QT interval prolongation. KISQALI has been shown to prolong the QT interval in a concentration-dependent manner. Based on the observed QT prolongation during treatment, KISQALI may require...
KISQALI mechanism of action.
Percentages of CDK4/6 inhibition and impact on kinases outside of CDK4 and CDK6 are derived from in vitro results from a single biochemical assay at a single concentration.7 Similar inhibition of and selectivity for CDK4 and CDK6 has been demonstrated in other preclinical assays.8 Preclinical activity does not necessarily correlate with clinical outcomes.
CDK=cyclin-dependent kinase; ER=estrogen receptor; ET=endocrine therapy; G=gap phase; HER2-=human epidermal growth factor receptor 2-negative; HR+=hormone receptor-positive; M=mitotic phase; mBC=metastatic breast cancer; S=synthesis phase.
References: 1. Kisqali [prescribing information]. East Hanover, NJ: Novartis Pharmaceuticals Corp; 2017. 2. Hortobagyi GN, Stemmer SM, Burris HA, et al. Ribociclib as first-line therapy for HR-positive, advanced breast cancer. N Engl J Med. 2016;375(18):1738-1748. 3. O’Leary B, Finn RS, Turner NC. Treating cancer with selective CDK4/6 inhibitors. Nat Rev Clin Oncol. 2016;13(7):417-430. 4. Butt AJ, McNeil CM, Musgrove EA, Sutherland RL. Downstream targets of growth factor and oestrogen signalling and endocrine resistance: the potential roles of c-Myc, cyclin D1 and cyclin E. Endocrine Relat Cancer. 2005;12:S47-S59. 5. Osborne CK, Schiff R. Mechanisms of endocrine resistance in breast cancer. Annu Rev Med. 2011;62:233-247. 6. Finn RS, Aleshin A, Slamon DJ. Targeting the cyclin-dependent kinases (CDK) 4/6 in estrogen receptor-positive breast cancers. Breast Cancer Res. 2016;18(17):1-11. 7. Chen P, Lee N, Hu W, et al. Spectrum and degree of CDK drug interactions predicts clinical performance. Mol Cancer Ther. 2016;15(10):2273-2281;(suppl tables). 8. Tiedt R, Delach S, Kovats S, et al. Preclinical selectivity profile of the CDK4/6 inhibitor ribociclib compared with that of palbociclib and abemaciclib. Poster presented at: American Association for Cancer Research Annual Meeting; April 1-5, 2016; Washington, DC. Abstract 2346.
The KISQALI® (ribociclib) FEMARA® (letrozole) Co-Pack tablets is indicated as initial endocrine-based therapy for the treatment of pre/perimenopausal or postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer.
IMPORTANT SAFETY INFORMATION
QT interval prolongation. KISQALI and the KISQALI FEMARA Co-Pack have been shown to prolong the QT interval in a concentration-dependent manner. Based on the observed QT prolongation during treatment, KISQALI may require dose interruption, reduction, or discontinuation. Across clinical trials in patients with advanced or metastatic breast cancer treated with KISQALI in combination with an aromatase inhibitor or fulvestrant (“KISQALI treatment groups”), 14 of 1054 patients (1%) had >500 ms postbaseline QTcF value, and 59 of 1054 (6%) had a >60 ms increase from baseline in QTcF intervals. These ECG changes were reversible with dose interruption and most occurred within the first 4 weeks of treatment. No cases of torsades de pointes were reported. In MONALEESA-2, on the KISQALI + letrozole treatment arm, there was 1 (0.3%) sudden death in a patient with grade 3 hypokalemia and grade 2 QT prolongation. No cases of sudden death were reported in MONALEESA-7 or MONALEESA-3.
Assess ECG prior to initiation of treatment. Initiate treatment with KISQALI or the KISQALI FEMARA Co-Pack only in patients with QTcF values <450 ms. Repeat ECG at approximately Day 14 of the first cycle, at the beginning of the second cycle, and as clinically indicated. Monitor serum electrolytes (including potassium, calcium, phosphorus, and magnesium) prior to the initiation of treatment, at the beginning of each of the first 6 cycles, and as clinically indicated. Correct any abnormality before starting therapy with KISQALI or the KISQALI FEMARA Co-Pack therapy.
Avoid using KISQALI or the KISQALI FEMARA Co-Pack with drugs known to prolong the QT interval and/or strong CYP3A inhibitors, as this may lead to prolongation of the QTcF interval.
Increased QT Prolongation With Concomitant Use of Tamoxifen. KISQALI is not indicated for concomitant use with tamoxifen. In MONALEESA-7, the observed mean QTcF increase from baseline was ≥10 ms higher in the tamoxifen + placebo subgroup compared with the NSAI + placebo subgroup. In the placebo arm, an increase of >60 ms from baseline occurred in 6 of 90 patients (7%) receiving tamoxifen, and in no patients receiving an NSAI. An increase of >60 ms from baseline in the QTcF interval was observed in 14 of 87 (16%) patients in the KISQALI and tamoxifen combination and in 18 of 245 (7%) patients receiving KISQALI plus an NSAI.
