Open-label phase II study evaluating the efficacy and safety of two doses of pertuzumab in castrate chemotherapy-naive patients with hormone-refractory prostate cancer

PURPOSE

To determine the prostate-specific antigen (PSA) 50% decline rate within 24 weeks of starting treatment with single-agent pertuzumab in castrate patients with hormone-refractory prostate cancer (HRPC).

PATIENTS AND METHODS

Two independent Simon's two-stage designs were used to evaluate two doses of pertuzumab administered intravenously once every 3 weeks. An interim analysis of the first 23 assessable patients in the first cohort treated at 420 mg (loading dose of 840 mg) allowed termination of additional enrollment if three patients had a 50% decline in PSA after all patients had completed at least three cycles of therapy or withdrew due to insufficient therapeutic response, death, or study-related toxicity before completing three cycles. A second cohort of patients treated at 1,050 mg could be enrolled with the same design, and if more than three patients had a 50% decline in PSA, 27 more patients would be treated at 1,050 mg.

RESULTS

Sixty-eight castrate, chemotherapy-naive men with HRPC were enrolled. A total of 35 patients were treated at 420 mg; no PSA declines 50% were observed at the interim analysis and recruitment was stopped. A total of 33 patients were then treated at 1,050 mg, and no PSA declines 50% were observed at the interim analysis. Pertuzumab was well tolerated.

CONCLUSION

Pertuzumab has no clinically significant single-agent activity in castrate patients with HRPC at either of the tested dose levels. This may reflect the continued presence of significant levels of intraprostatic androgen driving androgen receptor signaling.

Neo-adjuvant and adjuvant hormone therapy for localised and locally advanced prostate cancer

BACKGROUND

Hormone therapy for early prostate cancer has demonstrated an improvement in clinical and pathological variables, but not always an improvement in overall survival. We performed a systematic review of both adjuvant and neo-adjuvant hormone therapy combined with surgery or radiotherapy in localised or locally advanced prostate cancer.

OBJECTIVES

The objective of this review was to undertake a systematic review and, if possible, a meta-analysis of neo-adjuvant and adjuvant hormone therapy in localised or locally advanced prostate cancer.

SEARCH STRATEGY

We searched MEDLINE (1966-2006), EMBASE, The Cochrane Library, Science Citation Index, LILACS, and SIGLE for relevant randomised trials. Handsearching of appropriate publications was also undertaken.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials of patients with localised or locally advanced prostate cancer, that is, stages T1-T4, any N, M0, comparing neo-adjuvant or adjuvant hormonal deprivation in combination with primary therapy (radical radiotherapy or radical prostatectomy) versus primary therapy alone were included in this review.

DATA COLLECTION AND ANALYSIS

Data were extracted from eligible studies and assessed for quality, and included information on study design, participants, interventions, and outcomes. Comparable data were pooled together for meta-analysis with intention-to treat principle.

MAIN RESULTS

Men with prostate cancer have different clinical outcomes based on their risk (T1-T2, T3-T4, PSA levels and Gleason score). However, the majority of studies included in this review did not report results by risk groups; therefore, it was not possible to perform sub-group analysis. Neo-adjuvant hormonal therapy prior to prostatectomy did not improve overall survival (OR 1.11, 95% CI 0.67 to 1.85, P = 0.69). However, there was a significant reduction in the positive surgical margin rate (OR 0.34, 95% CI 0.27 to 0.42, P < 0.00001) and a significant improvement in other pathological variables such as lymph node involvement, pathological staging and organ confined rates. There was a borderline significant reduction of disease recurrence rates (OR 0.74, 95% CI 0.55 to 1.0, P = 0.05), in favour of treatment. The use of longer duration of neo-adjuvant hormones, that is either 6 or 8 months prior to prostatectomy, was associated with a significant reduction in positive surgical margins (OR 0.56, 95% CI 0.39 to 0.80, P = 0.002). In one study, neo-adjuvant hormones prior to radiotherapy significantly improved overall survival for Gleason 2 to 6 patients; although, in two studies, there was no improvement in disease-specific survival (OR 0.99, 95% CI 0.75 to 1.32, P = 0.97). However, there was a significant improvement in both clinical disease-free survival (OR 1.86, 95% CI 1.93 to 2.40, P < 0.00001) and biochemical disease-free survival (OR 1.93, 95% CI 1.45 to 2.56, P < 0.00001). Adjuvant androgen deprivation following prostatectomy did not significantly improve overall survival at 5 years (OR 1.50, 95% CI 0.79 to 2.85, P = 0.2); although one study reported a significant disease-specific survival advantage with adjuvant therapy (P = 0.001). In addition, there was a significant improvement in disease-free survival at both 5 years (OR 3.73, 95%CI 2.30 to 6.03, P < 0.00001) and 10 years (OR 2.06, 95% CI 1.34 to 3.15, P = 0.0009). Adjuvant therapy following radiotherapy resulted in a significant overall survival gain apparent at 5 (OR 1.46, 95% CI 1.17 to 1.83, P = 0.0009) and 10 years (OR 1.44, 95% CI 1.13 to 1.84, P = 0.003); although there was significant heterogeneity (P = 0.09 and P = 0.07, respectively). There was also a significant improvement in disease-specific survival (OR 2.10, 95% CI 1.53 to 2.88, P = 0.00001) and disease-free survival (OR 2.53, 95% CI 2.05 to 3.12, P < 0.00001) at 5 years.

