Adding abiraterone or docetaxel to long-term hormone therapy for prostate cancer: directly randomised data from the STAMPEDE multi-arm, multi-stage platform protocol.

Background: Adding abiraterone acetate with prednisolone (AAP) or docetaxel with prednisolone (DocP) to standard-of-care (SOC) each improved survival in systemic therapy for advanced or metastatic prostate cancer: evaluation of drug efficacy: a multi-arm multi-stage platform randomised controlled protocol recruiting patients with high-risk locally advanced or metastatic PCa starting long-term androgen deprivation therapy (ADT). The protocol provides the only direct, randomised comparative data of SOC + AAP versus SOC + DocP. Method: Recruitment to SOC + DocP and SOC + AAP overlapped November 2011 to March 2013. SOC was long-term ADT or, for most non-metastatic cases, ADT for ≥2 years and RT to the primary tumour. Stratified randomisation allocated pts 2 : 1 : 2 to SOC; SOC + docetaxel 75 mg/m2 3-weekly×6 + prednisolone 10 mg daily; or SOC + abiraterone acetate 1000 mg + prednisolone 5 mg daily. AAP duration depended on stage and intent to give radical RT. The primary outcome measure was death from any cause. Analyses used Cox proportional hazards and flexible parametric models, adjusted for stratification factors. This was not a formally powered comparison. A hazard ratio (HR) <1 favours SOC + AAP, and HR > 1 favours SOC + DocP. Results: A total of 566 consenting patients were contemporaneously randomised: 189 SOC + DocP and 377 SOC + AAP. The patients, balanced by allocated treatment were: 342 (60%) M1; 429 (76%) Gleason 8-10; 449 (79%) WHO performance status 0; median age 66 years and median PSA 56 ng/ml. With median follow-up 4 years, 149 deaths were reported. For overall survival, HR = 1.16 (95% CI 0.82-1.65); failure-free survival HR = 0.51 (95% CI 0.39-0.67); progression-free survival HR = 0.65 (95% CI 0.48-0.88); metastasis-free survival HR = 0.77 (95% CI 0.57-1.03); prostate cancer-specific survival HR = 1.02 (0.70-1.49); and symptomatic skeletal events HR = 0.83 (95% CI 0.55-1.25). In the safety population, the proportion reporting ≥1 grade 3, 4 or 5 adverse events ever was 36%, 13% and 1% SOC + DocP, and 40%, 7% and 1% SOC + AAP; prevalence 11% at 1 and 2 years on both arms. Relapse treatment patterns varied by arm. Conclusions: This direct, randomised comparative analysis of two new treatment standards for hormone-naïve prostate cancer showed no evidence of a difference in overall or prostate cancer-specific survival, nor in other important outcomes such as symptomatic skeletal events. Worst toxicity grade over entire time on trial was similar but comprised different toxicities in line with the known properties of the drugs. Trial registration: Clinicaltrials.gov: NCT00268476.

Harnessing engineered antibodies of the IgE class to combat malignancy: initial assessment of FcɛRI-mediated basophil activation by a tumour-specific IgE antibody to evaluate the risk of type I hypersensitivity.

BACKGROUND: IgE antibodies, sequestered into tissues and retained locally by the high-affinity IgE receptor, FcɛRI, on powerful effector cells such as mast cells, macrophages and eosinophils, may offer improvements in the therapy of solid tumours. The chimeric antibody, MOv18 IgE, against the human ovarian carcinoma antigen, folate receptor α (FRα), is more effective than its IgG1 counterpart in xenograft models of ovarian cancer. Although MOv18 IgE binds to a single epitope on FRα and cannot cross-link IgE receptors on basophils, there remains a risk that components in the circulation of ovarian cancer patients might cross-link FRα-MOv18-IgE-receptor-FcɛRI complexes on basophils to cause type I hypersensitivity. OBJECTIVE: To assess the propensity for MOv18 used in a therapeutic setting to cause FcɛRI-mediated type I hypersensitivity. METHODS: As validated readouts of the potential for MOv18 to cause FcɛRI-mediated type I hypersensitivity we measured release of a granule-stored mediator from a rat basophilic leukaemia cell line RBL SX-38 stably transfected with human tetrameric (αßγ2) FcɛRI, and induction of CD63 on blood basophils from patients with ovarian carcinoma and healthy controls ex vivo. RESULTS: Serum FRα levels were increased in ovarian cancer patients compared with healthy controls. MOv18 IgE alone, or in the presence of its antigen recombinant human FRα, or of healthy volunteer (n=14) or ovarian carcinoma patient (n=32) sera, did not induce RBL SX-38 cell degranulation. Exposure to FRα-expressing ovarian tumour cells at target-to-effector ratios expected within tumours induced degranulation. MOv18 IgE did not induce expression of CD63 in blood basophils from either healthy volunteers (n=6), or cancer patients, despite detectable levels of circulating FRα (n=5). CONCLUSION AND CLINICAL RELEVANCE: These encouraging data are compatible with the hypothesis that, when ovarian carcinoma patients are treated with MOv18, FcɛRI-mediated activation of effector cells occurs within the tumour mass but not in the circulation mandating, with due caution, further pre-clinical studies.

The role of IGF-I in human skin and its appendages: morphogen as well as mitogen?

Previous studies have investigated the expression of insulin-like growth factor-I (IGF-I) and its receptor in cultured skin cells or in whole skin. In order to fully understand the role of IGF-I in the skin and its appendages, however, a comprehensive study that details the expression of IGF-I and the IGF-I receptor in sections of human skin is needed. Therefore, we now report an immunocytochemical and in situ hybridization localization study of the cell types expressing IGF-I and its receptor in human adult skin and its appendages. We have observed that (i) dermal fibroblasts produce IGF-I, (ii) the epidermal basal keratinocytes are IGF-I negative but IGF-I receptor positive, and (iii) the keratinocytes of the stratum granulosum produce IGF-I. These observations indicate either that the mitogenesis of the basal keratinocytes is regulated by IGF-I expressed both in the dermis and in the stratum granulosum, or that dermal fibroblasts are responsible for sequestering IGF-I to the basal keratinocytes and that the stratum granulosum-derived IGF-I may be an autocrine regulator of epidermal differentiation. The distribution of IGF-I and its receptor in the hair follicle indicates that IGF-I may be a morphogen, not a mitogen, at those sites, because their proliferating cells, but not their differentiating cells, are IGF-I receptor negative. Further, IGF-I receptor expression by the dermal papilla appears to be switched off during the transition from anagen to catagen, which implies a regulatory role for IGF-I during the hair growth cycle.