Ami N Shah 1 , Lisa Flaum 2 , Irene Helenowski 2 , Cesar A Santa-Maria 3 , Sarika Jain 2 , Alfred Rademaker 2 , Valerie Nelson 2 , Dean Tsarwhas 2 , Massimo Cristofanilli 2 , William Gradishar 2 . Show Affiliations »
Abstract
BACKGROUND: Response rates to single agent immune checkpoint blockade in unselected pretreated HER2-negative metastatic breast cancer (MBC) are low. However, they may be augmented when combined with chemotherapy. METHODS: We conducted a single-arm, phase II study of patients with triple negative (TN) or hormone receptor-positive endocrine-refractory (HR+) MBC who were candidates for capecitabine. Patients were treated with pembrolizumab 200 mg intravenously day 1 and capecitabine 1000 mg/m2 by mouth twice daily on days 1-14 of a 21-day cycle. The primary end point was median progression-free survival (mPFS) compared with historic controls and secondary end points were overall response rate (ORR), safety and tolerability. The study had 80% power to detect a 2-month improvement in mPFS with the addition of pembrolizumab over historic controls treated with capecitabine alone. RESULTS: Thirty patients, 16 TN and 14 HR+ MBC, were enrolled from 2017 to 2018. Patients had a median age of 51 years and received a median of 1 (range 0-6) prior lines of therapy for MBC. Of 29 evaluable patients, the mPFS was 4.0 (95% CI 2.0 to 6.4) months and was not significantly longer than historic controls of 3 months. The median overall survival was 15.4 (95% CI 8.2 to 20.3) months. The ORR was 14% (n=4), stable disease (SD) was 41% (n=12) and clinical benefit rate (CBR=partial response+SD>6 months) was 28% (n=8). The ORR and CBR were not significantly different between disease subtypes (ORR 13% and 14%, CBR 25% and 29% for TN and HR+, respectively). The 1-year PFS rate was 20.7% and three patients have ongoing responses. The most common adverse events were low grade and consistent with those seen in MBC patients receiving capecitabine, including hand-foot syndrome, gastrointestinal symptoms, fatigue and cytopenias. Toxicities at least possibly from pembrolizumab included grade 3 or 4 liver test abnormalities (7%), rash (7%) and diarrhea (3%), as well as grade 5 hepatic failure in a patient with liver metastases. CONCLUSIONS: Compared with historical controls, pembrolizumab with capecitabine did not improve PFS in this biomarker unselected, pretreated cohort. However, some patients had prolonged disease control. TRIAL REGISTRATION NUMBER: NCT03044730. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
BACKGROUND: Response rates to single agent immune checkpoint blockade in unselected pretreated HER2 -negative metastatic breast cancer (MBC) are low. However, they may be augmented when combined with chemotherapy. METHODS: We conducted a single-arm, phase II study of patients with triple negative (TN) or hormone receptor -positive endocrine-refractory (HR+) MBC who were candidates for capecitabine . Patients were treated with pembrolizumab 200 mg intravenously day 1 and capecitabine 1000 mg/m2 by mouth twice daily on days 1-14 of a 21-day cycle. The primary end point was median progression-free survival (mPFS) compared with historic controls and secondary end points were overall response rate (ORR), safety and tolerability. The study had 80% power to detect a 2-month improvement in mPFS with the addition of pembrolizumab over historic controls treated with capecitabine alone. RESULTS: Thirty patients , 16 TN and 14 HR+ MBC, were enrolled from 2017 to 2018. Patients had a median age of 51 years and received a median of 1 (range 0-6) prior lines of therapy for MBC. Of 29 evaluable patients , the mPFS was 4.0 (95% CI 2.0 to 6.4) months and was not significantly longer than historic controls of 3 months. The median overall survival was 15.4 (95% CI 8.2 to 20.3) months. The ORR was 14% (n=4), stable disease (SD ) was 41% (n=12) and clinical benefit rate (CBR=partial response+SD >6 months) was 28% (n=8). The ORR and CBR were not significantly different between disease subtypes (ORR 13% and 14%, CBR 25% and 29% for TN and HR+, respectively). The 1-year PFS rate was 20.7% and three patients have ongoing responses. The most common adverse events were low grade and consistent with those seen in MBC patients receiving capecitabine , including hand-foot syndrome , gastrointestinal symptoms , fatigue and cytopenias . Toxicities at least possibly from pembrolizumab included grade 3 or 4 liver test abnormalities (7%), rash (7%) and diarrhea (3%), as well as grade 5 hepatic failure in a patient with liver metastases . CONCLUSIONS: Compared with historical controls, pembrolizumab with capecitabine did not improve PFS in this biomarker unselected, pretreated cohort. However, some patients had prolonged disease control. TRIAL REGISTRATION NUMBER: NCT03044730. © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
Entities: Chemical
Disease
Gene
Mutation
Species
Keywords:
breast neoplasms; immunology; oncology; programmed cell death 1 receptor
Year: 2020
PMID: 32060053 DOI: 10.1136/jitc-2019-000173
Source DB: PubMed Journal: J Immunother Cancer ISSN: 2051-1426 Impact factor: 13.751