes day 1 of first 6 cycles. EKG periodically and as clinically indicated. QTc prolonged 4%. Check CBC q 2weeks for first 2 cycles, then at the beginning of each cycle.

2. Monitor of symptoms of hepatotoxicity 14%

3. Monitor for ILD symptoms ( 0.6%).

4. Check med list for any drugs that may interact or prolong Qtc

5. Cannot use Ribo with tamoxifen due to QTc prolongation.