Growth inhibition of an established A431 xenograft tumor by a full-length anti-EGFR antibody following gene delivery by AAV

Abstract

Therapeutic monoclonal antibodies continue to achieve clinical success for the treatment of many different diseases, particularly cancer. However, the production and purification of antibodies continues to be a time and labor-intensive process with considerable technical challenges. Gene-based delivery of antibodies may address this, via direct production within the host that achieves therapeutic levels. In this report, we validate the feasibility that gene-based delivery is a viable approach for efficacious delivery of antibodies in the preclinical and, presumably, clinical setting. We demonstrate high and sustained in vivo expression of the murine antihuman epidermal growth factor receptor antibody 14E1 following intramuscular delivery by adeno-associated virus (AAV) 2/1. Incorporating the Furin/2A technology for monocistronic expression of both heavy and light chains, we achieved sustained serum levels of full-length 14E1 peaking over 1 mg ml À1 in athymic nude mice. In the A431 xenograft tumor model, 14E1was capable of significantly inhibiting tumor growth and prolonging survival when AAV was administered prior to tumor challenge. Furthermore, 14E1 demonstrated significant antitumor efficacy against well-established tumors (B400 mm 3 ) when AAV was administered up to 20 days after tumor challenge. Here we demonstrate for the first time growth inhibition of a well-established tumor by a full-length antibody following delivery by AAV.

Recombinant Adeno-Associated Virus-Mediated Expression of Methamphetamine Antibody Attenuates Methamphetamine-Induced Hyperactivity in Mice

“…This finding is consistent with previous reports that combination of 2A self-processing system and AAV-mediated gene transfer can achieve long-term stable expression of full-length antigen-specific antibodies in the periphery for the treatment of cancers and Alzheimer’s disease in rodent models232425. The MethAb, generated by hybridoma cell lines, has high selectivity to Meth without cross-reactivity with a broad range of small molecules26.…”

Oncolytic Adenovirus Expressing Monoclonal Antibody Trastuzumab for Treatment of HER2-Positive Cancer

“…In such approaches, nontarget organs are used for production of an antibody into the systemic circulation, from which it must diffuse into tumors, just like with systemic delivery. In addition, these attempts have been hampered by low transduction, short-term expression, and/or immunological eradication of input virus, thus resulting in low antibody levels, including those found in the tumor (20)(21)(22)(23). Moreover, highdose viral transduction of the liver is not without its risks (41).…”

“…To date, gene therapy approaches featuring monoclonal antitumor antibodies have focused on production of antibodies from normal cells (20)(21)(22)(23). Meanwhile, it has remained unknown whether full-length antibodies can be produced directly from cancer cells because antibody production in humans is normally restricted to plasma cells (24).…”

Adeno-associated virus (AAV) vectors in cancer gene therapy

“…Ho et al [179] delivered 14E1, a murine antihuman epidermal growth factor (EGFR) antibody, by intramuscular administration of AAV1 vectors in the A431 human vulvar carcinoma xenograft model. Administration of vector prior to tumor cell xenografting completely inhibited or reduced tumor growth by 93% when administered 28 days before and 1 day after tumor cell implantation, respectively.…”