– BGB-283 Phase Ia data demonstrates activity against K-RAS and N-RAS mutations not currently targeted by first generation B-RAF inhibitors –

BEIJING, China I July 14, 2015 I BeiGene, Ltd., an innovative oncology company focused on developing targeted and immune-oncology therapeutics, today announced it has dosed the first patient in a Phase Ib clinical trial for BGB-283, a second generation B-RAF inhibitor. This study is designed to determine the efficacy of a once daily oral dosing regimen for BGB-283 in solid tumors that harbor B-RAF mutations and/or aberrations in the RAS-MAPK (mitogen-activated protein kinase) pathway. The study is being conducted across multiple centers in Australia and New Zealand.

The Phase Ib study being undertaken by BeiGene follows the successful completion of a Phase Ia dose escalation study in patients who have B-RAF or K-RAS mutations. In this study, BGB-283 demonstrated a good safety profile along with promising early clinical activity in patients harboring mutations that previously could not be targeted by first generation B-RAF inhibitors.

“We have continued to make great progress across all our clinical development programs,” commented John Oyler, the CEO of BeiGene. “BGB-283 is a clinically differentiated B-RAF inhibitor able to hit multiple important mutations in the RAS-MAPK pathway. The data from the Phase Ia dose escalation study gave us confidence to move into a broad Phase Ib study that is designed to demonstrate BGB-283’s single agent activity across a wide range of solid tumors.”

About BGB-283

First generation B-RAF inhibitors including vemurafenib and dabrafenib selectively target mutant B-RAFV600E and have exhibited remarkable clinical activities in melanoma patients with the B-RAFV600E mutation. They are approved for the treatment of patients with B-RAFV600E metastatic melanoma. However, first generation B-RAF inhibitors have limited clinical activity outside of melanoma with B-RAFV600E mutation (1-4). For example, the clinical response among CRC patients with B-RAFV600E mutations is much lower than that observed in melanoma patients.(5) BGB-283 is a second generation B-RAF inhibitor with unique RAF dimer and EGFR inhibiting activity. BGB-283 shows promising antitumor activities in preclinical models for not only cancers with B-RAF V600E mutation but also non-V600E B-RAF mutation and K-RAS/N-RAS mutations.

About BeiGene

BeiGene is an innovative oncology R&D company focused on immune-oncology therapeutics. With a team of 170+ scientists and staff, working from their Beijing based R&D facility; BeiGene’s pipeline is comprised of novel oral small molecules and monoclonal antibodies for cancer. BeiGene is working to create combination solutions that will have both a meaningful and lasting impact on cancer patients. For more information, please visit our website at www.beigene.com.

References:

1. Sosman JA, Kim KB, Schuchter L, Gonzalez R, Pavlick AC, Weber JS, et al. Survival in BRAF V600–Mutant Advanced Melanoma Treated with Vemurafenib. New England Journal of Medicine. 2012;366:707-14.

2. Anforth R, Fernandez-Penas P, Long GV. Cutaneous toxicities of RAF inhibitors. The Lancet Oncology. 2013;14:e11-e8.

3. Anforth RM, Blumetti TCMP, Kefford RF, Sharma R, Scolyer RA, Kossard S, et al. Cutaneous manifestations of dabrafenib (GSK2118436): a selective inhibitor of mutant BRAF in patients with metastatic melanoma. British Journal of Dermatology. 2012;167:1153-60.

4. Chapman PB, Hauschild A, Robert C, Haanen JB, Ascierto P, Larkin J, et al. Improved Survival with Vemurafenib in Melanoma with BRAF V600E Mutation. New England Journal of Medicine. 2011;364:2507-16.

5. Kopetz S, Desai J, Chan E, Hecht J, O’dwyer P, Lee R, et al. PLX4032 in metastatic colorectal cancer patients with mutant BRAF tumors. J Clin Oncol. 2010;28:3534.

SOURCE: BeiGene