Valspodar
Also known as: Cyclosporin D analogue MDR inhibitor, PSC 833, PSC-833, PSC833, SDZ PSC 833, Valspodar
Source Valspodar at Peptiology
Save 10% with code PEPTI-BOSSRABBIT-10
Tapping Shop Now & Save 10% copies your 10% off code PEPTI-BOSSRABBIT-10 to your clipboard. Paste it at the Peptiology checkout to claim the discount.
Summary
Valspodar (PSC833) is a cyclosporine A analog developed as a selective P‑glycoprotein inhibitor to reverse multidrug resistance in cancer chemotherapy. It has been evaluated in Phase I‑II trials but never received regulatory approval.
Mechanism of Action
Potent inhibition of the P-glycoprotein (ABCB1) efflux transporter, leading to increased intracellular concentrations of co‑administered chemotherapeutic agents; retains cyclophilin binding but lacks calcineurin‑mediated immunosuppression.
Routes of Administration
Goals & Uses
- Reversal of multidrug resistance in cancerOncology / Pharmacology ResearchModerate
- Improved chemotherapy efficacy in solid tumorsOncology / Solid TumorsLow
- Improved chemotherapy efficacy in AMLOncology / Hematologic MalignancyLow
- Multidrug resistance reversalOncologyModerate
Contraindications
- Severe hepatic impairmentOrganHighLiver function concerns
- Concurrent use with drugs highly dependent on CYP3A4/P-gp for clearanceDrug InteractionHigh
- Hypersensitivity to cyclosporine or its analoguesAllergyHigh
Adverse Effects
- Hypersensitivity reactionsImmunologicRare
- NeurotoxicityNeurologicalUncommon
- Hepatotoxicity (elevated transaminases)HepaticUncommon
- Enhanced chemotherapy toxicity (myelosuppression, neuropathy)Pharmacokinetic Interaction Mediated ToxicityCommon
- Nausea/vomitingGastrointestinalCommon
- Nausea and vomitingGastrointestinalCommon
- Neurotoxicity (tremor, paresthesia)NeurologicalRare
- Hyperbilirubinemia / hepatotoxicityHepaticUncommon
Drug Interactions
- DoxorubicinHigh
- DigoxinLow
- PaclitaxelModerate
- Cyclosporin AModerate
- EtoposideModerate
- VincristineHigh
Population Constraints
- PregnancyReproductive SafetyAbsolute
- Patients with significant hepatic dysfunctionOrgan ImpairmentRelative
- Pediatric patientsAgeRelative
- Pregnant womenReproductiveAbsolute
- Severe hepatic impairmentOrgan ImpairmentRelative
Regulatory Status
- European UnionInvestigationalEvaluated in European clinical trials; not authorized.
- United StatesInvestigationalInvestigational New Drug (IND) filed; never received FDA approval.
- United KingdomInvestigationalNo marketing authorization; used only in research settings.
Development discontinued after mixed efficacy results and safety concerns; not approved in any jurisdiction.
Evidence & Sources
No sources recorded yet.
Frequently Asked Questions
What is Valspodar?
Valspodar (PSC833) is a cyclosporine A analog developed as a selective P‑glycoprotein inhibitor to reverse multidrug resistance in cancer chemotherapy. It has been evaluated in Phase I‑II trials but never received regulatory approval.
What is Valspodar used for?
Valspodar is educationally associated with: Reversal of multidrug resistance in cancer, Improved chemotherapy efficacy in solid tumors, Improved chemotherapy efficacy in AML, Multidrug resistance reversal. Educational only — not medical advice.
How is Valspodar administered?
Recorded routes of administration: Intravenous, Oral.
What are the potential side effects of Valspodar?
Reported adverse effects include: Hypersensitivity reactions, Neurotoxicity, Hepatotoxicity (elevated transaminases), Enhanced chemotherapy toxicity (myelosuppression, neuropathy), Nausea/vomiting, Nausea and vomiting, Neurotoxicity (tremor, paresthesia), Hyperbilirubinemia / hepatotoxicity. This list is not exhaustive — consult a qualified clinician.
Who should avoid Valspodar?
Recorded contraindications: Severe hepatic impairment, Concurrent use with drugs highly dependent on CYP3A4/P-gp for clearance, Hypersensitivity to cyclosporine or its analogues. Consult a qualified clinician before use.