Proteolix to Present Preclinical Data on Carfilzomib and PR-957 at the 2009 ACR/ARHP Annual Meeting

Proteasome inhibition blocks immune cell signaling and reduces disease progression in mouse models of Lupus

Oct 17, 2009, 09:00 ET from Proteolix, Inc.

SOUTH SAN FRANCISCO, Oct. 17 /PRNewswire/ -- Proteolix, Inc. today announced that data from preclinical studies of carfilzomib and PR-957 will be presented at the 2009 ACR/ARHP Annual Scientific Meeting on October 16 - 21 in Philadelphia, PA. Carfilzomib is the first in a new class of selective, irreversible proteasome inhibitors, and is currently enrolling patients in multiple oncology clinical trials, including a Phase 2 study in patients with relapsed and refractory multiple myeloma. PR-957 is Proteolix's preclinical-stage selective immunoproteasome inhibitor.

Data presented at the ACR/ARHP Annual Meeting support the role for proteasome inhibition - and specifically for targeting the immunoproteasome - in the treatment of autoimmune disorders. In oral presentations on Sunday October 18th, scientists from the University of Rochester Medical Center will present data that demonstrate carfilzomib and PR-957 block inflammatory pathways underlying lupus and involved in disease progression. In multiple mouse models of systemic lupus erythematosus (SLE), carfilzomib administration on its current clinical dose schedule was effective at reducing clinical signs of disease. These effects are also induced via selective inhibition of the immunoproteasome with PR-957, extending published results that PR-957 blocks disease progression in models of rheumatoid arthritis and other autoimmune indications. On Monday Oct 19th, Proteolix scientists will present data that demonstrate PR-957 blocks human inflammatory T-cell function in vitro, further supporting the immunoproteasome as a target in autoimmune diseases. Taken together, these data provide a biologic rationale for use of proteasome inhibitors in SLE and other autoimmune disorders.

A complete list of the company's oral and poster presentations at ACR/ARHP follows:

Oral Presentations

Sunday, October 18, 2009: 2:30 p.m. ET

Location: Philadelphia Marriott Downtown, Salon H

  • Proteasome Inhibitors Block Production of Alpha Interferon and B Cell Activation (Presentation #579)

Sunday, October 18, 2009 at 5:30 p.m. ET

Plenary Session

Location: Pennsylvania Convention Center 204 B

  • Novel Proteasome Inhibitors Have a Beneficial Effect in Murine Lupus (Presentation #642)

Poster Presentations

Monday, October 19, 2009: 9:00 a.m. - 11:00 a.m. ET

Location: Pennsylvania Convention Center Hall D

  • The Selective Immunoproteasome Inhibitor PR-957 Blocks Production of Inflammatory Cytokines by Polarized Th1 and Th17 Cells without Affecting TGF-B Production by Regulatory T-Cells (Presentation #1080)

About Carfilzomib

Carfilzomib is the first in a new class of highly specific proteasome inhibitors. Carfilzomib produces specific and sustained inhibition of the proteasome, leading to apoptosis in cancer cells with minimal off-target effects. In Phase 1 and Phase 2 clinical trials, carfilzomib has demonstrated single-agent activity in hematologic and solid tumors, including multiple myeloma and renal cancer. Proteolix is currently conducting a comprehensive clinical development program evaluating carfilzomib for the treatment of multiple myeloma, including two ongoing Phase 2 clinical trials of single-agent carfilzomib, one in heavily pre-treated relapsed and refractory patients with progressive disease who have failed to respond to prior treatment, and a second in relapsed patients stratified by prior treatment with bortezomib. A Phase 1b clinical trial of carfilzomib in combination with lenalidomide and dexamethasone in patients with relapsed multiple myeloma is also ongoing. In addition, based on promising Phase 1 results, Proteolix is conducting a single-agent Phase 1b/2 clinical trial of carfilzomib in patients with recurrent or advanced solid tumors. For the latest information regarding ongoing carfilzomib clinical trials, please visit

About PR-957

PR-957 is the first highly selective, small molecule inhibitor of the immunoproteasome. The immunoproteasome is a specific form of the proteasome found in many cells of the immune system. PR-957 selectively targets a subunit of the immunoproteasome, known as LMP7 (B5i) and halts the production of cytokines associated with autoimmune inflammation. In preclinical studies, PR-957 was shown to block disease progression in mouse models of rheumatoid arthritis in a dose-dependent manner and to eliminate visible signs of disease at the highest dose.

About Proteolix

Founded in December 2003, Proteolix, Inc. is a privately-held biotechnology company, headquartered in South San Francisco, dedicated to discovering, developing and commercializing novel therapeutics that target protein degradation pathways for cancer and autoimmune diseases. Proteolix's lead product, carfilzomib, is the first in a new class of selective, irreversible proteasome inhibitors. Proteolix is also developing a pipeline of novel proteasome inhibitors, including a selective, oral proteasome inhibitor and a selective immunoproteasome inhibitor. For additional information on Proteolix, please visit

SOURCE Proteolix, Inc.