Analysis of immunological and clinical data resulting from four phase I and II trials of MVA-5T4 in colorectal cancer patients

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Background: The attenuated vaccinia virus MVA has been engineered to deliver the tumor antigen 5T4 (MVA-5T4; TroVax). 5T4 is a surface glycoprotein expressed by most solid tumors. MVA-5T4 has been tested in one phase I/II and three phase II clinical trials in colorectal cancer patients. All trials demonstrated that MVA-5T4 was well tolerated when administered alone (1 trial), as adjuvant/neoadjuvant to surgery (1 trial), or in combination with chemotherapy (FOLFOX or FOLFIRI; 2 trials). We have now collated data from all four trials, determined the incidence of immune responses across trials, and looked for associations with improved survival. Methods: Patients with histologically proven CRC were recruited to 4 independent trials in which 3 to 6 vaccinations of MVA-5T4 were scheduled to be administered either as a monotherapy, as adjuvant/neoadjuvant to surgery for respectable liver metastases or alongside treatment with FOLFIRI or FOLFOX. Antibody responses specific for 5T4 and MVA were monitored by ELISA. Survival data were collated from each hospital site. Immunological and survival data were analyzed using proportional hazards regression adjusting for age and gender. Results: Survival and immunological response data were available for 73 patients (median age 63), who received a median of 5 MVA-5T4 vaccinations (range 1–6). Of 69 patients tested for antibody responses post-vaccination (4 patients had no post-vaccination blood sample available), 54 (78%) and 65 (94%) showed positive responses for 5T4 and MVA respectively. Exploratory analyses demonstrated significant associations between immune responses and overall survival across trials. Indeed, a Cox proportional hazards model showed that a doubling in the geometric mean 5T4 antibody titre (injections 1 to 3) was associated with a 19.9% reduction in relative risk, adjusted for age and gender (p<1%). Conclusions: MVA-5T4 induced 5T4-specific immune responses in the majority of patients. Although the studies described here were uncontrolled, there were encouraging signs of activity which associated with the presence of 5T4-specific immune responses.

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The impact of genetic outreach education and support to primary care on practitioner's confidence and competence in dealing with familial cancers

AIMS

To determine the level of competence and confidence in general practice in relation to the management of familial cancers and to determine the impact of providing genetic educational outreach on confidence and competence.

METHODS

Confidence and competence in dealing with familial cancers was measured using a postal questionnaire sent to all general practitioners and practice nurses in 4 geographical areas in central England. In 2 areas, genetic educational outreach was provided to 10 randomly selected practices and a matched analysis of questionnaire responses before and after intervention was done to determine the impact of the intervention.

RESULTS

Respondents were more confident in dealing with patient queries around familial breast cancer risk than those around bowel cancer. This was inconsistent with the ability to correctly assign familial risk, with 48% incorrectly assigning a high-risk categorisation to a low-risk breast cancer scenario. Respondents who had taken part in the intervention reported more confidence in dealing with issues related to the management of patient queries around bowel cancer. Following intervention, participants were more likely to report feeling confident in knowing the relevant family history to collect (72.4% of respondents from participating practices compared to 56.1% from non-participating practices; OR 2.39, p = 0.02, 95% CI 1.14-5.00) and in making a basic assessment of risk (72.4% compared to 38.9%; OR 3.65, p = 0.01, 95% CI 1.38-9.61).

CONCLUSIONS

Providing genetic educational outreach has a positive impact upon how confident primary care staff feel in dealing with patient queries over familial cancers, particularly in relation to bowel cancer. Further research is needed to explore the impact of providing this service on other relevant outcomes such as appropriateness of referrals to genetic services.

