ARIAD Announces Results of Preclinical Studies on AP32788 at the Annual Meeting of the American Association for Cancer Research

First Presentation of Preclinical Data Supports Upcoming Clinical Testing in Non-Small Cell Lung Cancer Patients with EGFR and HER2 Exon 20 Mutations

CAMBRIDGE, Mass. & NEW ORLEANS--()--ARIAD Pharmaceuticals, Inc. (NASDAQ: ARIA) today announced the results of comprehensive preclinical studies on its investigational tyrosine kinase inhibitor (TKI), AP32788, at the American Association for Cancer Research (AACR) Annual Meeting 2016. AP32788 is a TKI designed to target specific mutations in EGFR or HER2 present in a subset of patients with non-small cell lung cancer (NSCLC), for whom there are currently no targeted therapies available. The Phase 1/2 clinical trial of AP32788 is expected to begin patient enrollment in the second quarter of 2016.

The data presented were included in an oral presentation entitled, “AP32788, a potent, selective inhibitor of EGFR and HER2 oncogenic mutants, including exon 20 insertions, in preclinical models.” The research conducted by ARIAD scientists showed that in a matched set of engineered cell lines, AP32788 inhibited all tested EGFR and HER2 mutants, including exon 20 insertion mutants, with selectivity over wild-type (WT) EGFR. Inhibition of WT EGFR in non-tumor cells has been associated with dose-limiting toxicities of EGFR inhibitors in patients. Enzymatic analysis confirmed that AP32788 irreversibly inactivated EGFR exon 20 with 20-fold selectivity over WT EGFR, in contrast to other tested EGFR TKIs. AP32788 also induced tumor regressions in a mouse EGFR exon 20 model at doses that were well tolerated.

“These preclinical data on AP32788 demonstrate its potential to potently inhibit exon 20 mutant forms of EGFR and HER2, that are not addressed by currently available TKI treatments,” said Timothy P. Clackson, Ph.D., president of research and development and chief scientific officer at ARIAD. “The selectivity data suggest that efficacious levels of exposure to AP32788 may be achievable in patients with these challenging mutations —a hypothesis we will be testing in the Phase 1/2 trial. We believe AP32788 is the first TKI that has been designed and optimized to inhibit the underlying mutation present in these orphan oncology disease subsets.”

About Non-Small Cell Lung Cancer, EGFR and HER2

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer, accounting for approximately 85 percent of the estimated 221,200 new cases of lung cancer diagnosed in 2015 in the United States, according to the American Cancer Society. EGFR mutations represent the largest known, targetable subset of NSCLC. While the most common types of EGFR mutation are addressed by approved TKI therapies, there are no targeted treatment options available for the approximately 4 to 9 percent of EGFR-mutated lung tumors with exon 20 insertion mutations1. In addition, patients with HER2 mutations, mostly exon 20 insertion mutations, comprise approximately 2 percent of NSCLC patients2 and also have no current treatment options. ARIAD estimates that there are approximately 6,000 patients in the United States living with EGFR exon 20 or HER2 point mutations, based on available data from 2014 on the number of Stage IIIB or IV NSCLC and the estimated percentage of patients with these mutations.

About AP32788

AP32788 is an investigational oral tyrosine kinase inhibitor (TKI) of activating mutations in EGFR and HER2. The molecule was designed to address the unmet need in patients with non-small cell lung cancer (NSCLC) driven by exon 20 insertion mutations in EGFR and HER2, and is ARIAD’s fourth internally discovered oncology IND to be cleared for clinical development.

About ARIAD

ARIAD Pharmaceuticals, Inc., headquartered in Cambridge, Massachusetts and Lausanne, Switzerland, is an orphan oncology company focused on transforming the lives of cancer patients with breakthrough medicines. ARIAD is working on new medicines to advance the treatment of various forms of chronic and acute leukemia, lung cancer and other difficult-to-treat orphan cancers. ARIAD utilizes computational and structural approaches to design small-molecule drugs that overcome resistance to existing cancer medicines. For additional information, visit http://www.ariad.com or follow ARIAD on Twitter (@ARIADPharm).

Forward-Looking Statements

This press release contains forward-looking statements, each of which are qualified in their entirety by this cautionary statement. Any statements contained herein which do not describe historical facts, including, but not limited to our statements about the timing of expected patient enrollment in the Phase 1/2 clinical trial of AP32788 and the statements made by Dr. Clackson, are forward-looking statements that are based on management’s expectations and are subject to certain factors, risks and uncertainties that may cause actual results, outcome of events, timing and performance to differ materially from those expressed or implied by such statements. These factors, risks and uncertainties include, but are not limited to, our ongoing strategic review, our ability to successfully commercialize and generate profits from sales of Iclusig and our product candidates, if approved; competition from alternative therapies; our ability to meet anticipated clinical trial commencement, enrollment and completion dates and regulatory filing dates for our products and product candidates and to move new development candidates into the clinic; our ability to execute on our key corporate initiatives; regulatory developments and safety issues, including difficulties or delays in obtaining regulatory and pricing and reimbursement approvals to market our products; our reliance on the performance of third-party manufacturers and specialty pharmacies for the supply and distribution of our products and product candidates; the occurrence of adverse safety events with our products and product candidates; the costs associated with our research, development, manufacturing, commercialization and other activities; the conduct, timing and results of preclinical and clinical studies of our products and product candidates, including that preclinical data and early-stage clinical data may not be replicated in later-stage clinical studies; the adequacy of our capital resources and the availability of additional funding; the ability to satisfy our contractual obligations, including under our leases, convertible debt and royalty financing agreements; patent protection and third-party intellectual property claims; litigation; our operations in foreign countries; risks related to key employees, markets, economic conditions, health care reform, prices and reimbursement rates; and other risk factors detailed in our public filings with the U.S. Securities and Exchange Commission, including our most recent Annual Report on Form 10-K and subsequent Quarterly Reports on Form 10-Q. Except as otherwise noted, these forward-looking statements speak only as of the date of this press release and we undertake no obligation to update or revise any of these statements to reflect events or circumstances occurring after this press release. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release.

1 Costa, D. 2015. EGFR Exon 20 Insertion in Non-Small Cell Lung Cancer. My Cancer Genome http://www.mycancergenome.org/content/disease/lung-cancer/egfr/64/http://www.mycancergenome.org/content/disease/lung-cancer/egfr/64/ (Updated November 5, 2015).

2 JCO April 22, 2013 JCO.2012.45.6095

Contacts

ARIAD Pharmaceuticals, Inc.
For Investors
Maria Cantor, 617-621-2208
Maria.cantor@ariad.com
or
For Media
Liza Heapes, 617-621-2315
Liza.heapes@ariad.com

Contacts

ARIAD Pharmaceuticals, Inc.
For Investors
Maria Cantor, 617-621-2208
Maria.cantor@ariad.com
or
For Media
Liza Heapes, 617-621-2315
Liza.heapes@ariad.com