EXHIBIT 99.3

((OSI)(TM) PHARMACEUTICALS LOGO)

                                                                    NEWS RELEASE

Contact:
   OSI Pharmaceuticals, Inc.                  Burns McClellan (representing OSI)
   Kathy Galante                              Jonathan Nugent (Investors)
   Director                                   Kathy Jones, Ph.D. (Media)
   Investor / Public Relations                (212) 213-0006
   631-962-2000

               OSI PHARMACEUTICALS PRESENTS DATA ON THE IMPACT OF
            SMOKING ON THE BLOOD LEVELS OF TARCEVA AT THE 96TH ANNUAL
                               MEETING OF THE AACR

MELVILLE, N.Y., APRIL 20, 2005 - OSI Pharmaceuticals, Inc. (Nasdaq: OSIP)
presented data at the 96th Annual Meeting of the American Association for Cancer
Research (AACR) showing that smoking results in a reduction in the blood levels
of Tarceva(TM) (erlotinib) following oral dosing of the drug in healthy
volunteers. Tarceva was approved by the FDA in November 2004 for the treatment
of patients with locally advanced or metastatic non-small cell lung cancer
(NSCLC) after failure of at least one prior chemotherapy regimen. The findings,
from a comparative clinical study on the effects of smoking on the
pharmacokinetics of Tarceva in healthy (non-cancer patients) smokers and
non-smokers, built upon observations made from an analysis of Tarceva exposure
in lung cancer patients enrolled in the pivotal BR.21 Phase III trial that
formed the basis of the Company's New Drug Application (NDA) for Tarceva. In the
BR.21 trial the effect of Tarceva on survival was observed in both never smokers
and smokers, however an apparently larger effect was observed in patients who
never smoked. The Company intends to pursue studies in cancer patients in order
to further explore whether an increase in Tarceva dose in smokers will result in
enhanced clinical benefit.

"We believe that effective dosing at or close to the maximum tolerated dose of
Tarceva therapy for most lung cancer patients is an important component," stated
Gabe Leung, Executive Vice President and President of Oncology at OSI
Pharmaceuticals. "This observation reported at AACR may be of fundamental
importance to the optimization of Tarceva treatment in the subset of lung cancer
patients who are smokers."

Marta Hamilton et al (abstract #6165) presented an analysis of the
exposure/effects analysis based on the trough level concentrations and the
population pharmacokinetics from the BR.21 study prior to describing the results
from the subsequent comparative clinical study in healthy volunteers. The BR.21
analysis showed that of all the factors assessed, only smoking status was
associated with potentially clinically relevant differences in Tarceva exposure.
Tarceva is extensively metabolized by liver and lung enzymes including CYP1A1
and 1A2, these enzymes are known to be induced by cigarette smoking. As stated
in the Tarceva package insert, smokers had a 24% higher rate of Tarceva
clearance resulting in a reduction in the blood levels of Tarceva. Based on
these observations a comparative study was conducted in 32 healthy male
subjects, 16 smokers and 16 non-smokers. Patients were dosed at both 150mg and
300mg of Tarceva and a full pharmacokinetic profile assessed. At the 150mg dose
smokers had approximately 36% of overall exposure to Tarceva (Area Under the
Curve or AUC of 6718 ng.h/ml vs. 18,726 ng.h/ml) as compared to non-smokers.
Further, the overall exposure achieved in studies at the 300mg dose was similar
to that of non-smokers at the 150mg dose (19,049 ng.h/ml vs. 18,726 ng.h/ml).
The authors concluded that Tarceva plasma profiles in current smokers were
consistent with the hypothesis that reduced exposure results from induction of
CYP1A1 and 1A2 enzymes and that studies in cancer patients should be conducted
in order to explore whether an increase in Tarceva exposure in smokers will
increase clinical benefit.

ABOUT TARCEVA

Tarceva is a small molecule designed to target the human epidermal growth factor
receptor 1 (HER1) pathway, which is one of the factors critical to cell growth
in non-small cell lung cancer (NSCLC). HER1, also known as EGFR, is a component
of the HER signaling pathway, which plays a role in the formation and growth of
numerous cancers. Tarceva is designed to inhibit the tyrosine kinase activity of
the HER1 signaling pathway inside the cell, which may block tumor cell growth.
Tarceva was approved by the FDA in November 2004 and by the Swiss health
authority, Swissmedic, in March 2005. Tarceva is an oral tablet indicated for
daily administration for the treatment of patients with locally advanced or
metastatic NSCLC after failure of at least one prior chemotherapy regimen.
Tarceva is the only EGFR inhibitor to have demonstrated a survival benefit in
NSCLC. Results from two earlier large, randomized, placebo-controlled clinical
trials in first-line advanced NSCLC patients showed no clinical benefit with
concurrent administration of Tarceva with doublet platinum-based chemotherapy
(carboplatin and paclitaxel or gemcitabine and cisplatin) and its use is not
recommended in that setting. Additional early-stage trials of Tarceva are being
conducted in other solid tumors.

ABOUT TARCEVA SAFETY

In the pivotal NSCLC trial, the most common adverse reactions in patients
receiving Tarceva were rash and diarrhea. Grade three/four rash and diarrhea
occurred in nine and six percent of Tarceva-treated patients, respectively. Rash
and diarrhea each resulted in discontinuation of one percent of Tarceva-treated
patients. Six and one percent of patients needed dose reduction for rash and
diarrhea, respectively. Historically, there have been infrequent reports of
serious interstitial lung disease (ILD), including fatalities,

in patients receiving Tarceva for treatment of NSCLC or other advanced solid
tumors. In the Phase III trial for NSCLC, severe pulmonary reactions, including
potential cases of interstitial lung disease, were infrequent (0.8 percent) and
were equally distributed between treatment arms. The overall incidence of ILD in
Tarceva-treated patients from all studies was approximately 0.7 percent.

ABOUT OSI PHARMACEUTICALS

OSI Pharmaceuticals is a leading biotechnology company primarily focused on the
discovery, development and commercialization of high-quality pharmaceutical
products that extend life or improve the quality of life for cancer and diabetes
patients worldwide. OSI's primary business remains oncology, but the Company has
a second business interest in the area of diabetes through its subsidiary,
Prosidion Limited, based in the United Kingdom. Tarceva(TM) (erlotinib), OSI's
flagship product, is the first drug discovered and developed by OSI to obtain
FDA approval and the only EGFR inhibitor to have demonstrated the ability to
improve survival in non-small cell lung cancer and pancreatic cancer. OSI
exclusively markets Novantrone(R) (mitoxantrone concentrate for injection) for
the approved oncology indications and markets Gelclair(R) Bioadherent Oral Gel
for the relief of pain associated with oral mucositis.

This news release contains forward-looking statements. These statements are
subject to known and unknown risks and uncertainties that may cause actual
future experience and results to differ materially from the statements made.
Factors that might cause such a difference include, among others, the completion
of clinical trials, the FDA review process and other governmental regulation,
OSI's and its collaborators' abilities to successfully develop and commercialize
drug candidates, competition from other pharmaceutical companies, the ability to
effectively market products, and other factors described in OSI Pharmaceuticals'
filings with the Securities and Exchange Commission.

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