OSI Pharmaceuticals Announces Submission of New Drug Application for Tarceva(R) in Japan

OSI Pharmaceuticals, Inc. (Nasdaq: OSIP) announced todaythat a New Drug Application has been submitted in Japan covering theuse of its flagship product, Tarceva(R) (erlotinib), for the treatmentof advanced or recurrent non-small cell lung cancer (NSCLC). Theapplication was submitted to the Japanese Ministry of Health, Labourand Welfare (MHLW) by Chugai Pharmaceutical, Co., Ltd., a Japaneseaffiliate to Roche, OSI's international partner for Tarceva. Tarcevais currently approved in the United States, the European Union, andapproximately 50 countries worldwide for the treatment of patientswith locally advanced or metastatic NSCLC after failure of at leastone prior chemotherapy regimen.

"We applaud our colleagues at Chugai and Roche for theircommitment to bringing this important treatment option to lung cancerpatients in Japan as quickly as possible," said Gabriel Leung,President, OSI Oncology. "We expect Japan to be among the topcountries in terms of sales potential for Tarceva, and to be a keygrowth driver for this product."

The filing is based on results of a Phase II study that confirmedthe safety and efficacy of Tarceva for Japanese patients, along withthe data from the NSCLC study BR.21, which compared Tarceva to placebofor the treatment of patients with advanced NSCLC after failure of atleast one prior chemotherapy regimen.

About Lung Cancer

According to the World Health Organization, lung cancer is themost common cancer worldwide, with 1.2 million new cases annually.NSCLC accounts for almost 80 percent of all lung cancer cases. InJapan specifically, the estimated incidence of lung cancer was about85,000 cases in 2005.

About Tarceva

Tarceva is a small molecule designed to target the human epidermalgrowth factor receptor 1 (HER1) pathway, one of the factors criticalto cell growth in NSCLC and other solid tumors. HER1, also known asEGFR, is a component of the HER signaling pathway, which plays a rolein the formation and growth of numerous cancers. Tarceva is designedto inhibit the tyrosine kinase activity of the HER1 signaling pathwayinside the cell, which may block tumor cell growth. Tarceva is theonly HER1/EGFR-targeted therapy proven to significantly prolongsurvival in second-line NSCLC as a single agent. Tarceva was approvedby the U.S. Food and Drug Administration (FDA) in November 2004.

Results from two earlier large, randomized, placebo-controlledclinical trials in first-line advanced NSCLC patients showed noclinical benefit with concurrent administration of Tarceva withdoublet platinum-based chemotherapy (carboplatin and paclitaxel orgemcitabine and cisplatin) and its use is not recommended in thatsetting.

In November 2005, the FDA approved Tarceva in combination withgemcitabine chemotherapy for the treatment of advanced pancreaticcancer in patients who have not received previous chemotherapy.Tarceva is the first drug in a Phase III trial to have shown asignificant improvement in overall survival when added to gemcitabinechemotherapy as initial treatment for pancreatic cancer. Tarceva isthe only EGFR therapy proven to significantly prolong survival infirst-line locally advanced or metastatic pancreatic cancer incombination with gemcitabine.

For Tarceva full prescribing information, please call1-877-TARCEVA or visit http://www.tarceva.com.

Tarceva Safety Profile

Tarceva has a well-established safety profile. In the BR.21 NSCLCtrial, the most common adverse reactions in patients receiving Tarcevawere rash and diarrhea. Grade 3/4 rash and diarrhea occurred in 9 and6 percent of Tarceva-treated patients, respectively. Rash and diarrheaeach resulted in discontinuation of 1 percent of Tarceva-treatedpatients. Dose reduction for rash and diarrhea was needed for 6 and 1percent of patients, respectively. Historically, there have beeninfrequent reports of serious interstitial lung disease (ILD),including fatalities, in patients receiving Tarceva for treatment ofNSCLC or other advanced solid tumors. In the pivotal trial in NSCLC,severe pulmonary reactions, including potential cases of interstitiallung disease, were infrequent (0.8 percent) and were equallydistributed between treatment arms. The overall incidence of ILD inTarceva-treated patients from all studies was approximately 0.7percent.

In the Phase III study in pancreatic cancer, the most commonadverse events reported were fatigue, rash, nausea, anorexia anddiarrhea. Rash was reported in 69 percent of patients who receivedTarceva plus gemcitabine and in 30 percent of patients who receivedgemcitabine plus placebo. Diarrhea was reported in 48 percent ofpatients who received Tarceva plus gemcitabine and in 36 percent ofpatients who received gemcitabine plus placebo. Two percent of thepatients discontinued Tarceva because of rash and 2 percent because ofdiarrhea. In addition, severe and potential fatal adverse eventsincluded interstitial lung disease-like complications, myocardialinfarction or ischemia, cerebrovascular accident, and microangiopathichemolytic anemia with thrombocytopenia.

About OSI Pharmaceuticals

OSI Pharmaceuticals is committed to "shaping medicines andchanging lives" by discovering, developing and commercializinghigh-quality and novel pharmaceutical products that extend life orimprove the quality of life for patients with cancer, eye diseases anddiabetes. The Company operates through three business teams, (OSI)Oncology, (OSI) Eyetech and (OSI) Prosidion. (OSI) Oncology is focusedon developing molecular targeted therapies designed to change theparadigm of cancer care. (OSI) Eyetech specializes in the developmentand commercialization of novel therapeutics to treat diseases of theeye. (OSI) Prosidion is committed to the generation of novel, targetedtherapies for the treatment of type 2 diabetes and obesity. OSI'sflagship product, Tarceva(R) (erlotinib), is the first drug discoveredand developed by OSI to obtain FDA approval and the only EGFRinhibitor to have demonstrated the ability to improve survival in bothnon-small cell lung cancer and pancreatic cancer patients. OSI marketsTarceva through partnerships with Genentech, Inc. in the United Statesand with Roche throughout the rest of the world. Macugen(R)(pegaptanib sodium injection) is approved in the United States andEurope for the treatment of neovascular age-related maculardegeneration. OSI commercializes Macugen in partnership with PfizerInc. For additional information about OSI, please visithttp://www.osip.com.

This news release contains forward-looking statements. Thesestatements are subject to known and unknown risks and uncertaintiesthat may cause actual future experience and results to differmaterially from the statements made. Factors that might cause such adifference include, among others, the completion of clinical trials,the FDA and other foreign review processes and other governmentalregulation, OSI's and its collaborators' abilities to successfullydevelop and commercialize drug candidates, competition from otherpharmaceutical companies, the ability to effectively market products,and other factors described in OSI Pharmaceuticals' filings with theSecurities and Exchange Commission.