ALX Oncology Holdings has announced new data from a Phase 1b/2 trial suggesting its investigational CD47-inhibitor, evorpacept, could be a breakthrough for heavily pretreated patients with HER2-positive metastatic breast cancer (mBC). 

 

The findings, based on an exploratory analysis, indicate that CD47 expression may predict which patients benefit most from the therapy.

 

"These new findings support a CD47-dependent, HER2-driven biology for evorpacept," said Barbara Klencke, Chief Medical Officer at ALX Oncology. 

 

"Going forward, we believe that a biomarker-driven approach incorporating CD47 expression may optimize patient selection for evorpacept combinations with HER2-targeted agents. Additionally, taken together, the data from this trial and the ASPEN-06 clinical trial reinforce our confidence in the ongoing ASPEN-09-Breast Phase 2 trial."

 

The open-label, multi-center trial evaluated evorpacept in combination with Jazz Pharmaceuticals’ ZIIHERA (zanidatamab-hrii) in patients with previously treated, inoperable, or metastatic HER2-expressing breast cancer. 

 

Initial results showed the combination generated promising anti-tumor activity and a manageable safety profile in patients who had received a median of six prior therapies, including ENHERTU. Nine patients with centrally confirmed HER2-positive tumors achieved a 56% confirmed objective response rate (cORR) and a median progression-free survival (mPFS) of 7.4 months.

 

The new biomarker-focused analysis revealed that responses were largely restricted to patients with higher CD47 expression, echoing findings from ALX Oncology’s ASPEN-06 trial in HER2-positive advanced gastric cancer.

 

The company plans to present the full biomarker analysis from the Phase 1b/2 trial at an upcoming scientific congress.