RESUMEN
Aim: We report results of a first-in-human study of pasotuxizumab, a PSMA bispecific T-cell engager (BiTE®) immune therapy mediating T-cell killing of tumor cells in patients with advanced castration-resistant prostate cancer. Patients & methods: We assessed once-daily subcutaneous (SC) pasotuxizumab. All SC patients developed antidrug antibodies; therefore, continuous intravenous (cIV) infusion was assessed. Results: A total of 47 patients received pasotuxizumab (SC: n = 31, 0.5-172 µg/d; cIV: n = 16, 5-80 µg/d). The SC maximum tolerated dose was 172.0 µg/d. A sponsor change stopped the cIV cohort early; maximum tolerated dose was not determined. PSA responders occurred (>50% PSA decline: SC, n = 9; cIV, n = 3), including two long-term responders. Conclusion: Data support pasotuxizumab safety in advanced castration-resistant prostate cancer and represent evidence of BiTE monotherapy efficacy in solid tumors. Clinical trial registration: NCT01723475 (ClinicalTrials.gov).
Asunto(s)
Anticuerpos Biespecíficos , Antineoplásicos Inmunológicos , Neoplasias de la Próstata Resistentes a la Castración , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Anticuerpos Biespecíficos/inmunología , Anticuerpos Biespecíficos/farmacocinética , Anticuerpos Biespecíficos/uso terapéutico , Antígenos de Superficie/inmunología , Antineoplásicos Inmunológicos/inmunología , Antineoplásicos Inmunológicos/farmacocinética , Antineoplásicos Inmunológicos/uso terapéutico , Biomarcadores de Tumor/sangre , Complejo CD3/inmunología , Glutamato Carboxipeptidasa II/inmunología , Inmunoterapia , Infusiones Intravenosas , Inyecciones Subcutáneas , Dosis Máxima Tolerada , Neoplasias de la Próstata Resistentes a la Castración/sangre , Neoplasias de la Próstata Resistentes a la Castración/inmunología , Neoplasias de la Próstata Resistentes a la Castración/patología , Neoplasias de la Próstata Resistentes a la Castración/terapia , Resultado del TratamientoRESUMEN
T-cell-mediated processes play an essential role in the pathogenesis of several inflammatory skin diseases such as atopic dermatitis, allergic contact dermatitis and psoriasis. The aim of this study was to investigate the role of the IL-2-inducible tyrosine kinase (Itk), an enzyme acting downstream of the T-cell receptor (TCR), in T-cell-dependent skin inflammation using three approaches. Itk knockout mice display significantly reduced inflammatory symptoms in mouse models of acute and subacute contact hypersensitivity (CHS) reactions. Systemic administration of a novel small molecule Itk inhibitor, Compound 44, created by chemical optimization of an initial high-throughput screening hit, inhibited Itk's activity with an IC50 in the nanomolar range. Compound 44 substantially reduced proinflammatory immune responses in vitro and in vivo after systemic administration in two acute CHS models. In addition, our data reveal that human Itk, comparable to its murine homologue, is expressed mainly in T cells and is increased in lesional skin from patients with atopic dermatitis and allergic contact dermatitis. Finally, silencing of Itk by RNA interference in primary human T cells efficiently blocks TCR-induced lymphokine secretion. In conclusion, Itk represents an interesting new target for the therapy of T-cell-mediated inflammatory skin diseases.