A virus-like particle-based anti-nerve growth factor vaccine reduces inflammatory hyperalgesia: potential long-term therapy for chronic pain.

Chronic pain resulting from inflammatory and neuropathic disorders causes considerable economic and social burden. For a substantial proportion of patients, conventional drug treatments do not provide adequate pain relief. Consequently, novel approaches to pain management, involving alternative targets and new therapeutic modalities compatible with chronic use, are being sought. Nerve growth factor (NGF) is a major mediator of chronic pain. Clinical testing of NGF antagonists is ongoing, and clinical proof of concept has been established with a neutralizing mAb. Active immunization, with the goal of inducing therapeutically effective neutralizing autoreactive Abs, is recognized as a potential treatment option for chronic diseases. We have sought to determine if such a strategy could be applied to chronic pain by targeting NGF with a virus-like particle (VLP)-based vaccine. A vaccine comprising recombinant murine NGF conjugated to VLPs from the bacteriophage Qß (NGFQß) was produced. Immunization of mice with NGFQß induced anti-NGF-specific IgG Abs capable of neutralizing NGF. Titers could be sustained over 1 y by periodic immunization but declined in the absence of boosting. Vaccination with NGFQß substantially reduced hyperalgesia in collagen-induced arthritis or postinjection of zymosan A, two models of inflammatory pain. Long-term NGFQß immunization did not change sensory or sympathetic innervation patterns or induce cholinergic deficits in the forebrain, nor did it interfere with blood-brain barrier integrity. Thus, autovaccination targeting NGF using a VLP-based approach may represent a novel modality for the treatment of chronic pain.

Immunodrugs: therapeutic VLP-based vaccines for chronic diseases.

Worldwide, the prevalence of noncommunicable chronic diseases is increasing. The use of vaccines to induce autoantibodies that neutralize disease-related proteins offers a means to effectively and affordably treat such diseases. Twenty vaccines designed to induce therapeutic autoantibodies were clinically tested in the past 12 years. Immunodrugs are therapeutic vaccines comprising virus-like particles (VLPs) covalently conjugated with self-antigens that induce neutralizing autoantibody responses. Four such VLP-based vaccines have been clinically tested and one has achieved proof of principle: a reduction of blood pressure in hypertensive patients. To facilitate preliminary clinical testing, novel nonclinical study programs have been developed. Safety study designs have considered the underlying B and T cell immunology and have examined potential toxicities of vaccine components and primary and secondary pharmacodynamic action of the vaccines.

Active immunization with IL-1 displayed on virus-like particles protects from autoimmune arthritis.

IL-1 is an important mediator of inflammation and a major cause of tissue damage in rheumatoid arthritis (RA). Therapeutic administration of recombinant IL-1 receptor antagonist (IL-1Ra) is efficacious in reducing clinical symptoms of disease, but suffers from several drawbacks, including the need for frequent administrations of large amounts. Here, we show that immunization of mice with either IL-1alpha or IL-1beta chemically cross-linked to virus-like particles (VLP) of the bacteriophage Qbeta elicited a rapid and long-lasting autoantibody response. The induced Ab efficiently neutralized the binding of the respective IL-1 molecules to their receptors in vitro and their pro-inflammatory activities in vivo. In the collagen-induced arthritis model, both vaccines strongly protected mice from inflammation and degradation of bone and cartilage. Moreover, immunization with either vaccine showed superior efficacy than daily administrations of high amounts of IL-1Ra. In the T and B cell-independent collagen Ab transfer model, immunization with the IL-1beta vaccine strongly protected from arthritis, whereas immunization with the IL-1alpha vaccine had no effect. Our results suggest that active immunization with IL-1alpha, and especially IL-1beta conjugated to Qbeta VLP, might become an efficacious and cost-effective new treatment option for RA and other systemic IL-1-dependent inflammatory disorders.

A vaccine for hypertension based on virus-like particles: preclinical efficacy and phase I safety and immunogenicity.

BACKGROUND: Despite the availability of efficacious drugs, the success of treating hypertension is limited by patients' inconsistent drug intake. Immunization against angiotensin II may offer a valuable alternative to conventional drugs for the treatment of hypertension, because vaccines induce relatively long-lasting effects and do not require daily dosing. Here we describe the preclinical development and the phase I clinical trial testing of a virus-like particle (VLP)-based antihypertensive vaccine. METHODS AND RESULTS: An angiotensin II-derived peptide was conjugated to the VLP Qbeta (AngQb). AngQb was highly immunogenic in mice and rats. To test for efficacy, spontaneously hypertensive rats (SHR) were immunized with 400 microg AngQb or VLP alone. Group mean systolic blood pressure (SBP) was reduced by up to 21 mmHg (159 +/- 2 versus 180 +/- 5 mmHg, P < 0.001), and total angiotensin II levels (antibody-bound and free) were increased ninefold (85 +/- 20 versus 9 +/- 1 pmol/l, P = 0.002) compared with VLP controls. SHR treated with the angiotensin-converting enzyme (ACE) inhibitor ramipril (1 mg/kg per day by mouth) reached an SBP of 155 +/- 2 mmHg. Twelve healthy volunteers of a placebo-controlled randomized phase I trial were injected once with 100 microg AngQb. Angiotensin II-specific antibodies were raised in all subjects (100% responder rate) and AngQb was well tolerated. CONCLUSIONS: AngQb reduces blood pressure in SHR to levels obtained with an ACE inhibitor, and is immunogenic and well tolerated in humans. Therefore, vaccination against angiotensin II has the potential to become a useful antihypertensive treatment providing long-lasting effects and improving patient compliance.

A therapeutic vaccine for nicotine dependence: preclinical efficacy, and Phase I safety and immunogenicity.

Nicotine is the principal addictive component in tobacco, and following uptake acts in the central nervous system. The smoking-cessation efforts of most smokers fail because a single slip often delivers sufficient nicotine to the brain to reinstate the drug-seeking behaviour. Blocking nicotine from entering the brain by induction of specific antibodies may be an effective means to prevent such relapses. The hapten nicotine was coupled to virus-like particles (VLP) formed by the coat protein of the bacteriophage Qb. In preclinical experiments, this Nicotine-Qb VLP (NicQb) vaccine induced strong antibody responses. After intravenous nicotine challenge, vaccinated mice exhibited strongly reduced nicotine levels in the brain compared with control mice. In a phase I study, 32 healthy non-smokers were immunized with NicQb. The vaccine was safe and well-tolerated. All volunteers who received NicQb showed nicotine-specific IgM antibodies at day 7 and nicotine-specific IgG antibodies at day 14. Antibody levels could be boosted by a second injection or the addition of Alum as an adjuvant and the antibodies had a high affinity for nicotine. These data suggest that antibodies induced by NicQb may prevent relapses by sequestering nicotine in the blood of immunized smokers.