First Phase III Trial With Definitive Results in Advanced Medullary Thyroid Cancer Shows Statistically Significant Extension of Progression Free Survival for Patients

LONDON, June 7, 2010 - Results from ZETA, a phase III study in
patients with advanced medullary thyroid cancer (MTC), showed that treatment
with the investigational drug vandetanib significantly extended Progression
Free Survival (PFS), the primary endpoint of the study, by demonstrating a
54% reduction in the rate of progression compared to placebo (HR=0.46,
p=0.0001). The results of the ZETA study were presented today at the American
Society of Clinical Oncology (ASCO) annual meeting in Chicago.

ZETA was a phase III, randomised, double-blind, placebo-controlled,
multi-centre study, evaluating oral once-daily vandetanib 300mg in 331
patients with unresectable, locally advanced or metastatic hereditary or
sporadic medullary thyroid cancer and the presence of a measurable tumour.
This was the first phase III trial with definitive results, carried out for
patients with advanced MTC.

Significant differences for vandetanib compared to placebo were also
observed in secondary endpoints of objective response rate and disease
control rate–the response rate in patients receiving vandetanib was 45%.
Patients receiving vandetanib also had a significant decrease in calcitonin
and CEA biomarkers. Overall survival (OS) data at the time of presentation
was immature.

The most common adverse events associated with vandetanib in this study,
included rash, diarrhoea, hypertension, fatigue and headache (incidence >20%
overall). The incidence of protocol-defined QTc prolongation was 8%. The
safety profile of vandetanib in this study was similar to what has been
previously observed in other studies in medullary thyroid and non small cell
lung cancer.

"Patients with advanced medullary thyroid cancer currently have few or no
options for treatment once they reach this late stage of their disease", said
Peter Langmuir, M.D. Executive Director, Medical-Science, AstraZeneca. "Given
the results of this trial, we are moving quickly to file regulatory
submissions for approval with the FDA and the EMA."

Vandetanib 300mg has orphan drug designation in the US and Europe for the
treatment of patients with advanced medullary thyroid cancer and AstraZeneca
plans regulatory submissions in 2010. Vandetanib is thought to work by
inhibition of the vascular endothelial growth factor (VEGF) pathway,
epidermal growth factor receptor (EGFR) and rearranged during transfection
(RET) pathways.

About Vandetanib

Vandetanib blocks the development of tumour blood supply by inhibition of
the VEGF pathway, and by inhibiting the growth and survival of the tumour
through EGFR and RET pathways.

About AstraZeneca

AstraZeneca is a global, innovation-driven biopharmaceutical business
with a primary focus on the discovery, development and commercialisation of
prescription medicines. As a leader in gastrointestinal, cardiovascular,
neuroscience, respiratory and inflammation, oncology and infectious disease
medicines, AstraZeneca generated global revenues of US $32.8 billion in 2009.
For more information please visit: www.astrazeneca.com.

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