Updated REVLIMID(R) Clinical Results Presented at the 12th International Workshop on Chronic Lymphocytic Leukemia

Celgene Corporation (NASDAQ: CELG) announced that clinical data
from two ongoing REVLIMID studies in Chronic Lymphocytic Leukemia
(CLL) were reported during the 12th International Workshop on Chronic
Lymphocytic Leukemia in London on Saturday, September 15, 2007.
Chronic Lymphocytic Leukemia is a hematological cancer that affects
approximately 75,000-100,000 people in the U.S. About 10,000 new cases
of CLL are diagnosed each year and an estimated 5,000 Americans are
expected to die of CLL this year. For the EU-5, the prevalence of CLL
is estimated to be about 70,000 people with an estimated 11,000 new
cases each year.

Asher Channan-Khan, M.D., of the Roswell Park Cancer Institute in
Buffalo, NY, enrolled 45 CLL patients, who had at least two prior
therapies. Overall response to lenalidomide monotherapy was 58%, of
whom 18% achieved a complete remission and 40% partial remission. The
median time to best response was 5.9 months with a range of 1.6-18.3
months. Median progression free survival of all enrolled patients was
19.4 months with a range of 1.2-31.8+ months. Of patients with poor
prognostic factors with 17p or 11q cytogenetic abnormality, 44% showed
a clinical response, while 30% of patients with fludarabine refractory
disease showed a clinical response.

The incidence of grade III/IV thrombocytopenia and neutropenia was
45% and 70% respectively. Fifteen percent of the patients experienced
febrile neutropenia.

Tumor flare reaction was a common non-hematologic adverse event.
The study reported grade I/II tumor flare reaction incidence of 50%
and grade III/IV was 8%. Another non-hematolgic adverse event
observed, tumor lysis syndrome, had 5% incidence of grade III/IV
occurrences.

"In our study, we have seen impressive activity with REVLIMID in
CLL patients," said Dr. Channan-Khan. "We continue to investigate the
clinical benefits of REVLIMID in CLL to find an optimal dose level to
maximize response while maintaining a clinically manageable side
effect profile."

Alessandra Ferrajoli, M.D., of The University of Texas M.D.
Anderson Cancer Center in Houston, TX studied heavily pretreated CLL
patients with progressive disease with a dose less than that explored
in the Channan-Khan trial. The overall response rate to single agent
lenalidomide among 44 patients was 34%, among which 7% of patients
achieved a complete remission, 2% achieved a nodular partial remission
and 25% achieved a partial remission. Stable disease was observed in
23% of the patients. Two complete responses and 4 partial responses
were observed in patients carrying 11q deletion abnormalities and one
partial response was observed in a patient with a 17p deletion. With a
median follow-up of 11 months, the median response duration is 12-plus
months.

Grade III/IV hematological adverse events observed in the 325
courses included neutropenia (39%), thrombocytopenia (15%) and anemia
(3%). Grade III/IV non-hematological adverse events consisted mainly
of diarrhea (2%), fatigue (1%) and tumor flare (1%). Additionally, 9
cases of pneumonia, 6 cases of fever of unknown origin and 2 cases of
PCP pneumonia were noted. One patient developed disseminated
mucormycosis that was fatal (day 22) and another patient died on day
11 of treatment from pneumonia and intracranial bleeding.

About the Trials

The IRB approved Phase II clinical trial at the Roswell Park
Cancer Institute was designed to evaluate and investigate the
therapeutic potential and safety of REVLIMID(R) oral monotherapy in
patients with relapsed or refractory CLL. Forty-five patients age
42-75 (median age 64) with relapsed or refractory CLL have been
enrolled. Sixty-four percent of patients had advanced Rai stage
disease and 35.5% had high-risk cytogenetics (17p- or 11q-deletions).
Fifty-one percent of patients had fludarabine refractory disease.
Patients in the study received 25 mg of REVLIMID orally once daily for
21 days in a four-week cycle until achievement of a complete response.
If progressive disease was observed, rituximab was added to
lenalidomide.

The study at The University of Texas M.D. Anderson Cancer Center
evaluated REVLIMID's activity in CLL in patients who had received
prior purine analog-based combinations. Forty-four patients age 49-86
(median age 64) were enrolled. The median number of prior treatments
is 5 (range 1-15) and the median beta-2-microglubulin level was 4.3
mg/dL (range 1.6-10.1). Eighty-eight percent of the patients had
unmutated IgVH genes and 59% carried a poor prognostic genomic
abnormality (17p- or 11q-deletions). Forty-five percent of patients
had advanced Rai stage disease, 27% were fludarabine refractory and
51% had received prior alemtuzumab treatment. Patients received 10mg
of REVLIMID orally once daily for four weeks, followed by dose
escalation by 5 mg every 28 days to a maximum dose of 25mg/day.

Within the EU, Switzerland, Iceland and Norway, REVLIMID(R)
(lenalidomide) is authorized for marketing and, in combination with
dexamethasone, is indicated for the treatment of multiple myeloma
patients who have received at least one prior therapy.

REVLIMID is currently approved in the United States by the U.S.
Food and Drug Administration (FDA) for multiple myeloma patients who
have received at least one prior therapy, and for treatment of
patients with transfusion-dependent anemia due to low- or
intermediate-1-risk MDS associated with a deletion 5q cytogenetic
abnormality with or without additional cytogenetic abnormalities.
REVLIMID has obtained Orphan Drug designation in the EU, US,
Switzerland and Australia for treatment of multiple myeloma, and MDS,
and, for CLL in the US.

About REVLIMID(R)

REVLIMID is an IMiDs(R) compound, a member of a proprietary group
of novel immunomodulatory agents. REVLIMID and other IMiDs compounds
continue to be evaluated in over 100 clinical trials in a broad range
of hematological and oncological conditions. The IMiDs pipeline is
covered by a comprehensive intellectual property estate of issued and
pending patent applications in the US, EU and other regions, including
composition-of- matter and use patents.

About Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia results from an acquired (not
inherited) injury to the DNA of a single cell, a lymphocyte, in the
bone marrow. This injury is not present at birth. Scientists do not
yet understand what produces this change in the DNA of CLL patients.

This change in the cell's DNA confers a growth and survival
advantage on the cell, which becomes abnormal and malignant
(leukemic). The result of this injury is the uncontrolled growth of
lymphocytic cells in the marrow leading invariably to an increase of
abnormal lymphocytes in the blood and the bone marrow. These
lymphocytes do not perform their functions as normal ones would and
interfere with the production of other blood cells necessary for the
normal functioning of the blood, leading to a host of complications
like deficiency of the immune system, coagulation problems, swollen
lymph nodes, and many other conditions.

About Celgene

Celgene Corporation, headquartered in Summit, New Jersey, is an
integrated global pharmaceutical company engaged primarily in the
discovery, development and commercialization of innovative therapies
for the treatment of cancer and inflammatory diseases through gene and
protein regulation. For more information, please visit the Company's
website at www.celgene.com.

This release contains forward-looking statements which are subject
to known and unknown risks, delays, uncertainties and other factors
not under the Company's control, which may cause actual results,
performance or achievements of the Company to be materially different
from the results, performance or other expectations expressed or
implied by these forward-looking statements. These factors include
results of current or pending research and development activities,
actions by the FDA and other regulatory authorities, and other factors
described in the Company's filings with the Securities and Exchange
Commission such as our 10K, 10Q and 8K reports.