New Data Demonstrate CD47 Expression Level Helps Predict Response to ALX Oncology’s Evorpacept in Combination with Ziihera (zanidatamab-hrii) in Advanced HER2-Positive Breast Cancer

Rhea-AI Summary

ALX Oncology (Nasdaq: ALXO) reported exploratory Phase 1b/2 data showing CD47 expression predicts response to investigational CD47 inhibitor evorpacept combined with Ziihera (zanidatamab-hrii) in HER2-positive metastatic breast cancer. In nine centrally confirmed HER2-positive patients the combination produced a 56% confirmed objective response rate and median PFS of 7.4 months. The full biomarker analysis has been submitted for presentation at an upcoming scientific congress and reinforces prior ASPEN-06 gastric cancer findings linking CD47 expression to benefit.

Positive

• Confirmed objective response rate 56% (5/9) in HER2-positive cohort
• Median progression-free survival of 7.4 months in HER2-positive patients
• Biomarker finding reinforced by prior ASPEN-06 gastric cancer results

Negative

• Small evaluable HER2-positive sample: 9 patients, limiting statistical confidence
• Patients were heavily pretreated with a median of 6 prior therapies

Key Figures

Confirmed ORR: 56% (5/9) Median PFS: 7.4 months Median prior therapies: 6 prior therapies +5 more

8 metrics

Confirmed ORR 56% (5/9) Phase 1b/2 HER2-positive metastatic breast cancer cohort on evorpacept + zanidatamab

Median PFS 7.4 months Nine patients with centrally confirmed HER2-positive breast cancer on combination

Median prior therapies 6 prior therapies Heavily pretreated HER2-positive metastatic breast cancer population

Trial identifier NCT05027139 Phase 1b/2 open-label, multi-center trial of evorpacept + zanidatamab

Patient count 9 patients Centrally confirmed HER2-positive breast cancer subgroup analyzed

Price move 14.6% ALXO 24h price change before/around biomarker data release

52-week range $0.404–$2.27 Current price <b>1.57</b> sits between 52-week low and high

Option award 912,000 options at $1.48 CEO stock option grant expiring January 25, 2036

Market Reality Check

Price: $1.74 Vol: Volume 550,353 is 2.2x th...

high vol

$1.74 Last Close

Volume Volume 550,353 is 2.2x the 20-day average of 250,107, indicating elevated interest into this data update. high

Technical Shares at 1.57 are trading above the 200-day MA of 1.02, while still 30.84% below the 52-week high of 2.27.

Peers on Argus

ALXO gained 14.6% while close peers showed mixed moves: APLT +4.95%, CUE +0.5%, ...

ALXO gained 14.6% while close peers showed mixed moves: APLT +4.95%, CUE +0.5%, but ARTV -6.32%, INKT -3.89%, HOWL -2.08%, pointing to a company-specific reaction.

Historical Context

5 past events · Latest: 2026-01-08 (Neutral)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
2026-01-08	Investor conference	Neutral	+5.1%	J.P. Morgan Healthcare Conference corporate presentation and fireside chat announcement.
2026-01-08	Pipeline update	Positive	+5.1%	ASPEN-09-Breast Phase 2 and ALX2004 trial advancement with biomarker-focused design.
2025-12-07	Clinical trial data	Positive	+1.4%	Positive Phase 2 lymphoma results with 100% overall response rate for evorpacept combo.
2025-11-18	Investor conferences	Neutral	+4.5%	Upcoming Jefferies and Piper Sandler healthcare conference presentations and webcasts.
2025-11-07	Earnings and pipeline	Positive	+16.9%	Q3 2025 results plus strong ASPEN-06 CD47-high gastric cancer data and cash runway update.

Pattern Detected

Recent ALXO news, especially clinical and corporate updates, has typically been followed by positive price reactions, including a 16.95% move on Q3 2025 results and multiple ~5% gains on conference and pipeline announcements.

Recent Company History

Over the past several months, ALXO has highlighted steady clinical and corporate progress. Q3 2025 results showcased strong evorpacept data in HER2-positive, CD47-high gastric cancer and confirmed cash of $66.5 million funding operations into Q1 2027. Subsequent updates covered ASPEN-09-Breast trial initiation plans, positive Phase 2 lymphoma data, and repeated investor conference appearances. The current breast cancer biomarker analysis extends the CD47-driven narrative established in prior gastric cancer data.

Market Pulse Summary

This announcement highlights exploratory Phase 1b/2 data suggesting CD47 expression helps predict re...

Analysis

This announcement highlights exploratory Phase 1b/2 data suggesting CD47 expression helps predict response to evorpacept plus zanidatamab in HER2-positive metastatic breast cancer, echoing prior ASPEN‑06 gastric cancer findings. It reinforces a biomarker-driven development strategy, consistent with earlier updates on ASPEN‑09 and other evorpacept programs. Investors may watch for the full dataset at the upcoming conference and subsequent trial readouts to assess durability, safety, and how these insights could influence future study designs.

