See: http://www.arraybiopharma.com/

- Array to Receive $4 Million Milestone Payment From AstraZeneca -

BOULDER, Colo., June 14 /PRNewswire-FirstCall/ -- Array BioPharma
Inc. (Nasdaq: ARRY) has initiated a Phase I clinical trial for its
small molecule anticancer compound, ARRY-142886 (AZD6244). Array
partnered co-development and commercialization of this compound with
AstraZeneca PLC in December 2003 and is entitled to a $4 million
milestone payment for initiating the trial. Array may receive
additional development and commercialization milestones of over $81
million (dependent upon the number of successfully commercialized
products) and royalties on product sales.

The Phase I trial is designed to evaluate tolerability and
pharmacokinetics of ARRY-142886 (AZD6244) following oral
administration to patients with advanced cancer. In addition, the
trial is designed to examine patients for indications of biological
activity utilizing tumor biomarkers and pharmacodynamic measurements.
The trial is currently being conducted at a single center and may
subsequently be expanded to additional sites.

"We believe that ARRY-142886 (AZD6244) holds great promise for cancer
patients, and we look forward to further clinical progress," said
Kevin Koch, Ph.D., President and Chief Scientific Officer, Array
BioPharma. "As our first proprietary compound begins human clinical
testing, we continue to build a strong pipeline of orally active drug
candidates focused on cancer and inflammatory disease."

ARRY-142886 (AZD6244) is a novel, selective, ATP non-competitive
inhibitor of MEK 1/2 that has demonstrated nanomolar activity against
isolated MEK enzyme and numerous cancer cell lines. MEK is a critical
enzyme at the intersection of several biological pathways, which
regulates cell proliferation, survival, migration and differentiation
as part of the ras/raf/MEK/erk pathway. Oral administration of ARRY-
142886 (AZD6244) has demonstrated tumor suppressive or regressive
activity in multiple preclinical models of human cancer, including
melanoma, pancreatic, colon, lung and breast cancers