- Ribociclib in combination with letrozole is associated with a 12-week PFS rate of:
- 50% in patients with relapsed estrogen receptor-positive (ER+) ovarian cancer.
- 55% in patients with relapsed ER+ endometrial cancer.
- The PFS rate was higher in patients with ER+ recurrent low-grade serous ovarian cancer (LGSOC).
Why this matters
- These findings, together with the low toxicity of the drug combination, make ribociclib and letrozole in patients with LGSOC a promising treatment, pending confirmatory randomized studies.
- Phase 2 trial of 40 patients with measurable, relapsed ER+ ovarian cancer (n=20) or endometrial cancer (n=20) were treated with ribociclib plus letrozole.
- Funding: Novartis; Mayo Clinic Cancer Center.
- In patients with endometrial and ovarian cancer, respectively:
- 12-week PFS rate was 55% and 50%.
- Median PFS was 5.4 (95% CI, 3.1-11.8) and 2.8 (95% CI, 2.6-9.1) months.
- 24-week PFS rate was 35% and 20%.
- In subset analysis, PFS ≥24 weeks was reported in:
- 100% of patients with LGSOC.
- 45.5% of patients with grade 1 or 2 endometrioid endometrial cancer.
- Patient-derived xenografts were successfully engrafted in 45% of patients.
- Grade ≥3 adverse event rate was 60%.
- Small size.