ACE-Breast-02
A site-specifically conjugated HER2 ADC beat lapatinib-capecitabine on progression-free survival in China.
PFS 11.3 vs 8.2 months (HR 0.64). ARX788 uses non-natural amino acid conjugation (Ambrx, now J&J) with an MMAF-like payload (AS269); ocular and pulmonary toxicity noted. Marketing application planned in China; FDA Fast Track.
Setting
HER2+ advanced breast cancer after trastuzumab and taxane (China): ARX788 vs lapatinib + capecitabine
Phase
Phase 3
Sponsor
Zhejiang Medicine / Ambrx
Registry
Headline result
PFS 11.3 vs 8.2 months, HR 0.64.
Reported
2024
Enrolled
441
Replication
Single phase 3; ACE-Breast-06 (brain metastases, phase 2) supportive.
In plain words
What these results mean for people, not percentages
Progression-free survivalprimarysurrogate endpoint
- Median 11.3 vs 8.2 months with ARX788 compared with Lapatinib + capecitabine; about 3.1 months longer for half the group.
- A median is a midpoint: half the people did better than this and half did worse, so it is not a prediction for any one person.
- Put another way, the treated group had about 36 percent lower chance of the event at any given time (hazard ratio 0.64).
- This is a surrogate endpoint: it measures the cancer being controlled or absent on scans and tests, which often, but not always, translates into living longer.
- These results apply to the people the trial enrolled: HER2+ advanced breast cancer after trastuzumab and taxane (China): ARX788 vs lapatinib + capecitabine. People in a different situation may not see the same effect.
- The trial selected people by a biomarker (HER2); the result should not be assumed for people whose cancer does not have it.
Numbers are from the trial as recorded here; see the source links in the table below. This is orientation, not medical advice: ask your team how closely the trial population matches you.
441 participants enrolled.
| Endpoint | Arm | n | Value | HR (95% CI) | p | Source |
|---|---|---|---|---|---|---|
| Progression-free survivalprimary | ARX788 | — | 11.3 months | 0.64 | — | link |
| Lapatinib + capecitabine | — | 8.2 months |
Replication
Single phase 3; ACE-Breast-06 (brain metastases, phase 2) supportive.