Hepatobiliary toxicity. Across clinical trials in patients with advanced or metastatic breast cancer, increases in transaminases were observed. Across all trials, grade 3 or 4 increases in alanine aminotransferase (ALT) (10% vs 2%) and aspartate aminotransferase (AST) (7% vs 2%) were reported in the KISQALI and placebo arms, respectively.
Among the patients who had grade ≥3 ALT/AST elevation, the median time to onset was 85 days and median time to resolution to grade ≤2 was 22 days for the KISQALI treatment groups.
In MONALEESA-2 and MONALEESA-3, concurrent elevations in ALT or AST greater than 3 times the ULN and total bilirubin greater than 2 times the upper limit of normal (ULN), with normal alkaline phosphatase, in the absence of cholestasis occurred in 6 (1%) patients and all patients recovered after discontinuation of KISQALI. No cases occurred in MONALEESA-7.
Perform liver function tests (LFTs) before initiating therapy with KISQALI or the KISQALI FEMARA Co-Pack. Monitor LFTs every 2 weeks for the first 2 cycles, at the beginning of each of the subsequent 4 cycles, and as clinically indicated. Based on the severity of the transaminase elevations, KISQALI may require dose interruption, reduction, or discontinuation. Recommendations for patients who have elevated AST/ALT grade ≥3 at baseline have not been established.
Neutropenia. Across clinical trials in patients with advanced or metastatic breast cancer, neutropenia was the most frequently reported adverse reaction (AR) (74%), and a grade 3/4 decrease in neutrophil count (based on laboratory findings) was reported in 58% of patients in the KISQALI treatment groups. Among the patients who had grade 2, 3, or 4 neutropenia, the median time to grade ≥2 was 16 days. The median time to resolution of grade ≥3 (to normalization or grade <3) was 12 days in the KISQALI treatment groups. Febrile neutropenia was reported in 1% of patients in the KISQALI treatment groups. Treatment discontinuation due to neutropenia was 0.8%.
Perform complete blood count (CBC) before initiating therapy with KISQALI or the KISQALI FEMARA Co-Pack. Monitor CBC every 2 weeks for the first 2 cycles, at the beginning of each of the subsequent 4 cycles, and as clinically indicated. Based on the severity of the neutropenia, KISQALI may require dose interruption, reduction, or discontinuation.
Embryofetal toxicity. Based on findings from animal studies and the mechanism of action, KISQALI can cause fetal harm when administered to a pregnant woman. In animal reproduction studies, administration of KISQALI to pregnant rats and rabbits during organogenesis caused embryofetal toxicities at maternal exposures that were 0.6 and 1.5 times the human clinical exposure, respectively, based on area under the curve. Letrozole caused embryofetal toxicities in rats and rabbits at maternal exposures that were below the maximum recommended human dose (MHRD) on a milligrams per square meter basis. Advise pregnant women of the potential risk to a fetus. Advise women of reproductive potential to use effective contraception during therapy with KISQALI or the KISQALI FEMARA Co-Pack and for at least 3 weeks after the last dose.
Adverse reactions. Across clinical trials of patients with advanced or metastatic breast cancer, the most common ARs reported in the KISQALI treatment groups (pooled incidence ≥20%) were neutropenia (74% vs 5%), nausea (45% vs 27%), infections (41% vs 30%), fatigue (33% vs 30%), diarrhea (30% vs 22%), leukopenia (30% vs 3%), vomiting (27% vs 16%), alopecia (24% vs 12%), headache (24% vs 22%), constipation (24% vs 16%), rash (21% vs 9%), and cough (21% vs 16%). The most common grade 3/4 ARs (reported at a pooled frequency >5%) were neutropenia (59% vs 1%), leukopenia (16% vs 3%), abnormal LFTs (9% vs 2%), and lymphopenia (5% vs 1%).
Laboratory abnormalities. Across clinical trials of patients with advanced or metastatic breast cancer, the most common laboratory abnormalities reported in the KISQALI-containing arm vs placebo arm (all grades, pooled incidence ≥20% and ≥5% higher than placebo arm) were leukocyte count decrease (94% vs 30%), neutrophil count decrease (93% vs 25%), hemoglobin decrease (66% vs 38%), lymphocyte count decrease (61% vs 26%), AST increase (47% vs 38%), ALT increase (44% vs 36%), creatinine increase (38% vs 13%), and platelet count decrease (31% vs 9%). The most common grade 3/4 laboratory abnormalities (incidence >5%) were neutrophil count decrease (59% vs 2%), leukocyte count decrease (32% vs 1%), lymphocyte count decrease (15% vs 4%), ALT increase (10% vs 2%), and AST increase (7% vs 2%).