RESUMEN
PURPOSE: Cabazitaxel, used in patients with metastatic castration-resistant prostate cancer (mCRPC), is associated with adverse events which may require dose reductions or discontinuation of treatment. We investigated the potential association of single-nucleotide polymorphisms (SNPs) in genes encoding drug transporters and drug-metabolizing enzymes with cabazitaxel toxicity, overall survival (OS) and pharmacokinetics (PK). METHODS: A total of 128 cabazitaxel-treated mCRPC patients, of whom prospectively collected data on toxicity and OS were available and 24 mCRPC patients with available cabazitaxel PK measurements, were genotyped using genomic DNA obtained from EDTA blood. The SLCO1B1 (388A > G; *1B; rs2306283 and 521 T > C; *5; rs4149056 and haplotype SLCO1B1*15), SLCO1B3 (334 T > G; rs4149117), CYP3A4 (*22; rs35599367), CYP3A5 (*3; rs776746), ABCB1 (3435C > T; rs1045642), and TUBB1 (57 + 87A > C; rs463312) SNPs were tested for their association with clinical and PK parameters by univariate/multivariate logistic regression, log-rank test, or Kruskal-Wallis test. RESULTS: The SLCO1B1*15 haplotype was significantly associated with a lower incidence of leukopenia and neutropenia (p = 0.020 and p = 0.028, respectively). Patients harboring a homozygous variant for SLCO1B1*1B experienced higher rate ≥ grade 3 (p = 0.042). None of the SNPs were associated with pharmacokinetics or OS. CONCLUSIONS: In this study, SLCO1B1 (SLCO1B1*15 and SLCO1B1*1B) was associated with cabazitaxel-induced adverse events in mCRPC patients. As the associations were opposite to previous studies in other drugs and contradicted an underlying pharmacokinetic rationale, these findings are likely to be false-positive and would ideally be validated with even larger (pharmacokinetic) cohorts.
Asunto(s)
Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Polimorfismo de Nucleótido Simple/genética , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Neoplasias de la Próstata Resistentes a la Castración/genética , Taxoides/efectos adversos , Taxoides/uso terapéutico , Anciano , Supervivencia sin Enfermedad , Haplotipos/genética , Humanos , Leucopenia/inducido químicamente , Leucopenia/genética , Masculino , Persona de Mediana Edad , Neutropenia/inducido químicamente , Neutropenia/genética , Estudios Prospectivos , Neoplasias de la Próstata Resistentes a la Castración/mortalidad , Resultado del TratamientoRESUMEN
Aim: The pharmacokinetics and pharmacodynamics of vemurafenib are characterized by a wide interpatient variability. Since multiple polymorphic enzymes and drug transporters are involved in vemurafenib pharmacokinetics, we studied associations of polymorphisms on vemurafenib-associated toxicities. Patients & methods: Prospectively collected samples of 97 melanoma patients treated with vemurafenib alone (n = 62) or in combination with cobimetinib (n = 35) were genotyped for ABCB1 (3435C>T), ABCG2 (421C>A, 34G>A) and CYP3A4 (*22, 15389C>T) polymorphisms. Associations between these variants and the incidence of toxicities were studied. Results:CYP3A4*22 was significantly associated with increased risk for grade ≥3 nausea, grade 1-4 hyperbilirubinemia, and cutaneous squamous cell carcinoma. ABCB1 3435C>T was a predictor for grade ≥3 toxicity. Conclusion: Genetic variants in CYP3A4 and ABCB1 are associated with vemurafenib-associated toxicities.