A Phase 2 Trial of Ribociclib (LEE011) and Letrozole in ER Positive Relapsed Ovarian Cancer, Fallopian Tube Cancer, Primary Peritoneal Carcinomas, and Endometrial Cancers.

Trial ID #	NCT02657928
Phase	II
Drug Class	Hormonal Therapy: Aromatase
Drug Name	Letrozole
Alternate Drug Names	Femara
Drugs in Trial	Letrozole, Ribociclib
Eligible Participant	Recurrent ER+ ovarian cancer
Patients Enrolled	20, median 3 prior therapies (0-6); 17 HGS, 3 HGS; 7-Pt-S, 12 Pt-R
Therapy Setting	Recurrence
Study Design	Open-Label, Non-randomized
Endpoints	ORR, DCR, PFS, OS, evaluated per RECIST
Biomarkers	ER+
Efficacy	ORR: 15% (3PR - 3 LGS) ORR (HGS): 0% PFS ≥ 23 weeks: 25% (3PR, 2SD) - 3/3 LGS still on treatment for 28+, 24+ and 19+ months PFS ≥ 23 weeks (HGS): 12% (2SD) PFS (12 weeks): 50% PFS: 2.8 months OS: 18.9 months
Clinically Significant Adverse Events	Serious AE: Grade 3-4 AE: Leukopenia (17.5%), neutropenia (15%), lymphopenia (10%)
Conclusion	Letrozole+ribociclib is active in ER+ ovarian cancer with 25% achieving PFS for 23 weeks or longer, but greatest benefit is seen in low grade serous (LGS) ovarian cancer
Reference	Colon-Otero G et al. Results of a phase 2 trial of ribociclib and letrozole in patients with either relapsed estrogen receptor (ER)-positive ovarian cancers or relapsed ER-positive endometrial cancers. J Clin Oncol (2019) 37 (suppl; abstr 5510) https://ascopubs.org/doi/abs/10.1200/JCO.2019.37.15_suppl.5510 Colon-Otero G et al. Slide from presentation https://www.clearityfoundation.org/wp-content/uploads/2020/07/Ribociclib-and-Letrozole-ASCO-2019-slide.pdf