Safety and immunogenicity of a DNA vaccine encoding carcinoembryonic antigen and hepatitis B surface antigen in colorectal carcinoma patients.

Despite an abundance of preclinical data, relatively little is known regarding the efficacy of DNA vaccination in humans. Here, we present results from a dose-escalation clinical trial of a dual expression plasmid encoding carcinoembryonic antigen (CEA) and hepatitis B surface antigen (HBsAg) in 17 patients with metastatic colorectal carcinoma. CEA was selected as a prototypic tumor-associated self-antigen, and the HBsAg cDNA was included as a positive control for immune response to the DNA vaccine without relying upon breaking tolerance to a self-antigen. Groups of 3 patients received escalating single i.m. doses of the DNA vaccine at 0.1, 0.3, and 1.0 mg. Subsequent groups of 3 patients received three repetitive 0.3- or 1.0-mg doses at 3-week intervals. A final group of 2 patients received three repetitive 2.0 mg doses at 3-week intervals. Toxicity was limited to transient grade 1 injection site tenderness, fatigue, and creatine kinase elevations, each affecting a minority of patients in a non-dose-related manner. Repetitive dosing of the DNA vaccine induced HBsAg antibodies in 6 of 8 patients, with protective antibody levels achieved in four of these patients. CEA-specific antibody responses were not observed, but 4 of 17 patients developed lymphoproliferative responses to CEA after vaccination. No objective clinical responses to the DNA vaccine were observed among this population of patients with widely metastatic colorectal carcinoma. Nevertheless, this pilot trial has provided encouraging human immune response data in support of this vaccine technology.

Clinical experience with perindopril in patients nonresponsive to previous antihypertensive therapy: a large US community trial.

A subgroup analysis of a large US community trial was conducted to evaluate the antihypertensive efficacy and safety of perindopril, an angiotensin-converting enzyme inhibitor (ACEI), in 3159 patients who lacked blood pressure (BP) control at entry with previous antihypertensive therapy. Patients received 4 mg perindopril daily for 6 weeks. Based on physicians' assessment of BP response, the patients were then either maintained on 4 mg daily (group 1) or the dose was increased to 8 mg daily (group 2) for an additional 6 weeks. The mean baseline sitting BP was 158.2/92.9 mm Hg. Perindopril monotherapy produced a significant BP decrease from baseline of 11.6/6.5 mm Hg and 14.9/8.4 mm Hg at weeks 6 and 12, respectively. In group 1 patients, the majority of BP decrease occurred at week 6 (17.3/9.5 mm Hg) and was maintained until the end of week 12 (18.2/10.1 mm Hg). In group 2 patients, the BP decrease on the 4-mg dose was modest at week 6 by 5.2/3.1 mm Hg. However, further dose up-titration of perindopril to 8 mg resulted in a clinically significant BP decrease of 11.9/6.8 mm Hg from baseline to week 12. Significant antihypertensive effects of perindopril were also demonstrated in the special patient populations of elderly (>or=65 years), black, isolated systolic hypertension, patients with concomitant cardiovascular diseases, and patients nonresponsive to other ACEI therapy. Overall, BP control (<140/<90 mm Hg) was achieved in 40.0% of patients at week 12. Perindopril was well tolerated with cough and angioedema reported in 8.5% and 0.4% patients, respectively. Physicians assessed therapeutic response to perindopril as satisfactory in 73.8% patients who were nonresponsive to previous antihypertensive therapy. These results suggest that, in a community-based practice, perindopril monotherapy (4-8 mg/d) is an effective and safe therapeutic option in patients nonresponsive to previous antihypertensive therapy.

Immunization of colorectal cancer patients with recombinant baculovirus-derived KSA (Ep-CAM) formulated with monophosphoryl lipid A in liposomal emulsion, with and without granulocyte-macrophage colony-stimulating factor.

KSA (Ep-CAM) is highly expressed by colorectal cancers. The safety and immunologic effects of a vaccine consisting of recombinant baculovirus-derived KSA formulated with monophosphoryl lipid A (MPL) in liposomes and emulsified in mineral oil were evaluated, with and without co-administration of granulocyte-macrophage colony-stimulating factor (GM-CSF). Eleven patients with metastatic colorectal cancer received three subcutaneous (s.c.) injections of the vaccine at 4-week intervals. Six patients were randomized to also receive human recombinant GM-CSF (rGM-CSF) by subcutaneous injection daily for 4 days with each vaccination. Immunizations with and without rGM-CSF were well tolerated. Seven of the 11 patients developed significant KSA-specific cellular immune responses as assessed by lymphoproliferation and interferon-gamma (IFN-gamma) ELISPOT assays. All nine tested patients developed positive delayed type hypersensitivity reactions. Eight of the 11 patients developed KSA-specific antibody responses. The highest levels of cellular immune responses were observed in patients who received GM-CSF. Immunization with baculovirus-derived KSA formulated with monophosphoryl lipid A in liposomal emulsion is safe and can elicit KSA-specific immune responses. Co-administration of GM-CSF with this formulation is an effective method of generating KSA-specific T-helper (Th) 1-associated cellular immune responses.