Ribociclib
| Evidence Level: L4 | Predicted Indications: 4 |
Table of Contents
Ribociclib: From Breast Cancer to Myeloid Leukemia
One-Sentence Summary
Ribociclib (Kisqali) is a CDK4/6 inhibitor marketed in Canada and, based on the literature compiled for this report, used in hormone receptor-positive, HER2-negative breast cancer. The TxGNN model predicts it may be effective for myeloid leukemia, but this rests on 0 clinical trials and 1 relevant preclinical publication. This is a research question, not a clinical recommendation.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Hormone receptor-positive, HER2-negative breast cancer (inferred from the literature; the Canadian licence text compiled for this report is blank) |
| Predicted New Indication | Myeloid leukemia |
| TxGNN Prediction Score | 0.9935 |
| Evidence Level | L4 |
| Canada Market Status | Marketed (marketed DINs: 1 of 1) |
| Number of DINs | 1 (marketed: 1) |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Detailed mechanism of action data is not available in the data compiled for this report. Based on known information, ribociclib is a selective CDK4/6 inhibitor. CDK4/6 drives cells through the G1-to-S phase of the cell cycle, and blocking it halts proliferation of cells that depend on this pathway.
This gives a plausible link to myeloid leukemia, where rapidly dividing blasts may rely on the same cell-cycle machinery. A 2020 preclinical study (PMID 32560251) reported that CDK4/6 inhibitors can target pharmacokinetic drug resistance in acute myeloid leukemia cells. This resistance is linked to ABCB1 and ABCG2 transporters and to drug-metabolising enzymes.
The evidence is in vitro only. No clinical efficacy data for ribociclib in myeloid leukemia were identified. The prediction is therefore a hypothesis worth testing in the laboratory, not a proven benefit.
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 32560251 | 2020 | Preclinical (in vitro) | Cancers | CDK4/6 inhibitors may target pharmacokinetic drug resistance (ABCB1/ABCG2 transporters, carbonyl reducing enzymes) in AML cells |
A second publication retrieved for this prediction (PMID 41641105) is a case report of vulvar adenocarcinoma and is not relevant to myeloid leukemia, so it is not listed.
Canada Market Information
| DIN | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| 02473569 | KISQALI | Not specified | Not specified |
Cytotoxicity
| Item | Content |
|---|---|
| Cytotoxicity Classification | Targeted therapy (CDK4/6 inhibitor) |
| Myelosuppression Risk | High. Neutropenia, leukopenia, thrombocytopenia and anaemia are widely reported with CDK4/6 inhibitors |
| Emetogenicity Classification | Please refer to the package insert warnings and precautions |
| Monitoring Items | Complete blood count with differential, liver function, ECG/QT interval and electrolytes (standard practice for this class) |
| Handling Protection | Please refer to the package insert warnings and precautions |
Safety Considerations
- Haematological toxicity: The literature identifies myelosuppression as the most common toxicity of CDK4/6 inhibitors. This includes an umbrella review of meta-analyses (PMID 38288438), pharmacovigilance analyses (PMIDs 39123221, 37895811) and a network meta-analysis (PMID 38753541). This is particularly important in a disease like leukemia, where marrow function is already compromised.
- Other reported adverse events: Pneumonitis (case report, PMID 34248473) and visual hallucination (case report, PMID 37306182).
- Drug Interactions: 100 interactions were found in the DDI screening, of which 20 are listed in the data compiled for this report. Most are Moderate, and two are Major:
- Clarithromycin (Major)
- Dolasetron (Major)
- Moderate examples: famotidine, hydrocortisone, metformin, pioglitazone, loperamide, aprepitant, dexamethasone, cimetidine
Health Canada package insert warnings and contraindications were not available. They must be obtained before any safety screening.
Conclusion and Next Steps
Decision: Hold
Rationale: The high TxGNN score is supported only by a single in vitro study, with no clinical trials. Ribociclib’s marked myelosuppression is a significant safety concern in leukemia. The other top-ranked predictions (thrombocytopenia and related inherited platelet disorders) are likely a reversed signal. Ribociclib causes thrombocytopenia rather than treating it, and no supporting trials or literature exist for them.
To proceed, the following is needed:
- Health Canada package insert warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data from DrugBank
- Confirmation of the approved indication text for DIN 02473569
- Further preclinical work in AML models (cell lines, patient-derived samples), including combinations with standard induction therapy
- A review of myelosuppression risk specific to leukemia patients before any clinical study is considered
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.