Fully Human Antibody Eradicates Established Tumors as Monotherapy
FREMONT, Calif., March 15, 1999 -- Abgenix, Inc. (Nasdaq: ABGX) reported today in Cancer Research (Volume 59, Issue no. 6), encouraging results of preclinical studies with its proprietary fully human monoclonal antibody, ABX-EGF. Developed using the company's XenoMouseTM technology, ABX-EGF targets the receptor for human epidermal growth factor (EGFr) which is overexpressed on many major human tumor types including renal, prostate, colorectal, head and neck, and breast. As reported in a paper titled, "Eradication of Established Tumors by a Fully Human Monoclonal Antibody to the Epidermal Growth Factor Receptor without Concomitant Chemotherapy," Abgenix scientists demonstrated that ABX-EGF alone, in mouse models, can both block the growth of human tumors, is potent at comparatively low doses and, more importantly, eradicates established tumors. Another member of the EGFr family, Her-2, is the target for a monoclonal antibody currently being marketed by Genentech, Inc. for treatment of breast cancer.
With cancer cells, expression of EGFr is significantly increased, which increases growth stimuli and causes cells to divide abnormally. Consequently, many cancer cells require EGFr for their survival. ABX-EGF binds with high affinity to the EGFr and selectively targets these cancer cells by blocking the binding of important tumor growth factors to the receptor. A key finding of the Abgenix studies was that relatively low doses of ABX-EGF, without concomitant chemotherapy, could eradicate human tumors with a size of up to 1.2cm3 in mice. Although the treatment period was relatively short, no recurrence of tumors was seen in these mice out to 250 days after the last dose of antibody. Abgenix plans to begin clinical trials with ABX-EGF around midyear.
"We believe that these results indicate the potential of ABX-EGF as a monotherapy for the treatment of multiple EGF-dependent human solid tumors, including those for which no effective chemotherapy is available," stated R. Scott Greer, president and chief executive officer of Abgenix. "Because EGFr is overexpressed on many types of cancer, ABX-EGF has the potential to be a broad cancer treatment."
As a fully human antibody generated with XenoMouseTM technology, ABX-EGF is expected to have minimal immunogenicity and a longer half-life than antibody products containing mouse protein, thus potentially allowing repeat administration at lower doses in patients with competent immune systems. This potential was observed in a Phase I clinical trial in psoriasis of ABX-IL8, the first fully human antibody generated in transgenic mice to be tested in humans. ABX-IL8 demonstrated a three week half life, equivalent to that of naturally occuring human antibodies and no immune reaction to ABX-IL8 was observed.
Abgenix is a biopharmaceutical company that develops and intends to commercialize antibody therapeutic products for the treatment of a variety of disease conditions, including transplant-related diseases, inflammatory and autoimmune disorders, cardiovascular disease and cancer. Abgenix has developed XenoMouse technology, which it believes enables quick generation of high affinity, fully human antibody product candidates to essentially any disease target appropriate for antibody therapy. Abgenix has collaborative arrangements with multiple pharmaceutical and biotechnology companies involving its XenoMouse technology. In addition, Abgenix has four proprietary antibody product candidates that are under development internally, two of which are in human clinical trials.
Statements made in this press release about the potential of ABX-EGF as a monotherapy, Abgenix's XenoMouse technology, product development activities and collaborative arrangements other than statements of historical fact, are forward looking statements and are subject to a number of uncertainties that could cause actual results to differ materially from the statements made, including risks associated with the success of clinical trials, the progress of research and product development programs, the regulatory approval process, competitive products, future capital requirements and the extent and breadth of Abgenix's patent portfolio. Please see Abgenix's public filings with the Securities and Exchange Commission for information about risks which may affect Abgenix.
Journal
Cancer Research