Ambrx Biopharma Stock (AMAM): Why The Price Jumped Today

By Amit Chowdhry ● Dec 9, 2021
  • The stock price of Ambrx Biopharma Inc (NYSE: AMAM) increased by over 29% during intraday trading today. This is why it happened.

The stock price of Ambrx Biopharma Inc (NYSE: AMAM) – a clinical stage biopharmaceutical company using an expanded genetic code technology platform to discover and develop Engineered Precision Biologics (EPBs) – increased by over 29% during intraday trading today. Investors are responding positively to Ambrx Biopharma announcing that NovoCodex Pharmaceuticals Ltd. (NovoCodex), Ambrx’s partner in China, presented positive safety and efficacy data from its ongoing ACE-Breast-01 Phase 1 clinical study of ARX788 at the San Antonio Breast Cancer Symposium (SABCS).

ACE-Breast-01 is a Phase 1 clinical study of ARX788 in HER2-positive metastatic breast cancer patients whose disease is resistant/refractory to HER2 targeted agents including trastuzumab, ADCs (antibody drug conjugates), TKIs (tyrosine kinase inhibitors) and bispecific antibodies. And the updated data, presented during a spotlight poster session (PD8-04), demonstrates ARX788’s robust anti-tumor activity.

Study Highlights

ARX788 at 1.5 mg/kg Q3W demonstrated robust treatment effect as illustrated by objective response rate (ORR) in 29 patients in all prior anti-HER2 treatments groups:

Prior Anti-HER2 Therapy

Trastuzumab containing regimens — Confirmed ORR: 19/29 (66%)

HER2 ADC regimens (T-DM1, DX126-262, A166, BAT8001, HS630) — Confirmed ORR: 4/5 (80%)

HER2 TKI regimens (lapatinib, pyrotinib, neratinib, AST-1306, Hemay-022) — Confirmed ORR: 15/23 (65%)

Both HER2 ADC and HER2 TKI regimens — Confirmed ORR: 3/4 (75%)

Bispecific antibody containing regimens (KN026 and M802) — Confirmed ORR: 3/4 (75%)

The Phase 1 clinical study being conducted by the company’s partner NovoCodex is a dose-escalation study designed to evaluate the safety and anti-tumor activity of ARX788 administered every 3 weeks in heavily pretreated patients with HER2-positive metastatic breast cancer. And the 29 evaluable patients in the 1.5 mg/kg Q3W dose cohort who participated in the study were heavily pretreated with and had failed, a median of seven prior lines of therapy (median of six for the 69 patients in all cohorts) in the advanced disease setting.

Plus Ambrx presented a poster on ACE-Breast-03 in a SABCS ongoing trial poster session (OT1-02-02). And the poster details ARX788 in its ongoing global ACE-Breast-03 Phase 2 clinical study in patients with HER2-positive metastatic breast cancer whose disease is resistant or refractory to T-DM1, and/or T-DXd, and/or tucatinib-containing regimens. This study is currently enrolling up to 200 patients and will assess the efficacy, safety, and pharmacokinetics of ARX788, with a confirmed objective response rate as the primary endpoint.


“As the ACE-Breast-01 data for ARX788 continues to develop, we are encouraged by the ADC’s anti-tumor activity and safety profile. ARX788’s ability to continually deliver anti-cancer activity in patients with prior anti-HER2 therapies including ADCs, TKIs and bispecifics, truly highlights the potential of our drug candidate. I look forward to working with NovoCodex to realize the full potential of ARX788.”

“Ambrx’s proprietary EuCODE technology enables ARX788 to maximize the delivery efficiency of the therapeutic’s cytotoxic payload AS269 into HER2-expressing tumor cells. I am looking forward to our on-going global ACE-Breast-03 phase 2 study designed for patients with HER2-positive metastatic breast cancer whose disease is resistant or refractory to T-DM1, T-DXd, and tucatinib-containing regimens.”

— Feng Tian, Ph.D., Chairman of the Board, President and CEO of Ambrx

Disclaimer: This content is intended for informational purposes. Before making any investment, you should do your own analysis.