AUTHORS' CONCLUSIONS

Hormone therapy combined with either prostatectomy or radiotherapy is associated with significant clinical benefits in patients with local or locally advanced prostate cancer. Significant local control may be achieved when given prior to prostatectomy or radiotherapy, which may improve patient's quality of life. When given adjuvant to these primary therapies, hormone therapy, not only provides a method for local control, but there is also evidence for a significant survival advantage. However, hormone therapy is associated with significant side effects, such as hot flushes and gynaecomastia, as well as cost implications. The decision to use hormone therapy should, therefore, be taken at a local level, between the patient, clinician and policy maker, taking into account the clinical benefits, toxicity and cost. More research is needed to guide the choice, the duration, and the schedule of hormonal deprivation therapy, and the impact of long-term hormone therapy with regard to toxicity and the patient's quality of life.

Meta-analysis of neo-adjuvant androgen deprivation therapy (AD) in localised prostate cancer

4643

Background: AD before primary therapy, either prostatectomy (P) or radiotherapy (RT) is increasingly used in routine practice. Clinical trials of surgical series have shown an improvement in pathological variables but with limited survival data. A few RT studies have shown a clinical benefit. We performed a systematic review and meta-analysis to assess the true impact of NA treatment. Methods: Data from published clinical trials of patients with non-metastatic PC were extracted for quality, and included design, participants and comparisons and meta-analysis was performed for comparable data. The primary endpoint was overall survival (OS) and secondary endpoints included disease-specific, disease-free survival (DFS) and disease recurrence rates. Analysis was performed using Revman 4.2.8. For dichotomous data the odds ratio was calculated with 95% confidence interval (CI) and the results were tested for homogeneity at a significance level of p < 0.1. A fixed effects model was used if there was no evidence of heterogeneity between studies. Results: AD before P led to a significant reduction in disease recurrence (number (n) of patients 973 in 3 trials-overall odds ratio OR 0.74; 95% CI 0.55–1.0; p = 0.05). In addition there was a significant reduction of positive surgical margins (n 1802 in 8 trials-OR 0.34; 95% CI 0.27–0.42; p < 0.00001).There were no comparable data for pooled analysis of DFS or OS. The use of AD before RT resulted in a significant improvement in disease-specific survival (n 1082 in 3 trials-OR 1.37; 95% CI 1.06–1.77; p =0.02) and DFS (n 991 in 2 trials-OR 1.86; 95% CI 1.93–2.40; p < 0.00001). The data for biochemical DFS was heterogenous due to differences in definition of PSA recurrence but the overall effect was highly significant in favour of AD (n 1097 in 3 trials-OR 1.93; 95% CI 1.45–2.56 p < 0.00001). There was a trend to improvement of OS at 1, 2 and 5 years, not statistically significant. Conclusions: Despite a significant improvement in pathological variables with AD before surgery, available evidence is limited regarding a survival benefit which requires prolonged follow-up of patients. In selected patients undergoing RT, the addition of AD results in improved disease specific survival and DFS, likely improvement of biochemical DFS and trend to improvement in OS.

No significant financial relationships to disclose.

Radiation dose reduction without compromise of image quality in cardiac angiography and intervention with the use of a flat panel detector without an antiscatter grid

OBJECTIVE

To test the hypothesis that replacing the antiscatter grid with an air gap will reduce patient radiation exposure without significant compromise of image quality.

METHODS

457 patients having either uncomplicated diagnostic studies or a single vessel angioplasty (percutaneous transluminal coronary angioplasty (PTCA)) on a flat plate system (GE Innova) were studied. For two months their total dose-area product score was recorded on standard gridded images and then for two months on images made with the grid out, with an air gap used to reduce scatter. Detector magnification was reduced one step when an air gap was used to achieve the same final image size. A sample set of studies was reviewed blind by five observers, who scored sharpness and contrast on a non-linear scale.

