Pharmacyclics to present clinical updates and posters relating to PCI-24781 and PCI-32765

Pharmacyclics, Inc. (Nasdaq: PCYC) today announced that posters related to PCI-24781 and PCI-32765 have been selected for presentation at the 51st Annual Meeting of the American Society of Hematology (ASH), December 5-8, 2009 in New Orleans, LA.

A material clinical update relating to both the PCI-24781 (HDAC Inhibitor) and PCI-32765 (BTK Inhibitor) programs will be presented at 6pm-8pm EST on Sunday, December 6, 2009 and Monday, December 7, 2009, respectively. The Company plans to issue a press release and hold a conference call related to the above items on December 8, 2009.

Poster details are as follows:

Title: Phase I Analysis of the Safety and Pharmacodynamics of the Novel Broad Spectrum Histone Deacetylase Inhibitor (HDACi) PCI-24781 in Relapsed and Refractory Lymphoma

Date / Time: Sunday, December 6, 2009, 6:00PM-8:00PM Location: Hall E (Ernest N. Morial Convention Center) Poster Board II-702 Poster Session: Lymphoma: Therapy with Biologic Agents, excluding Pre-Clinical Models Poster II Primary presenter: Dr. Andrew Evens, Northwestern University

PCI-24781 is a novel oral pan-HDACi with potent preclinical anti-tumor activity in lymphoma cell lines and models and has previously demonstrated safety and clinical benefit in solid cancers. PCI-24781 is a well tolerated pan-HDACi, including complete absence of prolonged QT abnormalities. Preliminary clinical benefit in heavily pre-treated relapsed/refractory lymphoma patients was documented in the phase I portion of this study as described in the published abstract. Twelve patients were evaluable for response. Two confirmed responses have been seen (1 complete remission, 1 partial remission), while six patients had stable disease with the median length of stable disease being 15 weeks. Accrual will continue to the phase II component of the clinical trial. We plan to provide a material update to the ongoing Phase I/II clinical trials in the form of this poster presentation.

Title: A Phase I Dose Escalation Study of the Btk Inhibitor PCI-32765 in Relapsed and Refractory B Cell Non-Hodgkin Lymphoma and Use of a Novel Fluorescent Probe Pharmacodynamic Assay

Date / Time: Monday, December 7, 2009, 6:00 PM-8:00 PM Location: Hall E (Ernest N. Morial Convention Center) Poster Board III-649 Poster Session: Lymphoma: Chemotherapy, excluding Pre-Clinical Models Poster III Primary presenter: Dr. Daniel Pollyea, Stanford University

PCI-32765 is a novel agent which targets Btk and appears to be well tolerated. The unique pharmacodynamic endpoint suggests high levels of Btk inhibition even at the lowest dosing cohort. Two of 7 patients have stable disease (65 days and 135 days), 3 patients are not yet evaluable for response, and 2 have progressed. Dose escalation to subsequent cohorts is ongoing.