alitretinoin and Kidney-Neoplasms

Although advanced renal-cell carcinoma (RCC) responds poorly to standard therapies, phase I-II trials have shown activity for combinations of interferon-alpha2b (IFN) with a retinoid. Alitretinoin (9-cis RA) is an endogenous retinoid with high binding affinity for both RAR and RXR receptor families. This phase I-II study enrolled 38 patients with RCC in a dose-escalation study of tolerability, pharmacokinetics (PK), and efficacy of twice daily oral 9-cis RA with subcutaneous IFN. In contrast to studies with similar doses of daily 9-cis RA, PK studies found a consistent reduction in 9-cis RA concentrations of about 50% after multiple b.i.d. doses of 30 or 50 mg/m2, independent of cotreatment with IFN. In the phase I portion, toxicities included systemic symptoms typical of IFN and biochemical abnormalities previously associated with retinoids. Two patients experienced dose-limiting toxicity at 50 mg/m2 b.i.d. of 9-cis RA, thus the recommended phase II dose was 30 mg/m2 b.i.d. One of twenty-six evaluable patients achieved a durable objective partial remission, and repeated dosing with this regimen was poorly tolerated. This combination of retinoid and interferon is not recommended for further study in RCC.

Topics: Adult; Aged; Alitretinoin; Antineoplastic Agents; Carcinoma, Renal Cell; Chemical and Drug Induced Liver Injury; Combined Modality Therapy; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Synergism; Fatigue; Female; Fever; Humans; Immunologic Factors; Interferon alpha-2; Interferon-alpha; Kidney Neoplasms; Male; Middle Aged; Nephrectomy; Pain; Recombinant Proteins; Remission Induction; Treatment Failure; Tretinoin

Renal cell carcinoma (RCC) is the most common malignant kidney tumors in adults. Von Hippel-Lindau (VHL) gene is deficient in >50% of RCC cases, but the role of VHL as a potential therapeutic target in RCC has not been well established. In the present study, 9-cis-Retinoic acid, which is a potent natural agonist of retinoid X receptors (RXRs), was found to decrease the viability of VHL-proficient RCC cells, but had little effect on VHL-deficient RCC cells. In addition, it was demonstrated that VHL transcriptionally regulated RXRα in a hypoxia-inducible factor-α independent manner. Moreover, a negative correlation was observed between the expressions of VHL and RXRα in RCC tissues. Collectively, these data indicate that VHL-proficient RCC patients may be more sensitive to treatment with 9-cis-retinoic acid, which acts by regulating RXRα expression, compared with VHL-deficient RCC patients. The findings of the present study demonstrate a novel function of VHL and highlight the potential of VHL expression as a therapeutic modality for the optimized treatment of RCC patients.

Topics: Alitretinoin; Antineoplastic Agents; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Renal Cell; Cell Line, Tumor; Cell Survival; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Kidney Neoplasms; Retinoid X Receptor alpha; Von Hippel-Lindau Tumor Suppressor Protein