Pertuzumab

證據等級: L5

預測適應症: 10 個

Pertuzumab: From HER2-Positive Breast Cancer to Normal Breast-Like Subtype of Breast Carcinoma

One-Sentence Summary

Pertuzumab (DrugBank DB06366) is a HER2-targeted monoclonal antibody with an established role in HER2-positive breast cancer treatment (in combination with trastuzumab and chemotherapy); this general indication is well known but is not present in this Evidence Pack’s structured registry data, since Pertuzumab is currently not marketed in Denmark. The TxGNN model predicts a possible extension to the normal breast-like molecular subtype of breast carcinoma, but this specific hypothesis is currently supported only by 6 clinical trials (none of them subtype-specific) and no dedicated literature. Within the same prediction set, closely related hypotheses — PR-positive and PR-negative breast cancer — carry substantially stronger evidence (L1, multiple completed Phase 3 RCTs) and should be considered alongside this candidate (see Conclusion).

Quick Overview

Item	Content
Original Indication	HER2-positive breast cancer (established drug-class use; not present in Danish registry data — see Data Gap)
Predicted New Indication	Normal breast-like subtype of breast carcinoma
TxGNN Prediction Score	99.93%
Evidence Level	L2
Denmark Market Status	Not Marketed
Number of Marketing Authorisations	0
Recommended Decision	Research Question

Why is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available in this Evidence Pack (Data Gap DG002, severity: High). Based on known pharmacological information, Pertuzumab is a recombinant humanized monoclonal antibody that binds the extracellular dimerization domain (subdomain II) of HER2, blocking HER2-HER3 heterodimerization and downstream PI3K/AKT signalling. It is used in combination with trastuzumab (and typically a taxane) for HER2-positive breast cancer, where its efficacy is well established.

“Normal breast-like” is one of the PAM50 intrinsic molecular subtypes of breast cancer, defined primarily by gene-expression profiling rather than by HER2 receptor status. None of the clinical trials retrieved for this candidate specifically enrolled patients by PAM50 subtype — they were designed around conventional HER2-positive breast cancer populations (e.g., biology-driven neoadjuvant selection studies), and the association with “normal breast-like” subtype is inferred only indirectly, through the overlap between “HER2-positive” and this molecular subtype. No dedicated literature was retrieved to support this specific link.

By contrast, within the same TxGNN prediction set for this drug, progesterone-receptor (PR) positive and PR-negative breast cancer carry much stronger, more direct supporting evidence, including completed Phase 3 randomized trials and a real-world cohort study (PMID 37723497) showing PR status modifies the magnitude of pertuzumab’s neoadjuvant benefit. This suggests the receptor-status subtypes are mechanistically better substantiated hypotheses than the PAM50 “normal breast-like” subtype evaluated here (see Conclusion for details).

Important caveat: All rationale above assumes the tumor is HER2-positive. Confirmation of HER2-positive status is a prerequisite for any of these repurposing hypotheses, and this field is not available in the current Evidence Pack.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT05900206	Phase 2	Recruiting	370	ARIADNE: compares trastuzumab deruxtecan to standard preoperative treatment in non-metastatic HER2-positive breast cancer, using biology-driven treatment selection; no results yet.
NCT04329065	Phase 2	Recruiting	25	WOKVAC vaccine combined with neoadjuvant chemotherapy and HER2-targeted monoclonal antibody therapy; small exploratory immunotherapy study.
NCT01796197	Phase 2	Completed	23	Paclitaxel + trastuzumab + pertuzumab as preoperative therapy for inflammatory breast cancer; regimen-relevant but not subtype-specific.
NCT05582499	Phase 2	Recruiting	716	FASCINATE-N: precision neoadjuvant therapy platform based on clinical/molecular subtyping of operable breast cancer.
NCT06348134	Phase 2	Recruiting	74	Efficacy/safety of optimal neoadjuvant-to-adjuvant anti-HER2 therapy in Nigerian women with HER2-positive breast cancer.
NCT04750122	Phase 1/2	Recruiting	46	Neoadjuvant therapy guided by drug-screening in patient-derived tumor-cell clusters for HER2-positive early breast cancer.

Literature Evidence

Currently no related literature available for this specific predicted indication (normal breast-like subtype of breast carcinoma).

Denmark Market Information

Pertuzumab currently has no marketing authorisations on file in Denmark (market status: Not Marketed; total licenses: 0). No product-level dosage form or approved-indication data is available from the Danish registry for this Evidence Pack.

Cytotoxicity

Item	Content
Cytotoxicity Classification	Targeted therapy (anti-HER2 monoclonal antibody; not a conventional cytotoxic agent)
Myelosuppression Risk	Please refer to the Summary of Product Characteristics (SmPC) warnings and precautions
Emetogenicity Classification	Please refer to the Summary of Product Characteristics (SmPC) warnings and precautions
Monitoring Items	Please refer to the Summary of Product Characteristics (SmPC) warnings and precautions
Handling Protection	Please refer to the Summary of Product Characteristics (SmPC) warnings and precautions

Safety Considerations

Please refer to the approved Summary of Product Characteristics (SmPC) for safety information. No key warnings, contraindications, or drug-drug interaction data are currently available in this Evidence Pack (DDI query status: not found).

Note: A Blocking-severity data gap has been identified — the Danish/EU product label (warnings and contraindications) has not yet been obtained (DG001), which prevents this candidate from entering the S1 safety pre-screening stage. This should be resolved before any further evaluation proceeds.

Conclusion and Next Steps

Decision: Research Question

Rationale: The “normal breast-like subtype” hypothesis is supported only by L2-level evidence — a single completed Phase 2 trial in a related but non-subtype-specific population, no dedicated literature, and no confirmed HER2-positive status for the target population. Combined with a Blocking-severity gap in safety labelling data, this candidate is not yet ready to advance beyond a research question.

Notably, within this same prediction batch, PR-positive and PR-negative breast cancer subtypes are supported by L1 evidence (≥2 completed Phase 3 RCTs, including IMpassion050 [NCT03726879] and the QL1209 biosimilar equivalence trial [NCT04629846]) and are already rated “Proceed with Guardrails.” These related hypotheses represent a more evidence-mature repurposing opportunity for the same drug and disease area, and may warrant prioritized follow-up evaluation ahead of, or alongside, the normal breast-like subtype candidate.

To proceed, the following is needed:

Danish/EU product label (SmPC) — warnings, contraindications, and DDI data (Blocking gap, DG001)
Detailed mechanism of action confirmation from DrugBank (High-priority gap, DG002)
Confirmation of HER2-positive status as an inclusion criterion for the target population
Subtype-specific (PAM50 “normal breast-like”) clinical trial or literature evidence, since current evidence is only indirectly applicable
A parallel evaluation of the PR-positive/PR-negative breast cancer candidates from this same prediction set, given their stronger (L1) evidence base
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.