Managing Expectations in the Transition to Proof of Concept Studies.

Background: As we move away from the traditional chemotherapy era to targeted therapy, the validity of old assessment paradigms associated with therapeutics are being raised in the context of immunotherapy. The old paradigm required elaborating on the toxicity assessment, with no expectation of efficacy in early phase trials. Safety data from Phase 1 and 2 studies with many immunotherapeutics show limited toxicities and draw attention to the need to demonstrate efficacy in the early evaluation of new agents.

Antibodies: At The Nexus of Antigens and Cancer Vaccines.

This review describes the development of monoclonal antibodies and the inception of their use in cancer therapy, their impact on defining cancer biomarkers, and their structural utility in new cancer vaccine development.

Plant-derived EpCAM antigen induces protective anti-cancer response.

Immunotherapy holds great promise for treatment of infectious and malignant diseases and might help to prevent the occurrence and recurrence of cancer. We produced a plant-derived tumor-associated colorectal cancer antigen EpCAM (pGA733) at high yields using two modern plant expression systems. The full antigenic domain of EpCAM was efficiently purified to confirm its antigenic and immunogenic properties as compared to those of the antigen expressed in the baculovirus system (bGA733).

Plant-derived anti-Lewis Y mAb exhibits biological activities for efficient immunotherapy against human cancer cells.

Although current demands for therapeutic mAbs are growing quickly, production methods to date, including in vitro mammalian tissue culture and transgenic animals, provide only limited quantities at high cost. Several tumor-associated antigens in tumor cells have been identified as targets for therapeutic mAbs. Here we describe the production of mAb BR55-2 (IgG2a) in transgenic plants that recognizes the nonprotein tumor-associated antigen Lewis Y oligosaccharide overexpressed in human carcinomas, particularly breast and colorectal cancers.

Inhibition of tumor growth by plant-derived mAb.

The tumor-associated antigen EpCAM (GA733-2) is a highly expressed target on adenocarcinoma cells, as defined by murine mAb CO17-1A. We recently developed a transgenic plant system for the safe and inexpensive production of large quantities of mAb CO17-1A as a future source of clinical-grade protein. Although the glycosylation pattern of plant-derived mAb (mAb(P)) CO17-1A differs considerably from that of the mammalian-derived mAb (mAb(M)), we show here that the biological activity of both mAbs is quite similar.

Simultaneous radiotherapy and radioimmunotherapy of malignant gliomas with anti-EGFR antibody labelled with iodine 125. Preliminary results.

Background: In this paper we present the preliminary results of a prospective trial of the efficacy of simultaneous radiotherapy and anti-EGFR (125)I radioimmunotherapy of malignant gliomas with 2 years' total survival as the end-point, raising the question whether anti-EGFR (125)I radioimmunotherapy influences the disease-free survival in these patients.

Material And Methods: Patients with anaplastic astrocytoma or primary glioblastoma were previously treated by a macroscopically radical neurosurgical approach and randomized either to radiotherapy + radioimmunotherapy arm or treated by radiotherapy alone. Seven patients were included in the group with radioimmunotherapy, among them five with GBM and two with AA, and five patients in the control arm.

Immunization with a plant-produced colorectal cancer antigen.

Cancer vaccination has become an important focus of oncology in recent years. Active immunization with tumor-associated antigens such as colorectal cancer antigen GA733-2 is thought to potentially overcome the reoccurrence of metastasis. As recombinant protein production in bioreactors is costly and subject to growing safety concerns, we tested plants as an alternative for the expression of a potential colorectal cancer vaccine.