Follow-up Results of Phase 2 Study of Investigational Agent, Ibrutinib, Suggest High and Durable Responses in

   Follow-up Results of Phase 2 Study of Investigational Agent, Ibrutinib,
Suggest High and Durable Responses in Relapsed/Refractory Mantle Cell Lymphoma

Data Presented at American Society of Hematology Annual Meeting

PR Newswire

ATLANTA, Dec. 11, 2012

ATLANTA, Dec. 11, 2012 /PRNewswire/ -- Pharmacyclics, Inc. (NASDAQ: PCYC)
today announced follow-up findings from an ongoing, open-label, Phase 2,
single-agent study suggesting that in patients with relapsed or refractory
mantle cell lymphoma (MCL), both those who were bortezomib-naive and
bortezomib-exposed, the investigational oral agent ibrutinib (PCI-32765)
resulted in high and durable responses and was generally well tolerated. In
the study, 111 patients received ibrutinib and 110 were evaluable for
efficacy. The median follow-up time was 9.2 months, with a range of time to
response to treatment of 1.4 to 16.4 months.

The results were presented by lead investigator Michael L. Wang, M.D.,
associate professor in the Department of Lymphoma and Myeloma at The
University of Texas MD Anderson Cancer Center, at the 54th Annual Meeting of
theAmerican Society of Hematology(ASH) in Atlanta, Ga. The study showed an
overall response rate (ORR) of 68 percent, including a complete response (CR)
of 22 percent and a partial response (PR) of 46 percent with a median
progression free survival (PFS) estimated at 13.9 months. Results were similar
between the bortezomib-naive and bortezomib-exposed patients.

Long-term follow up of the initial 51 patients enrolled in this study that
were presented last year at ASH shows there was an incremental improvement in
the response rate over time. The ORR increased for this patient subset from 69
percent in 2011 to an ORR of 75 percent in 2012, with the CR increasing from
16 percent to 39 percent over the same period.

"Now with a larger number of patients studied, we see the overall response
rate remains durable and the safety profile continues to appear manageable,"
said Dr. Wang. "In addition, what is particularly encouraging is that with
longer follow-up there is an incremental increase in the number of patients
who achieve complete response."

Relapsed MCL means the disease has returned after an initial partial or total
remission. Refractory MCL refers to cancer that does not respond to current
treatment.

Safety data were available for 111 patients in the trial. Patients treated
with ibrutinib experienced treatment-emergent adverse events (AEs) that were
consistent with previously reported data. Treatment-emergent AEs were mainly
grade 1 or 2. Treatment-emergent AEs of all grades occurring in 20 percent or
more patients were diarrhea, fatigue, nausea, upper respiratory tract
infection and dyspnea (shortness of breath). Pneumonia was the only grade 3 or
higher treatment-emergent AE occurring in 5 percent or more patients.

"These results are encouraging because they suggest ibrutinib provided a
durable response in the treatment of mantle cell lymphoma in this Phase 2
study," said Bob Duggan, CEO and Chairman of the Board of Directors of
Pharmacyclics. "Pharmacyclics' overall mission is to improve the quality and
duration of life for oncology patients."

Study Details

PCYC-1104-CA is an international, multicenter, open-label, Phase 2,
single-agent study that treated 111 relapsed or refractory patients (63
bortezomib-naive and 48 bortezomib-exposed) with oral ibrutinib 560 mg daily
for continuous dosing until disease progression. The primary endpoint of the
study is ORR. Duration of response and safety evaluation are important
secondary endpoints.

About Mantle Cell Lymphoma

MCL is an aggressive type of B-cell non-Hodgkin lymphoma (NHL) that usually
occurs in middle-aged or older adults. The disease typically begins in the
lymph nodes but can spread to other tissues, such as bone marrow and liver. In
the United States, there are approximately 70,130 new cases of NHL and 4,600
new cases of MCL each year.

About Ibrutinib

Ibrutinib was designed to specifically target and selectively inhibit an
enzyme called Bruton's tyrosine kinase (BTK). BTK is a key mediator of at
least three critical B-cell pro-survival mechanisms occurring in parallel –
regulating B-cell apoptosis, cell adhesion, and lymphocyte migration and
homing. Data are consistent with a mechanistic model whereby ibrutinib blocks
BCR signaling, which drives cells into apoptosis and/or disrupts cell
migration and adherence to tumor-protective microenvironments.