RESULTS

The average dose-area product was significantly reduced, both in the diagnostic group (n = 276), from a mean (SD) of 26.2 (14.7) Gy.cm2 with the grid in to 16.1 (12) Gy.cm2 with the grid out (p = 0.01), and in the PTCA group (n = 181), from 48.2 (36.2) to 37 (27.5) (p = 0.01). The mean image quality scores of the gridless cohort were not significantly different from those of the gridded cohort.

CONCLUSION

With the use of a flat plate detector, air gap gridless angiography reduces the radiation dose to the patient and, in consequence, to the operator without significantly affecting image quality. It is proposed that gridless imaging should be the default technique for adults and children and in most installations.

Anti-cancer ProTides: tuning the activity of BVDU phosphoramidates related to thymectacin

Based on our wide ranging knowledge of phosphoramidate ProTides as anti-viral agents we have tuned the lead anti-cancer agent thymectacin in the ester and amino acid regions and revealed a substantial enhancement in in vitro potency versus colon and prostate cancer cell lines. Twelve analogues have been reported, with yields of 29-78%. The compounds are fully characterised and data clearly reveal the presence of two phosphate diastereoisomers, as expected, in roughly equi-molar proportions. The compounds were evaluated in tissue culture versus three different tumour cell lines, using thymectacin as the control. It is notable that minor structural modification of the parent phenyl methoxyalaninyl structure of thymectacin leads to significant enhancements in potency. In particular, replacement of the methyl ester moiety in the lead by a benzyl ester gave a 175-fold boost in potency versus colon cancer HT115. This derivative emerges as a low micromolar inhibitor of HT115 cells and a new lead for further optimisation.

A phase II trial of TIP (paclitaxel, ifosfamide and cisplatin) given as second-line (post-BEP) salvage chemotherapy for patients with metastatic germ cell cancer: a medical research council trial

This phase II trial describes the use of TIP chemotherapy (paclitaxel, ifosfamide and cisplatin) as salvage for patients with metastatic germ cell cancer (GCC) who have failed initial BEP (bleomycin, etoposide and cisplatin) chemotherapy. Patients with first relapse following BEP for metastatic GCC, confirmed by biopsy or sequentially rising markers, received four courses of TIP (paclitaxel 175 mg m⁻² day 1, followed on days 1–5 by ifosfamide 1 g m⁻² intravenously (i.v.) and cisplatin 20 mg² i.v.) at 3-weekly intervals. The primary outcome measure was response to TIP. In all, 51 patients were registered, of whom 43 were eligible for response assessment. Eight achieved complete remission (CR) and 18 a partial remission with negative markers (PR^−ve); favourable response rate (FRR=CR+PR^−ve) 60%, 95% CI (44–75%); survival at 1 year was 70% (56–84%) and failure-free survival 36% (22–50%). In the group of 26 patients meeting the ‘good-risk’ criteria described by the Memorial Hospital, the FRR was 73% (52–88%) compared with 41% (18–67%) for the 17 ‘poor-risk’ patients. These results are inferior to those previously reported for TIP in a single-centre study when it was given more intensively, at higher dose and with growth factor support. Nonetheless, TIP as described here can cure a substantial proportion of patients.

Assessment of immunological competence and SV40 specific recall immunity in malignant pleural mesothelioma

Diffuse malignant pleural mesothelioma (MPM) is the third most common lung malignancy showing rising incidence with 250,000 deaths expected from it in Western Europe over the next 35 year. The tumour is generally resistant to conventional treatment and there is urgent need for novel preventative and therapeutic measures to combat this growing public threat. Finding of SV40 DNA sequences in a high proportion (40-90%) of several series of MPM cases, and suggestion of its potential co-carcinogen role provide a rationale for the development of novel anti-MPM vaccines incorporating SV40 gene sequences or antigenic determinants. As a prelude to adopting this approach, general T cell function was examined in relatively early cases of MPM presenting for biopsy or debulking surgery. CD8+ T cell responses were studied using antigenic epitopes of common viral antigens covering a broad range of haplotypes. 74.1% (20/27) of MPM patients and 80% (8/10) of the control subjects showed T cell responsiveness to the viral peptides mix, whilst a small proportion showed SV40 specific recall immunity.

Ultimate low loss of hollow-core photonic crystal fibres

Hollow-core photonic crystal fibres have excited interest as potential ultra-low loss telecommunications fibres because light propagates mainly in air instead of solid glass. We propose that the ultimate limit to the attenuation of such fibres is determined by surface roughness due to frozenin capillary waves. This is confirmed by measurements of the surface roughness in a HC-PCF, the angular distribution of the power scattered out of the core, and the wavelength dependence of the minimum loss of fibres drawn to different scales.

