The lag time in initiating clinical testing of new drugs in combination with radiation therapy, a significant barrier to progress?

Background:

The clinical development of new drugs with radiation appears to be limited. We hypothesised that phase I clinical trials with radiation therapy (RT) are initiated too late into a new drug's lifetime, impeding the ability to complete RT–drug development programmes before patent expiration.

Methods:

We identified novel drug–radiation phase I combination trials performed between 1980 and 2012 within the PubMed and ClinicalTrials.gov databases. Data gathered for each drug included: date the initial phase I trial with/without RT was opened/published, date of the published positive phase III trials, and patent expiration dates. Lag time was defined as the interval between opening of the phase I trial without RT and the opening of the phase I with RT. Linear regression was used to model how the lag time has changed over time.

Results:

The median lag time was 6 years. The initial phase I trial with RT was typically published 2 years after the first published positive phase III trial and 11 years before patent expiration. Using a best-fit linear model, lag time decreased from 10 years for phase I trials published in 1990 to 5 years in 2005 (slope significantly non-zero, P<0.001).

Conclusions:

Clinical drug development with RT commences late in the life cycle of anti-cancer agents. Taking into account the additional time required for late-phase clinical trials, the delay in initiating clinical testing of drug–RT combinations discourages drug companies from further pursuing RT-based development. Encouragingly, lag time appears to be decreasing. Further reduction in lag time may accelerate RT-based drug development, potentially improving patient outcomes.

Metabolic syndrome, diabetes mellitus, and the subsequent development of prostate cancer

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Background: The lifetime risk of an American man developing prostate cancer (PC) is one in six. Metabolic syndrome (MS) is a cluster of medical disorders (hypertension, dyslipidaemia, hyperglycaemia, obesity) associated with the subsequent development of diabetes mellitus (DM). DM and MS afflict 11% and 22% of US adults respectively. MS and DM are associated with disturbed lipid homeostasis, and hypogonadism. DM and MS predispose to the development of gastrointestinal and endometrial cancer. DM and MS's influence on PC is less clear; some studies have suggested that whereas DM inhibits PC, MS promotes PC development. Methods: The Bezafibrate Infarction Prevention study was a randomized trial of fibrate therapy for the secondary prevention of ischemic heart disease. Between 1990–2 15524 men and women with ischemic heart disease were screened, of whom 3090 entered the trial. 81% were male. Participants were divided into three groups according to baseline parameters: (A) those with neither MS nor DM, (B) those with MS but no DM, (C) those with DM (with or without MS). MS was defined according to ATPIII guidelines. DM was defined by medical history or fasting glucose > 125 mg/dL. Follow-up for PC incidence and all-cause mortality was obtained through the Israeli cancer registry and the Ministry of the Interior respectively. Analysis accounts for differences in age and non-cancer-related-mortality between groups. Ethics approval was obtained. Results: 1350 participants were excluded due to missing data or previous cancer diagnosis, leaving 11,541 men. Mean age at enrollment 61 years (45–74). Median follow-up was 12 years. There were 6119 (53%), 3,376 (29%), and 2,046 (18%) participants in groups A, B and C respectively. Overall there were 459 cases of PC; 298, 123 and 48 in groups A, B and C. The age adjusted PC rates were 4.30, 3.61 and 2.55 per 1,000 patient years in groups A, B and C respectively (A vs C p = 0.003). Data were also analyzed examining PC incidence as a function of ‘number of components of MS present’ after pooling groups A, B and C. Relative risk of developing PC was 1.00, 0.92, 0.90, 0.69, 0.71, and 0.33 for 0, 1, 2, 3, 4, and 5 components respectively. Conclusions: A baseline diagnosis of DM (highly significant) or MS (trend) was associated with a decreased prostate cancer rate over the subsequent 12 years.

No significant financial relationships to disclose.

Extreme leukocytosis in the emergency department

BACKGROUND

Extreme leukocytosis in the absence of haematological disease, is a topic about which little is known, although it may be associated with increased mortality among patients admitted to the intensive care department. The significance of extreme leukocytosis in patients presenting to hospital is uncertain.

AIM

To study the correlates and prognostic significance of extreme leukocytosis, in patients admitted to an emergency department.

DESIGN

Observational study.

METHODS

Consecutive adult patients with extreme leukocytosis (>25 x 10(9)/l, n=54) presenting to the emergency department of a university-affiliated hospital were compared to age-matched controls (+/-5 years) with moderate leukocytosis (12-25 x 10(9)/l, n=118) presenting to the same department. Data were collected on demographic features, emergency room findings and hospital course.

RESULTS

Patients with extreme leukocytosis were more likely to suffer from infectious disease (74% vs. 48%, p<0.01), to be hospitalized (100% vs. 80%, p<0.001), and to die (32.1% vs. 12.7%, p<0.01), and had a longer median length of stay (7.5 vs. 4.0 days, p<0.005). There was no significant difference in vital signs between the two groups.

DISCUSSION

In our patients, extreme leukocytosis appeared to be predominantly caused by infectious disease, and was associated with a high case fatality rate. The degree of leukocytosis may provide prognostic information beyond that reflected in traditional vital signs.