Table 1.
Eligibility criteria of TRIUMPH study.
| IHC | IHC Pattern | Classification | Eligibility |
|---|---|---|---|
| Surgical specimen | Complete lateral or circumferential membrane staining with strong intensity and within >10% of tumor cells | Positive IHC (3+) |
Eligible (tissue +) |
| Biopsy specimen | Tumor cells with complete lateral of circumferential membrane staining with strong intensity irrespective of percentage of tumor cells stained | ||
| Surgical specimen | Incomplete lateral or circumferential membrane staining with weak/moderate intensity and within >10% of tumor cells or complete lateral or circumferential membrane staining with strong intensity and within <10% of tumor cells | Equivocal IHC (2+) |
Not eligible |
| Biopsy specimen | Tumor cells with weak to moderate complete circumferential or weak to moderate lateral membrane staining irrespective of percentage of tumor cells stained | ||
| Surgical specimen | Segmental of granular staining in any cellularity | Negative IHC (1+) |
Not eligible |
| Biopsy specimen | Tumor cells with faint or barely perceptible membrane staining irrespective of percentage of tumor cells stained | ||
| Surgical specimen | No staining is observed or incomplete membrane staining with faint/barely perceptible intensity and within ≤10% of tumor cells | Negative IHC (0+) |
Not eligible |
| Biopsy specimen | No staining in any tumor cell | ||
| FISH | HER2/CEP17 ratio | ||
| Surgical or biopsy specimen | ≥2 | Positive | Eligible (tissue +) |
| <2 | Negative | Not eligible | |
| Plasma NGS | HER2 status by Gurdant360 | ||
| ctDNA | HER2 amplification (and KRAS/NRAS wild type) | Positive | Eligible (blood +) |
| No HER2 amplification | Negative | Not eligible |
Eligible (tissue +): if a patient meets either of the following criteria based on analysis of tumor tissue in central pathological assessment* using the HER2 IHC test and HER2 FISH test, IHC3+ or FISH-positive (HER2/CEP17 ratio ≥ 2.0). Eligible (blood +): if a patient has HER2 amplification (HER2-positive) and wild-type RAS† based on the analysis of a blood sample in central assessment* using liquid biopsy. † Wild-type RAS is defined as “Relative clonality††, i.e., ≤ 30% in each of KRAS codon 12, 13, 59, 61, 117, and 146, and NRAS of codon 12, 13, 59, 61, 117, and 146”. †† Relative clonality (%) = % cfDNA of a certain mutation/highest % cfDNA × 100. * The HER2 test of tumor tissue, liquid biopsy using blood samples, and central assessment of the results are performed separately in clinical research. Abbreviations: IHC, immunohistochemistry; FISH, fluorescence in situ hybridization; NGS, next-generation sequencing; cfDNA, cell-free DNA; ctDNA, circulating tumor DNA.