Department of Oncology, Zhejiang Cancer Hospital, Hangzhou, China
Xiaojia Wang , Keun Seok Lee , Xiaohua Zeng , Tao Sun , Young-Hyuck Im , Huiping Li , Kun Wang , Huiyan Li , Ping Zhou , Yuanyuan Bao , Zefei Jiang
Background: Despite HER2-targeted agents improving outcomes in HER2-positive (+) BC, some pts develop resistance, relapse, or do not respond to current 1L therapies. Zani, also known as ZW25, is a novel HER2-targeted bispecific antibody that binds to two distinct extracellular domains of HER2. Preliminary results from this Phase Ib/II trial (NCT04276493) showed that zani plus docetaxel had a manageable safety profile and demonstrated promising antitumor activity in pts with advanced HER2+ BC; here we present the updated data following enrollment completion. Methods: Cohort 1 of this open-label study is evaluating zani in combination with docetaxel as a 1L therapy in adult females with advanced HER2+ BC who may have received prior neoadjuvant/adjuvant therapy. Cohort 1a pts received zani 30 mg/kg intravenously (IV), Cohort 1b pts received zani 1800 mg IV, both with docetaxel 75 mg/m2 IV every 3 weeks. The primary endpoints were safety and investigator (INV)-assessed objective response rate (ORR) per RECIST v1.1. Secondary endpoints included INV-assessed duration of response (DoR) and disease control rate (DCR). Results: As of Nov 22, 2022, 37 pts(median age 55.0 years [range: 33-80]) were assigned to Cohort 1a (n=10) or 1b (n=27). Median study follow-up was 15.5 months (range: 1.1-29.3); patients received a median of 13 treatment cycles (range 1-37) and 18 (48.6%) pts remained on treatment. Of the 33-efficacy evaluable (EE) pts, confirmed ORR was 90.9% (95% confidence interval [CI]: 75.7, 98.1). Efficacy data are summarized in the table. In total, 36 (97.3%) pts experienced ≥1 treatment-related adverse event (TRAE); 25 (67.6%) pts experienced ≥grade 3 TRAEs. The most common ≥grade 3 TRAEs were decreased neutrophil count, experienced by 18 (48.6%) pts, and decreased white blood cell count, experienced by 7 (18.9%) pts. Serious TRAEs occurred in 6 (16.2%) pts; no TRAEs led to death. Conclusions: Zani combined with docetaxel demonstrated promising antitumor activity as 1L therapy for advanced HER2+ BC, with a manageable safety profile. Clinical trial information: NCT04276493.
Cohort 1a (n=8) | Cohort 1b (n=25) | Total (n=33) | |
---|---|---|---|
Confirmed best overall response, n (%) | |||
Complete response | 1 (12.5) | 1 (4.0) | 2 (6.1) |
Partial response | 7 (87.5) | 21 (84.0) | 28 (84.8) |
Stable disease | 0 (0.0) | 2 (8.0) | 2 (6.1) |
Progressive disease | 0 (0.0) | 1 (4.0) | 1 (3.0) |
Confirmed ORR, n (%) 95% CI | 8 (100) 63.1, 100 | 22 (88.0) 68.8, 97.5 | 30 (90.9) 75.7, 98.1 |
Confirmed DCR, n (%) 95% CI | 8 (100) 63.1, 100 | 24 (96.0) 79.6, 99.9 | 32 (97.0) 84.2, 99.9 |
Median DoR, months (95% CI) | 12.4 5.5, NE | NE 12.1, NE | NE 12.1, NE |
Confirmed DoR, range† | 3.5†-23.5† | 4.3†-16.5† | 3.5†-23.5† |
*Four pts without any postbaseline tumor assessments were excluded from the EE analysis set.
Data cut off: November 22, 2022.
†Censored.
Disclaimer
This material on this page is ©2024 American Society of Clinical Oncology, all rights reserved. Licensing available upon request. For more information, please contact licensing@asco.org
Abstract Disclosures
2023 ASCO Annual Meeting
First Author: Xiaojia Wang
2022 ASCO Annual Meeting
First Author: Keun-Seok Lee
2021 ASCO Annual Meeting
First Author: Keun Wook Lee
2020 ASCO Virtual Scientific Program
First Author: Do-Youn Oh