Product Candidate: IDEC-114 (anti-CD80)

IDEC-114 is a PRIMATIZED® anti-CD80 (anti-B7-1) monoclonal antibody that selectively targets an important co-stimulatory molecule on antigen-presenting cells. The antibody inhibits the binding of the B7-1 ligand on antigen-presenting cells to the CD28 receptor on T cells, thus blocking the second signal for inflammatory T-cell activation. In addition, B7 is expressed on activated T cells in psoriatic skin lesions rendering them direct targets for this antibody.

Inappropriately activated T cells are implicated in many autoimmune disorders, making IDEC-114 potentially useful in a wide variety of disease states.

Ex-U.S. Marketing Rights Update
In October 2001 IDEC entered into an extension of its collaborative agreement with Mitsubishi Pharma Corporation to support clinical development of IDEC-114 in psoriasis. Financial terms of the collaborative agreement are valued at approximately $35 million, subject to the attainment of product development objectives.

Under the terms of the collaborative agreement Mitsubishi Pharma will share in the costs of the clinical development of IDEC-114, and will also conduct parallel clinical trials in psoriasis in Japan. Under the terms of an existing license agreement IDEC has granted Mitsubishi Pharma an exclusive license in Asia to develop and commercialize anti-CD80 (anti-B7) antibody products. Mitsubishi Pharma will pay IDEC royalties on sales of anti-CD80 (anti-B7) antibody products in Mitsubishi Pharma’s exclusive territories.

Clinical Trial Update
In March 2001 at the 59th Annual Meeting of the American Academy of Dermatology in Washington, DC, IDEC presented results of its Phase I/II trial of IDEC-114, a PRIMATIZED® anti-CD80 (anti-B7-1) monoclonal antibody in patients with moderate to severe psoriasis.

In this study, 35 patients received four infusions of IDEC-114 at a variety of dosage levels. Clinical activity was seen in most dosage groups, along with an encouraging safety profile. The principal investigator, Alice Gottlieb, M.D., Ph.D., reported that 14 of 35 patients (40%) achieved a clinical endpoint of at least a 50% reduction in the Psoriasis Area and Severity Index (PASI) at some point in the study and 57% of patients achieved a Physician’s Global Psoriasis Assessment (PGA) of Good or above. Importantly, patients continued to improve beyond the end of the treatment period, Study Day 43. Maximum clinical improvements in PASI scores were seen on the last follow-up day, Study Day 127. The majority of adverse events were mild in severity, such as uncomplicated colds, transient chills and mild fatigue.

These are encouraging results, given the long duration of the observed response and the relatively short course of therapy. IDEC has launched two separate Phase II clinical trials in IDEC-114, each investigating different doses and schedules.