The effectiveness of ibrutinib alone or in combination with other treatments
is being studied in several B-cell malignancies, including chronic lymphocytic
leukemia/small lymphocytic lymphoma, relapsed/refractory mantle cell lymphoma,
diffuse large B-cell lymphoma, follicular lymphoma and multiple myeloma. A
comprehensive late-stage Phase 2 and 3 program is under way.

Conference Call and Webcast Details

Pharmacyclics will be holding a conference call on Wednesday, December 12,
2012 at 8:30 AM ET. To participate in the conference call, please dial
1-877-407-0778 for domestic callers and 1-201-689-8565 for international
callers. To access the live audio broadcast or the subsequent archived
recording, log on to http://ir.pharmacyclics.com/events.cfm. The archived
version of the webcast will be available for 30 days on the Investor Relations
section of the company's website at www.pharmacyclics.com.

About the Pharmacyclics and Janssen Collaboration

Pharmacyclics, Inc.and Janssen Biotech, Inc. entered into a worldwide
collaboration on December 8, 2011, to develop and commercialize ibrutinib.
Following regulatory approval, Pharmacyclics and Janssen will co-commercialize
ibrutinib. Each company will lead development for specific indications as
stipulated in a global development plan.

About Pharmacyclics

Pharmacyclics^® is a clinical-stage biopharmaceutical company focused on
developing and commercializing innovative small-molecule drugs for the
treatment of cancer and immune mediated diseases. Our mission and goal is to
build a viable biopharmaceutical company that designs, develops and
commercializes novel therapies intended to improve quality of life, increase
duration of life and resolve serious unmet medial healthcare needs; and to
identify promising product candidates based on scientific development and
administrational expertise, develop our products in a rapid, cost-efficient
manner and pursue commercialization and/or development partners when and where
appropriate.

Presently, Pharmacyclics has three product candidates in clinical development
and several preclinical molecules in lead optimization. We are committed to
high standards of ethics, scientific rigor, and operational efficiency as we
move each of these programs to viable commercialization.

The Company is headquartered in Sunnyvale, California and is listed on NASDAQ
under the symbol PCYC. To learn more about how Pharmacyclics advances science
to improve human healthcare visit us at http://www.pharmacyclics.com.

NOTE: This announcement may contain forward-looking statements made in
reliance upon the safe harbor provisions of Section 27A of the Securities Act
of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934,
as amended, including statements, among others, relating to our future capital
requirements and the sufficiency of our current assets to meet these
requirements, our future results of operations, our expectations for and
timing of ongoing or future clinical trials and regulatory approvals for any
of our product candidates, and our plans, objectives, expectations and
intentions. Because these statements apply to future events, they are subject
to risks and uncertainties. When used in this announcement, the words
"anticipate", "believe", "estimate", "expect", "expectation", "should",
"would", "project", "plan", "predict", "intend" and similar expressions are
intended to identify such forward-looking statements. These forward-looking
statements are based on information currently available to us and are subject
to a number of risks, uncertainties and other factors that could cause our
actual results, performance or achievements to differ materially from those
projected in, or implied by, these forward-looking statements. Factors that
may cause such a difference include, without limitation, our need for
substantial additional financing and the availability and terms of any such
financing, the safety and/or efficacy results of clinical trials of our
product candidates, our failure to obtain regulatory approvals or comply with
ongoing governmental regulation, our ability to commercialize, manufacture and
achieve market acceptance of any of our product candidates, for which we rely
heavily on collaboration with third parties, and our ability to protect and
enforce our intellectual property rights and to operate without infringing
upon the proprietary rights of third parties. Although we believe that the
expectations reflected in the forward-looking statements are reasonable, we
cannot guarantee future results, performance or achievements and no assurance
can be given that the actual results will be consistent with these
forward-looking statements. For more information about the risks and
uncertainties that may affect our results, please see the Risk Factors section
of our filings with the Securities and Exchange Commission, including our
annual report on Form 10-K and quarterly reports on Form 10-Q. We do not
intend to update any of the forward-looking statements after the date of this
announcement to conform these statements to actual results, to changes in
management's expectations or otherwise, except as may be required by law.

Note: Data in this release correspond to ASH Abstract 904.

SOURCE Pharmacyclics, Inc.

Website: http://www.pharmacyclics.com
Contact: Ramses Erdtmann, Vice President, Investor Relations and Finance,
+1-408-215-3325