Add on Fovinaciclib to First-Line Hormone Therapy Improves Outcomes in breast cancer: Study

The researchers carried out a stringent phase 3 trial in a total of 63 specialized cancer centers in China. This study involved the enrollment of adult women within the ages of 18 and 75 between March 2, 2022, and June 28, 2023, in patients with confirmed evidence of having hormone receptor-positive, ERBB2-negative advanced breast cancer without any prior exposure to systemic treatment for their advanced condition. Qualified participants were assigned randomly in a 1:1 allocation ratio into the treatment arm receiving the drug or the control group receiving a matched placebo.

Patients from the treatment group were administered orally with 200 mg of the study drug (fovinaciclib) once daily on days 1 to 21 in combination with a common aromatase inhibitor (either letrozole 2.5 mg or anastrozole 1 mg) taken once daily on days 1 to 28 for 28-day cycles. The patients from the control group received the same aromatase inhibitor together with a placebo. Besides, any pre- or perimenopausal women participating in this research also received an intravenous dose of 3.6 mg goserelin on day one of each cycle.

Key findings:

• The multicenter trial was successful in randomizing 417 adults’ females to the study, thereby giving a median age at baseline of 57.0 years (age range: 32–84 years).
• The study subjects were equally divided with 208 patients randomly allocated to the active group containing the combination of fovinaciclib while 209 were in the placebo group.
• At the prespecified interim analysis, with median follow-up of 16.6 months (0.3-27.8 months), the median PFS was prolonged in the active treatment arm where it had not yet been reached but the median PFS of the placebo group stood at 20.2 months.
• The independent blinded central review showed that the hazard ratio between the two arms is 0.55 (95% confidence interval [CI]: 0.38-0.77) indicating a very high significance level of P < .001.
• Follow-up for overall survival beyond the interim cut-off point was still immature with only 40 deaths reported (9.6% of all subjects).
• The incidence of permanent treatment withdrawal because of treatment-emergent adverse events was minimal as it was only 1.4% in both treatment arms (3 patients each out of 208 and 209 patients in respective arms).

It can be concluded that the addition of Fovinaciclib to the first-line aromatase inhibitor resulted in PFS benefits and efficacy results as well as tolerable safety and no impact on the quality of life. Therefore, it is important to integrate Fovinaciclib in the initial treatment for cancer patients.

Reference:

Yuan P, Liu Y, Li W, et al. Fovinaciclib for First-Line Therapy of Advanced Breast Cancer: A Randomized Clinical Trial. JAMA Oncol. Published online June 01, 2026. doi:10.1001/jamaoncol.2026.1938