Key Terms

cd47, biomarker, her2-positive, metastatic breast cancer, +3 more

7 terms

cd47 medical

"Exploratory analysis from Phase 1b/2 breast cancer trial reinforces CD47 as a predictive biomarker"

A cell surface protein that acts like a “don’t eat me” signal to the immune system, helping healthy and some diseased cells avoid destruction by immune cells. Investors should care because therapies that block or modulate this protein are a major approach in cancer and immune disease drug development; clinical trial results, safety, and regulatory decisions around CD47-targeting treatments can strongly affect the value of companies developing them.

biomarker medical

"reinforces CD47 as a predictive biomarker for response, as previously observed in the ASPEN-06 trial"

A biomarker is a measurable indicator found in the body, such as in blood or tissues, that provides information about health, disease, or how the body responds to treatment. For investors, biomarkers can signal the potential success or risk of medical products or therapies, influencing the value of related companies and industry trends. They act like signals or clues that help assess the progress of medical advancements and their market impact.

her2-positive medical

"advanced HER2-positive breast cancer"

HER2-positive describes cancer cells that have too many copies of the HER2 gene or make too much of the HER2 protein, which acts like an overactive growth switch that drives tumor growth. For investors, HER2 status matters because it determines whether patients can receive specific, often expensive targeted therapies and diagnostic tests, so trial results, approvals, or competing drugs tied to HER2 can strongly affect drug sales and company value.

metastatic breast cancer medical

"in heavily pretreated patients with metastatic breast cancer (mBC)"

Metastatic breast cancer is breast cancer that has spread beyond the breast and nearby lymph nodes to other organs, such as bones, liver, lungs or brain. For investors it matters because these advanced-stage cases often require long-term, complex and costly treatments, drive demand for specialty drugs and diagnostics, and influence regulatory approvals, pricing negotiations and the long-term revenue potential of companies developing therapies aimed at slowing spread or improving quality of life. An everyday analogy: it’s like a weed that has taken root in multiple beds rather than just one garden patch, requiring broader and more sustained effort to manage.

phase 1b/2 medical

"The Phase 1b/2 open-label, multi-center clinical trial (NCT05027139) evaluated the potential"

Phase 1b/2 is a combined early-stage human study that first checks a drug’s safety and side effects in a small group and then expands to test whether it shows signs of working in patients. Think of it as a product test that first confirms it’s safe to use, then looks for early evidence of benefit; positive results can significantly reduce clinical risk and increase a company’s value, while negative results raise the opposite.

objective response rate medical

"reported a 56% (5/9) confirmed objective response rate (cORR) and a median"

The objective response rate (ORR) is the percentage of patients in a clinical trial whose tumors measurably shrink or disappear according to preset rules. Investors use it as a quick, objective signal of a drug’s ability to produce a clear treatment effect—like counting how many plants visibly respond after applying a new fertilizer—and higher ORR can improve odds of regulatory approval, commercial success, and company valuation.

median progression-free survival medical

"objective response rate (cORR) and a median progression-free survival (mPFS) of 7.4 months"

Median progression-free survival is the length of time at which half of patients in a clinical study have not experienced disease worsening or progression. Think of it like the moment in a race when 50% of runners have not yet crossed a trouble line—it shows how long a therapy can delay disease activity for a typical patient. Investors use it as a straightforward signal of a drug’s effectiveness that can influence regulatory approval, market demand, and revenue potential.

AI-generated analysis. Not financial advice.

- Exploratory analysis from Phase 1b/2 breast cancer trial reinforces CD47 as a predictive biomarker for response, as previously observed in the ASPEN-06 trial in HER2-positive gastric cancer –

- Full data set submitted for presentation at an upcoming scientific conference -

SOUTH SAN FRANCISCO, Calif., Jan. 30, 2026 (GLOBE NEWSWIRE) -- ALX Oncology Holdings Inc. (“ALX Oncology,” Nasdaq: ALXO), a clinical-stage biotechnology company advancing a pipeline of novel therapies designed to treat cancer and extend patients’ lives, announced new data from a Phase 1b/2 clinical trial evaluating the company’s investigational CD47-inhibitor evorpacept in combination with Jazz Pharmaceuticals’ ZIIHERA® (zanidatamab-hrii) in heavily pretreated patients with metastatic breast cancer (mBC). The topline findings, from an exploratory analysis in this trial, indicate that among patients with confirmed HER2-positive mBC, CD47 expression is predictive of evorpacept activity.