Activity of MVA 5T4 alone or in combination with either interleukin-2 (IL-2) or interferon-α (IFN) in patients (Pts) with metastatic renal cell cancer (MRCC)

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Background: MVA 5T4 consists of the highly attenuated modified Vaccinia Ankara virus containing the gene encoding the human TAA 5T4. Ninety percent or more of RCCs overexpress the 5T4 antigen. A series of clinical trials were conducted to evaluate the effectiveness of MVA 5T4 as a single agent or in combination with Interleukin-2 or Interferon Alpha 2B. Methods: Eligibility: pathologic diagnosis of clear cell or papillary RCC, progressive measurable metastases, any prior therapy, adequate physiologic parameters, Karnofsky performance status (KPS) = 80%, and no active CNS involvement. A regimen of MVA 5T4 alone or in combination with IFN or IL-2 was given. Results: A total of 41 patients received MVA 5T4 alone or in combination. 33 patients received MVA 5T4 with low dose IL-2 or IFN. 23 pts had clear cell; 12 papillary; 5 mixed clear cell; and 1 mixed papillary. 19 pts continue to receive therapy. 2 pts (both clear cell RCC) developed complete responses, 3 pts/partial responses (2 clear cell, 1 papillary) 8 pts/stable for 3+months and 6 pts are too early to be staged at this time. Median duration of therapy is 3.0+ (1+-13+) months. Conclusion: Although comparable antibody response were observed in papillary and clear cell histotypes, clear cell patients appeared to be more likely to respond in terms of clinical benefit parameters, to be presented. Of note is that preliminary analysis of clear cell patients suggests a relationship between the anti-5T4 immune response and tumor response. With the immunological potency and encouraging clinical activity, the future research will focus on the phase 3 randomized, double-blind, placebo controlled parallel group study to investigate whether MVA 5T4, added to first line standard of care therapy, prolongs the survival of patients with locally advanced or metastatic clear cell as well as studies to further optimize MVA 5T4 potency.

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Genetics Support to Primary Care Practitioners—A Demonstration Project

Primary care practitioners need to be supported by specialist genetics services to enable them to cope effectively with the expanding relevance of genetics to their patients. Genetic counselors could be effective in such a role. This exploratory project set out to improve the Primary-Tertiary interface through piloting such a service to general practice for 1 year. Tailored genetic educational outreach was delivered by a genetic counselor to ten randomly selected general practices in central England for 12 months. A range of services were provided to the practices these included facilitated genetic update sessions, a responsive advice service and referral guidelines. The service was evaluated through pre and post intervention questionnaires and via seven semi-structured interviews. This article presents a description of the development and delivery of this service and also reports on the experiences of a sample of the participants. Participants reported positive attitudes to the service and said that they had gained knowledge and confidence, as well as recognized limitations and gaps in their current knowledge. The consistent link with a specialist genetics service provided by a genetic counselor had a positive impact during the project and participants have continued to utilize the genetic counselor for advice and support with genetic patient issues since the project was completed. This is the first example of this model of service provision. Further research, utilizing a larger sample and other measures of behavioral change needs to be carried out to assess whether this model should be adopted on a wider basis.

A vaccinia-based vaccine (TroVax) targeting the oncofetal antigen 5T4 administered before and after surgical resection of colorectal cancer liver metastases: Phase II trial

