The effectiveness and safety of eribulin therapy in HR-positive HER2-negative metastatic breast cancer post-CDK4/6 inhibitor therapy in Russian clinical practice

• Published in: Journal of clinical oncology Vol. 39; no. 15_suppl; p. e13035
• Main Authors: Kolyadina, Irina Vladimirovna, Bolotina, Larisa, Zhukova, Lyudmila, Vladimirova, Liubov Yu, Sultanbaev, Alexander, Karabina, Elena, Ganshina, Inna, Ovchinnikova, Elena, Antonova, Galina, Volkonsky, Mikhail, Kolokolov, James, Zueva, Elena, Akopyan, I, Fadeeva, Natalia, Evstigneeva, Irina, Orlova, Svetlana, Vasilevskaya, Anna, Shalaeva, Oxana, Shirokova, Oxana
• Format: Journal Article
• Language: English
• Published: 20.05.2021
• DOI: 10.1200/JCO.2021.39.15_suppl.e13035
• ISSN: 0732-183X

Abstract only e13035 Background: EMPOWER trial demonstrated the benefit of eribulin administrated post CD4/6i in patients (pts) with HR+ HER2-negative (HR+HER2-) metastatic breast cancer (MBC). There are several important limitations to this trial: > 60% of pts were stage IV at the time of treatment initiation, eribulin used in late lines (2L only in 30% pts) and follow-up data were immature. Current study aimed to provide additional data on the real-world effectiveness and safety of eribulin monotherapy in this setting. Methods: Observation study of eribulin monotherapy in standard regimen enrolled 54 pts (median age 56; range 29-79 years) with HR+ HER2- MBC received at least one dose of eribulin post CDK 4/6i in metastatic settings; 24% pts had de novo metastatic BC, 76% - recurrent BC; 77% received palbociclib, 21% ribociclib, 2% both drugs; 49% pts received CDK4/6i with fulvestrant and 51% with AI. CDK4/6i was used: 49% pts in 1L, 36% in 2L, 16% in 3L. Median DOR of CDK4/6i treatment was 9.07 months (range 2-38). 94% pts received anthracyclines and taxanes, eribulin was used in 2L in 60%, 30% in 3L, 8% in 4L, 2% in 5L. The most common sites of metastases (Mts) were bones (78%), liver (73%), lung (56%) and brain (8%); visceral Mts were seen in 90% pts. Median follow-up – 11,5 months (range 3-36). Results: Median cycles of eribulin therapy was 10,5 (range 1-44); objective response rate was seen in 24%, stabilization - 67%, progression - in 9%. Median PFS was 10.0 months, there were no significant differences in the different subgroups (visceral/no visceral; recurrent/de novo BC; age; CDK4/6i as 1L vs 2L, fulvestrant vs AI), p > 0,05. Median PFS was higher in pts with lung Mts vs non-lung (24 vs 9,1 months, p = 0.056). Most common AEs all grades were neutropenia (26%), anemia (9%), asthenia (9%), polyneuropathy (11.1%). AE did not affect the effectiveness of eribulin (p = 0.648). Dose reduction was in 19% pts and did not affect the effectiveness of eribulin (p = 0.612). At median follow-up of 11.5 months, 92.5% of patients still alive. Conclusions: As post-CDK4/6i therapy, eribulin in HR+HER2- MBC pts was effective and well tolerated, regardless of age, line of CDK4/6, CDK 4/6i combination partner. Patients with metastasis to the lung have better mPFS. Results in this real-world population of pts with HR+HER2- MBC were consistent with the EMPOWER study, and support administration of eribulin in 2-3 lines as an effective option for post-CD4/6i pts.