“These new findings support a CD47-dependent, HER2-driven biology for evorpacept,” said Barbara Klencke, M.D., 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 Phase 1b/2 open-label, multi-center clinical trial (NCT05027139) evaluated the potential of evorpacept in combination with zanidatamab as a novel treatment for patients with previously treated, inoperable, locally advanced, or metastatic HER2-expressing breast cancer and other cancers. The primary trial results, presented at the 2024 San Antonio Breast Cancer Symposium (SABCS), demonstrated that the investigational combination generated promising anti-tumor activity and a manageable safety profile in patients with heavily pretreated HER2-positive breast cancer (median of six prior therapies), including treatment with ENHERTU. Researchers previously reported a 56% (5/9) confirmed objective response rate (cORR) and a median progression-free survival (mPFS) of 7.4 months in the nine patients with centrally confirmed HER2-positive breast cancer who received the investigational combination.

The additional exploratory analysis, conducted to identify biomarkers of response to the evorpacept/zanidatamab combination, shows that responses in this trial were largely restricted to patients with higher CD47 expression. This finding reinforces results from the ASPEN-06 clinical trial, which demonstrated that CD47 expression is a predictive biomarker for response and durable benefit from evorpacept among patients with advanced gastric cancer that has retained HER2 expression.

The full biomarker analysis from the Phase 1b/2 clinical trial has been submitted to an upcoming scientific congress for presentation.

About ALX Oncology
ALX Oncology (Nasdaq: ALXO) is a clinical-stage biotechnology company advancing a pipeline of novel therapies designed to treat cancer and extend patients’ lives. ALX Oncology’s lead therapeutic candidate, evorpacept, has demonstrated potential to serve as a cornerstone therapy upon which the future of immuno-oncology can be built. Evorpacept is currently being evaluated across multiple ongoing clinical trials in a wide range of cancer indications. ALX Oncology’s second pipeline candidate, ALX2004, is a novel EGFR-targeted antibody-drug conjugate with a differentiated mechanism of action. A Phase 1, dose-escalation trial of ALX2004 is ongoing in patients with EGFR-expressing solid tumors. More information is available at www.alxoncology.com and on LinkedIn @ALX Oncology.

Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements that involve substantial risks and uncertainties. Forward-looking statements include statements regarding future results of operations and financial position, business strategy, product candidates, planned preclinical studies and clinical trials, results of clinical trials, research and development costs, regulatory approvals, timing and likelihood of success, plans and objects of management for future operations, as well as statements regarding industry trends. Such forward-looking statements are based on ALX Oncology’s beliefs and assumptions and on information currently available to it on the date of this press release. Forward-looking statements may involve known and unknown risks, uncertainties and other factors that may cause ALX Oncology’s actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. These and other risks are described more fully in ALX Oncology’s filings with the Securities and Exchange Commission (SEC), including ALX Oncology’s Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and other documents ALX Oncology files with the SEC from time to time. Except to the extent required by law, ALX Oncology undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

Investor Relations Contact:
Elhan Webb, CFA, IR Consultant
ewebb@alxoncology.com

Media Contact:
Michele Parisi, SparkPoint Healthcare Communications
mparisi@sparkpointpr.com
(925) 864-5028

FAQ

What did ALX Oncology report about CD47 and evorpacept in HER2-positive breast cancer (ALXO)?

ALX Oncology reported that higher CD47 expression predicts response to evorpacept plus Ziihera in HER2-positive mBC. According to ALX Oncology, an exploratory analysis showed responses were largely restricted to patients with higher CD47 expression, supporting biomarker-driven selection.

What were the key efficacy metrics for evorpacept plus Ziihera in the Phase 1b/2 HER2-positive cohort (ALXO)?

The investigational combination produced a 56% confirmed objective response rate and median PFS 7.4 months in nine centrally confirmed HER2-positive patients. According to ALX Oncology, these topline results were observed in heavily pretreated patients.

How does the new biomarker data affect the ASPEN-09-Breast Phase 2 trial for ALXO?

The CD47 biomarker results support a biomarker-driven patient selection approach for ASPEN-09-Breast. According to ALX Oncology, the findings reinforce confidence in ongoing Phase 2 strategy and potential enrichment of responsive patients.

Has ALX Oncology submitted the full biomarker analysis for presentation (ALXO)?

Yes, ALX Oncology has submitted the complete biomarker analysis to an upcoming scientific congress for presentation. According to ALX Oncology, the full dataset will provide detailed evidence linking CD47 expression to response in the trial.

Who were the patients in the Phase 1b/2 trial of evorpacept plus Ziihera (ALXO)?

The trial enrolled heavily pretreated patients with inoperable or metastatic HER2-expressing cancers, median six prior therapies. According to ALX Oncology, the HER2-positive subgroup included nine centrally confirmed patients evaluated for response.

How do these breast cancer biomarker results relate to prior ALXO findings in gastric cancer?

The breast cancer analysis mirrors ASPEN-06 gastric cancer results showing CD47 expression predicts durable benefit with evorpacept. According to ALX Oncology, this cross-indication consistency strengthens the biomarker hypothesis for evorpacept combinations.