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Background: Oncofetal antigen 5T4 is expressed by most colorectal cancers. Administration of a vaccine combining a Modified Vaccinia Ankara (MVA) vector with 5T4 elicits immune responses in late-stage colorectal cancer patients. This trial seeks to investigate the immunological effects of the vaccine both in peripheral blood and locally in tumour tissue resected during potentially curative surgery for colorectal liver metastases. Some patients may have micrometastatic disease, a potential target for immunotherapy. Methods: Colorectal cancer patients selected for resection of liver metastases were eligible. Recruitment of up to 20 patients was planned. Following screening they received 2 vaccinations prior to, and 2 after, surgery. Primary endpoint was assessment of the immune response at time of surgery. Blood was taken for analysis at screening and 2 weeks after each vaccination. A tumour biopsy was obtained at surgery. T-cell responses were assessed using proliferation and gamma-interferon ELISPOT assays; ELISA used to assess serological response. Immunohistochemical analysis was used to confirm tumour antigen expression and the nature of T-cell infiltration into the liver. If 5T4-specific immune responses were demonstrated patients were offered further vaccinations at 20 and 28 weeks post surgery. Results: Of 20 patients recruited, 16 were eligible for assessment, 4 excluded, 1 due to hepatocellular carcinoma, 3 with inoperable disease. There was no grade III/IV toxicity related to vaccination. Tumour expression of 5T4 was confirmed in all cases, local T-cell infiltration consisted predominantly of CD4 cells. According to proliferation assays, 8 of 16 patients had T-cell responses at time of surgery and 12 of 16 in total to date. 14 patients have developed 5T4-specific antibody responses. At median follow up of 8.4 months 7 of 16 patients have disease recurrence. Conclusions: The MVA-5T4 vaccine (TroVax) was safe and well tolerated in all patients undergoing resection of colorectal liver metastases. 5T4 specific cellular and/or humoral immune responses were induced in the majority of patients following vaccination with TroVax.

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Cardiac troponin I: evaluation of a biomarker for the diagnosis of heart disease in the dog

OBJECTIVES

To assess the value of measuring blood levels of the myocardial protein cardiac troponin I (cTnl) in the diagnosis of congenital and acquired heart disease in the dog and in the evaluation of the severity of heart failure.

METHODS

Serum samples obtained from healthy dogs (n = 26) and from dogs diagnosed with a variety of congenital and acquired heart conditions (n = 35) were assayed for cTnl concentration using an automated immunoassay method. Results were also analysed according to the degree of heart failure as assessed using the International Small Animal Cardiac Health Council's scheme.

RESULTS

Healthy dogs had very low or undetectable blood cTnl levels, as did dogs with congenital heart disease. However, cTnl levels were significantly elevated in dogs with acquired mitral valve disease, dilated cardiomyopathy and pericardial effusion. Blood cTnl levels also varied with severity of heart failure.

CLINICAL SIGNIFICANCE

Measurement of blood cTnl levels may be a useful aid in the diagnosis of dogs with suspected heart disease and in indicating the severity of heart failure.

The prevalence of chronic chest and leg pain following cardiac surgery: a historical cohort study

Chronic pain after surgery is recognised as an important post-operative complication; recent studies have shown up to 30% of patients reporting persistent pain following mastectomy and inguinal hernia repair. No large-scale studies have investigated the epidemiology of chronic pain at two operative sites following coronary artery bypass grafting (CABG). This paper reports the follow-up of a cohort of 1348 patients who underwent cardiac surgery between 1996 and 2000 at one cardiothoracic unit in northeast Scotland. Chronic pain was defined as pain in the location of surgery, different from that suffered pre-operatively, arising post-operatively and persisting beyond 3 months. The survey questionnaire consisted of the short-form-36 (SF-36), Rose angina questionnaire, McGill pain questionnaire and the University of California and San Francisco (UCSF) pain service questionnaire. Of the 1080 responders, 130 reported chronic chest pain, 100 chronic post-saphenectomy pain and 194 reported pain at both surgical sites. The cumulative prevalence of post-cardiac surgery pain was 39.3% (CI(95) 36.4-42.2%) and mean time of 28 months since surgery (SD 15.3 months). Patients who reported pain at both sites had lower quality of life scores across all eight health domains compared to patients with pain at one site only and those who were pain-free. Prevalence of chronic pain decreased with age, from 55% in those aged under 60 years to 34% in patients over 70 years. Patients with pre-operative angina and those who were overweight or obese (BMI>/=25) at the time of surgery were more likely to report chronic pain. Chronic pain following median sternotomy and saphenous vein harvesting is more common than hitherto reported and that patients undergoing CABG should be warned of this possibility.