Portola Pharmaceuticals Presents New Interim Data from Ongoing Phase 2a Study of its Oral SYK/JAK Inhibitor Cerdulatinib in Heavily Pre-Treated T-Cell Malignancies

SOUTH SAN FRANCISCO, Calif., Dec. 8, 2019 /PRNewswire/ -- Portola Pharmaceuticals, Inc.^® PTLA today announced new interim results from the Company's ongoing Phase 2a study of cerdulatinib, an investigational, oral SYK/JAK inhibitor, in patients with specific subtypes of T-cell Non-Hodgkin Lymphoma, including relapsed/refractory peripheral T-cell lymphoma (PTCL); angioimmunoblastic T-cell lymphoma (AITL), a subset of PTCL; and cutaneous T-cell lymphoma (CTCL). The data will be presented today during an oral session at the 61^st American Society of Hematology (ASH) Annual Meeting in Orlando (December 7-10).

As of the November 12, 2019 cut-off date, 64 PTCL patients and 40 CTCL patients treated with cerdulatinib as a single agent were evaluable for response. The overall response rate (ORR) was 34% in the PTCL cohort and 43% in the CTCL cohort. Among the subset of patients in the PTCL cohort with AITL, the ORR was 52% and the complete response rate (CR) was 37%.

"Relapsed or refractory PTCL and CTCL remain challenging diseases to treat given their heterogenous nature and lack of uniformly effective therapies," said Steven M. Horwitz, M.D., an oncologist at Memorial Sloan Kettering Cancer Center. "I am encouraged to see these updated results, which underscore the potential of cerdulatinib to address a range of rare, aggressive sub-types of T-cell malignancies as well as benefits in terms of quality-of-life measures, such as pruritus, which can be a significant burden for patients with cutaneous lymphomas." 

Among the 64 patients in the PTCL cohort, 14 patients (22%) achieved a CR and eight patients (12%) achieved a partial response (PR). In the subgroup of 27 patients with AITL, 10 patients (37%) achieved a CR, and four patients (15%) achieved a PR. The median duration of response is eight months for all PTCL patients and is greater than nine months in AITL patients. Follow-up is ongoing.

Among the 40 patients in the CTCL cohort, three patients (8%) achieved a CR and 14 patients (35%) achieved a PR. Importantly, rapid improvements in pruritus, or severe itching – a common and often serious condition associated with CTCL – have been observed, as measured by the Likert scale.

Cerdulatinib demonstrated good tolerability in both PTCL and CTCL. The most common Grade 3 or greater adverse events across the PTCL and CTCL cohorts with a frequency > 5% were lipase increase (25%), amylase increase (19%), neutropenia (12%), anemia (10%), diarrhea (8%), sepsis/bacteremia (6%), and febrile neutropenia (4%). The lipase and amylase changes were generally asymptomatic and not associated with pancreatitis.  

"We are encouraged by the continued safety and efficacy profile of cerdulatinib in patients with PTCL and CTCL, and the potential it has to meet medical needs through dual SYK and JAK pathway inhibition as the most advanced therapy of its kind currently in development for oncology," said Jeff Myers, Portola's interim chief medical officer. "We look forward to the planned initiation of our registrational trial in patients with PTCL in the coming months, and to gathering additional evidence on the clinical activity of cerdulatinib."

ASH Oral Session Details – Sunday, December 8, 2019, at 12:45 p.m. EST

About the Phase 2a Study
The Phase 2a, open-label study was designed to assess the safety and efficacy of cerdulatinib in patients with specific subtypes of relapsed/refractory T-cell Non-Hodgkin Lymphoma – including PTCL and CTCL, B-cell Non-Hodgkin lymphoma alone or in combination with rituximab, chronic lymphocytic leukemia, and small lymphocytic lymphoma.

About Cerdulatinib

Cerdulatinib is an investigational oral, dual spleen tyrosine kinase (SYK) and janus kinase (JAK) inhibitor that uniquely inhibits two key cell signaling pathways implicated in certain hematologic malignancies and autoimmune diseases. There is a strong rationale for inhibiting both SYK (B-cell receptor pathway) and JAK (cytokine receptors) in B-cell malignancies where both targets have been shown to promote cancer cell growth and survival.

The U.S. Food and Drug Administration granted cerdulatinib Orphan Drug Designation for the treatment of PTCL in September 2018.

About Portola Pharmaceuticals, Inc.
Portola Pharmaceuticals is a global, commercial-stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutics that could significantly advance the fields of thrombosis and other hematologic conditions. The Company's first two commercialized products are Andexxa^® [coagulation factor Xa (recombinant), inactivated-zhzo], marketed in Europe as Ondexxya^® (andexanet alfa), and Bevyxxa^® (betrixaban). The company also is advancing cerdulatinib, a SYK/JAK inhibitor being developed for the treatment of hematologic cancers. Founded in 2003 in South San Francisco, California, Portola has operations in the United States and Europe. 

Forward-Looking Statements
Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements regarding the anticipated development plan for cerdulatinib. Risks that contribute to the uncertain nature of the forward-looking statements include: the risk of unfavorable results from additional clinical trials involving cerdulatinib; our ability to successfully execute on our development strategy; the risk of unfavorable regulatory developments; our expectation that we will incur losses for the foreseeable future and will need additional funds to finance our operations; the effects of competition; the accuracy of our estimates regarding expenses and capital requirements; our ability to successfully market Andexxa; our ability to obtain and maintain intellectual property protection for our product candidates; our ability to retain key scientific or management personnel; and general market conditions. These and other risks and uncertainties are described more fully in our most recent filings with the Securities and Exchange Commission, including our most recent quarterly report on Form 10-Q. All forward-looking statements contained in this press release speak only as of the date on which they were made. We undertake no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.

SOURCE Portola Pharmaceuticals, Inc.®