Neratinib
| Evidence Level: L2 | Predicted Indications: 10 |
Table of Contents
- Neratinib
- Neratinib: From HER2-Positive Breast Cancer to Progesterone-Receptor Positive Breast Cancer
Neratinib: From HER2-Positive Breast Cancer to Progesterone-Receptor Positive Breast Cancer
One-Sentence Summary
Neratinib is an irreversible pan-HER tyrosine kinase inhibitor, originally used to treat HER2-positive breast cancer. The TxGNN model predicts it may be effective for progesterone-receptor positive breast cancer, with 2 clinical trials (1 recruiting Phase 2, 1 withdrawn) and 12 publications currently supporting this direction. Much of this prediction overlaps with the already approved HER2-positive population, so it is largely an extension of the existing indication rather than a true repurposing.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | HER2-positive breast carcinoma |
| Predicted New Indication | Progesterone-receptor positive breast cancer |
| TxGNN Prediction Score | 99.68% |
| Evidence Level | L2 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Proceed with Guardrails |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available in the data compiled for this report. Based on known information, neratinib is an irreversible tyrosine kinase inhibitor of HER1, HER2 and HER4. Its efficacy in HER2-positive breast cancer has been demonstrated, including as extended adjuvant therapy in the hormone receptor-positive subset.
Progesterone-receptor positive tumours overlap heavily with the HR-positive/HER2-positive population already covered by the approved use. The ExteNET Phase 3 trial tested 12 months of neratinib after trastuzumab-based adjuvant therapy in early-stage HER2-positive breast cancer. Real-world studies of adjuvant neratinib in HR+/HER2+ disease (2024 and 2026) also support this use. Two Phase 2 trials test neratinib with endocrine therapy, which reflects the biological cross-talk between HER2 and hormone receptor signalling.
Two cautions apply. The ExteNET publication is available only as a title and short abstract in the data compiled, so the evidence level has been set conservatively at L2 rather than L1. Neratinib is also well known for diarrhoea, which requires prophylaxis.
Clinical Trial Evidence
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT04886531 | Phase 2 | Recruiting | 30 | Pre-operative neratinib + aromatase inhibitor + trastuzumab for 24 weeks in ER-positive/HER2-positive early breast cancer; no results yet |
| NCT04901299 | Phase 2 | Withdrawn | 0 | Neratinib + fulvestrant in previously treated HR-positive/HER2-negative metastatic breast cancer; no participants enrolled, so no evidence |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 26874901 | 2016 | RCT | Lancet Oncology | ExteNET: 12 months of neratinib after trastuzumab-based adjuvant therapy in early-stage HER2-positive breast cancer |
| 35640077 | 2022 | Guideline | J Clin Oncol | ASCO guideline update on systemic therapy for advanced HER2-positive breast cancer |
| 29784737 | 2018 | Guideline | J Natl Compr Canc Netw | NCCN breast cancer updates, including CDK4/6 inhibitors in ER-positive disease |
| 27406346 | 2016 | Adaptive Phase 2 trial | N Engl J Med | I-SPY 2: neratinib added to standard neoadjuvant chemotherapy in high-risk early breast cancer |
| 39153126 | 2024 | Cohort | Breast Cancer Res Treat | Use and tolerance of adjuvant neratinib in HR+/HER2+ early breast cancer; GI side effects often lead to discontinuation |
| 41499317 | 2026 | Cohort | Oncology | Current prescribing trends of adjuvant neratinib in HR+/HER2+ breast cancer |
| 33726508 | 2021 | Review | Future Oncol | Current trends in treating HR+/HER2+ breast cancer, including neratinib |
| 32139271 | 2020 | Review | Clin Breast Cancer | Expert roundtable on practice guidance for HER2-positive breast cancer |
| 41886605 | 2026 | Preclinical | Cancer Research | BRD8/EP400 chromatin module mediates anti-HER2 response in HR+/HER2+ breast cancer |
| 35251981 | 2022 | Case report | Front Oncol | Pyrotinib plus vinorelbine in HER2-positive breast cancer with leptomeningeal disease (not neratinib) |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN15861P | NERLYNX FILM-COATED TABLETS 40 MG | Film-coated tablet | Not stated in the data compiled |
Cytotoxicity
| Item | Content |
|---|---|
| Cytotoxicity Classification | Targeted therapy (irreversible pan-HER tyrosine kinase inhibitor) |
| Myelosuppression Risk | Please refer to the package insert warnings and precautions |
| Emetogenicity Classification | Please refer to the package insert warnings and precautions |
| Monitoring Items | Liver function and diarrhoea/hydration status; please also refer to the package insert |
| Handling Protection | Please refer to the package insert warnings and precautions |
Safety Considerations
- Known toxicity: Diarrhoea is a well-recognised toxicity and requires prophylaxis. Gastrointestinal side effects often lead to treatment discontinuation (PMID 39153126).
- Drug Interactions: 100 interactions were identified in the data compiled; the first 20 are reviewed here. Most are Major, including:
- Acid-suppressing agents: famotidine, ranitidine, cimetidine, and the proton pump inhibitors rabeprazole, omeprazole, esomeprazole, lansoprazole and dexlansoprazole
- Aprepitant, dexamethasone, clarithromycin and clotrimazole
- Moderate interactions include loperamide, antacids (magnesium oxide, aluminium hydroxide, calcium carbonate), empagliflozin and naldemedine. Naloxegol and fidaxomicin are Minor.
- Loperamide is the usual antidiarrhoeal prophylaxis, so its interaction deserves attention when planning prophylaxis.
For full warnings and contraindications, please refer to the package insert.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: Neratinib is already approved for HER2-positive breast cancer, and the PR-positive population largely falls within the HR+/HER2+ group studied in ExteNET. Direct evidence is limited to one small recruiting Phase 2 trial with no results, so the strength of evidence is moderate (L2).
To proceed, the following is needed:
- Package insert warnings, contraindications and the approved indication text for SIN15861P (not available in the data compiled)
- Detailed mechanism of action data
- Full ExteNET results (including HR-positive subgroup) and results from NCT04886531
- A diarrhoea prophylaxis plan that accounts for the acid-suppressant and loperamide interactions
- Clarification that the use is limited to HER2-positive (or HER2-mutant) disease, as there is no evidence for HER2-negative PR-positive tumours
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.