A randomised trial of accelerated radiotherapy for localised invasive bladder cancer

BACKGROUND AND PURPOSE

To evaluate the efficacy and toxicity of an accelerated fractionation regimen to treat localised muscle invasive bladder cancer.

PATIENTS AND METHODS

A prospective randomised trial was undertaken in 229 patients randomised between 1988 and 1998 comparing accelerated fractionation (AF) to a dose of 60.8 Gy in 32 fractions over 26 days with conventional fractionation (CF) treating to 64 Gy in 32 fractions over 45 days. Accelerated fractionation was delivered using two fractions per day with a 6h gap between fractions and with the first daily fraction size being 1.8 Gy and the second daily fraction size being 2.0 Gy. There was a 1 week treatment gap after the first 12 fractions. Conventional fractionation was one fraction per day, 5 days per week. Eligible patients had clinical stage T2 or T3, N0 or N1, M0 transitional cell carcinoma. The primary endpoint of the trial was local control and the trial was powered to detect a 20% difference (alpha 0.05, power 90%). Secondary endpoints were toxicity and survival.

RESULTS

In the initial phase of the trial, randomisation was unequal such that in total 129 patients were randomised to accelerated fractionation and 100 to conventional fractionation. Acute toxicity was evaluable in 121 patients treated with AF and 96 patients treated with CF. RTOG grade 2 or 3 bowel toxicity was noted in 44% of AF patients compared to 26% of CF patients (P trend =0.001). Acute grade 2 or 3 bladder toxicity was seen in 35% of AF patients compared to 36% of CF patients (P=0.99). Late radiation toxicity was evaluated in patients surviving free from local recurrence at 2 years post treatment. Late radiation toxicity equivalent to RTOG grade 2 or more had occurred in 44% (95% CI 34-55%) of AF patients and in 38% (95% CI 26-49%) of CF patients (logrank over 5 years follow-up P=0.23). There was no significant difference in analysis of time to loss of local tumour control comparing the two treatment arms; local recurrence was recorded in 29 of the 100 patients treated with CF and in 41 of 129 patients treated with AF (logrank P=0.86). There was also no significant difference between the treatment arms comparing disease-free survival and overall survival. The overall survival figures at 3 years were for AF 54% (95% CI 45-63%) and for CF 47% (95% CI 36-57%). By 5 years the overall survival was 37% for AF and 40% for CF. There were two treatment related deaths, both on the AF arm of the trial.

CONCLUSIONS

This accelerated fractionation schedule did not improve on the efficacy of conventional fractionation for patients with T2 and T3 bladder cancer and accelerated fractionation was associated with increased acute bowel reactions.

Hormonal impact of the 17alpha-hydroxylase/C(17,20)-lyase inhibitor abiraterone acetate (CB7630) in patients with prostate cancer

A series of three dose escalating studies were conducted to investigate the ability of the 17α-hydroxylase/C_17,20-lyase inhibitor abiraterone acetate, to cause maximum suppression of testosterone synthesis when delivered to castrate and noncastrate males with prostate cancer. Study A was a single dose study in castrate males. Study B was a single dose study in noncastrate males and study C was a multiple dose study in noncastrate males. The drug was given orally in a once-daily dose and blood samples taken to assess pharmacokinetic (PK) parameters and hormone levels in all patients. The study drug was well tolerated with some variability in PKs. Suppression of testosterone levels to <0.14 nmol l⁻¹ was seen in four out of six castrate males treated with a single dose of 500 mg. At 800 mg given days 1–12 in noncastrate males, target suppression was achieved in three out of three patients, but a two- to three-fold increase of Luteinising Hormone (LH) levels in two out of three patients overcame suppression within 3 days. All patients in the multiple dose study developed an abnormal response to a short Synacthen test by day 11, although baseline cortisol levels remained normal. This is the first report of the use of a specific 17α-hydroxylase/_17,20-lyase inhibitor in humans. Repeated treatment of men with intact gonadal function with abiraterone acetate at a dose of 800 mg can successfully suppress testosterone levels to the castrate range. However, this level of suppression may not be sustained in all patients due to compensatory hypersecretion of LH. The enhanced testosterone suppression achieved in castrate men merits further clinical study as a second-line hormonal treatment for prostate cancer. Adrenocortical suppression may necessitate concomitant administration of replacement glucocorticoid.

Supercontinuum generation in submicron fibre waveguides

Submicron-diameter tapered fibres and photonic crystal fibre cores, both of which are silica-air waveguides with low dispersion at 532 nm, were made using a conventional tapering process. In just cm of either waveguide, ns pulses from a low-power 532-nm microchip laser generated a single-mode supercontinuum broad enough to fill the visible spectrum without spreading far beyond it.