Cancer Focused Ambrx Biopharma Stock Trading Lower Today - Here's Why

Ambrx Biopharma Inc AMAM announced that two abstracts detailing updated safety and efficacy data from the ongoing Phase 1/2 trial, APEX-01, evaluating ARX517 for metastatic castration-resistant prostate cancer (mCRPC) were made available as part of the 2023 European Society of Medical Oncology Congress 2023 meeting.

APEX-01 opened for enrollment in July 2021.

Also Read: Unique ADC Constructs Boost Ambrx Biopharma's Profile: Analyst Sees Optimistic Outlook.

Data from the APEX-01 First-in-human Phase 1/2 study of ARX517 in mCRPC shows that 7 out of 9 patients experienced a ≥50% prostate-specific antigen (PSA) reduction.

5 out of 5 patients experienced a ≥50% ctDNA reduction.

In 24 dose escalation patients treated from 0.32 mg/kg (Cohort 1) to 2.88 mg/kg (Cohort 8), ARX517 was well-tolerated at all doses.

ARX517 demonstrates notable stability and pharmacokinetic (PK) profile in the ARX517 Phase 1/2 clinical trial (APEX-01).

ARX517 exhibited virtually overlapping total antibody and ADC PK concentration-time curves at all tested dose levels, indicating strong ADC stability with minimal premature payload release.

Price Action: AMAM shares are down 30.4% at $9.78 on the last check Monday.