Novartis Highlights Kisqali’s Superiority Over Pfizer’s Ibrance with Nearly 5-Year Median Overall Survival in Metastatic Breast Cancer

Compiled by Fan Dongdong

Previously, Novartis had confirmed that Kisqali (ribociclib) in combination with endocrine therapy could help premenopausal patients with HR-positive, HER2-negative advanced breast cancer live longer. Recently, according to the latest results released by the company, the median overall survival (OS) of Kisqali for treating patients with metastatic breast cancer can reach nearly 5 years.

According to the Phase 3 data from the MONALEESA-7 trial presented by Novartis at the San Antonio Breast Cancer Symposium (SABCS) annual meeting, Kisqali combined with endocrine therapy helped premenopausal and perimenopausal women with HR+/HER2− disease achieve a median overall survival of 58.7 months. In comparison, after 53.5 months of follow-up, the median overall survival for patients receiving endocrine therapy alone was 48 months (HR = 0.76 [95% CI: 0.61–0.96]). The trial results demonstrated that the Kisqali regimen reduced the risk of death by 24%.

Furthermore, patients receiving Kisqali in combination with endocrine therapy (HR = 0.69; 95% CI: 0.56–0.87) delayed the need for chemotherapy by more than 4 years (50.9 months), representing an approximately 31% prolongation in the time to subsequent chemotherapy. In comparison, the median overall survival after first-line chemotherapy was 50.9 months for patients treated with the Kisqali combination, versus 36.8 months for those receiving endocrine therapy alone.

Currently, Novartis has reported statistically significant overall survival benefits with Kisqali in premenopausal women in the Monaleesa-7 trial and in postmenopausal women in the Monaleesa-3 study. Another trial, Monaleesa-2, which is designed to evaluate the combination of Kisqali with the endocrine therapy letrozole in previously untreated patients, is expected to report overall survival data in the second half of 2021.

Jeff Legos, Head of Oncology Drug Development at Novartis, specifically highlighted the efficacy comparison between Novartis’ Kisqali and its competitor Pfizer’s Ibrance. He noted that a retrospective analysis of the PALOMA-2 trial conducted three years ago found that Pfizer’s market-leading CDK4/6 inhibitor, Ibrance, did not provide benefit to the corresponding breast cancer patients.

Novartis has consistently attributed the superior efficacy of Kisqali compared to Ibrance to the greater tumor inhibitory effect of CDK4 inhibition relative to CDK6. Legos explained that although CDK4 is more widely expressed in breast cancer cells, CDK6 is more highly expressed in myeloma. Furthermore, CDK4 plays a more significant role in cell proliferation and growth.

In fact, Ibrance has previously encountered frequent setbacks in several clinical trials for HR+/HER2- breast cancer. For instance, the Paloma-3 trial demonstrated that adding Ibrance to endocrine therapy in patients with metastatic disease did not effectively prolong overall survival. Moreover, Ibrance failed to extend survival or delay disease recurrence in patients with early-stage breast cancer. The drug also did not demonstrate therapeutic benefits in broader populations of breast cancer patients or in high-risk subgroups within these trials.

Reference Sources:

1.Novartis touts Kisqali's 5-year breast cancer survival, advantage over Pfizer's Ibrance

2.Novartis Kisqali® demonstrates nearly five years median overall survival in metastatic breast cancer