CTI BioPharma Establishes Accelerated Approval Pathway for Pacritinib in Treating Myelofibrosis Patients With Severe Thrombocytopenia

SEATTLE, Feb. 3, 2020 /PRNewswire/ -- CTI BioPharma Corp. (Nasdaq: CTIC) today announced that following a meeting with the U.S. Food and Drug Administration ("FDA" or "the Agency"), CTI has reached agreement on an accelerated approval pathway for pacritinib for the treatment of myelofibrosis patients with severe thrombocytopenia (platelet counts <50,000/µL). CTI will be amending the PACIFICA pivotal Phase 3 trial protocol to allow for the primary analysis of SVR rates on the first 168 patients, with an end-of-study analysis of TSS and OS following the full enrollment of 348 patients. If the primary endpoint of SVR is met following the planned review of data from the first 168 patients, CTI intends to submit a New Drug Application (NDA) under the FDA's subpart H regulations, subject to review of all available efficacy and safety data. Conversion to a regular approval of pacritinib would be anticipated following the successful end-of-study assessment of the secondary efficacy endpoints, and the completion of post-marketing requirements.

"Since the initiation of the PACIFICA trial in September 2019, we have been working diligently with the FDA to identify an expedited approval pathway for pacritinib for the treatment of myelofibrosis patients with severe thrombocytopenia," said Adam R. Craig, M.D., Ph.D., President and Chief Executive Officer of CTI Biopharma. "Severely thrombocytopenic myelofibrosis patients (platelet counts <50,000/µL) have reduced survival and very limited therapeutic options. Pacritinib has now demonstrated clinical benefit in this population in three clinical trials, including two prior randomized Phase 3 studies, so we believe that pacritinib has the potential to change the treatment paradigm in this area of serious unmet medical need."

Based on the new trial design, CTI expects to report primary SVR data by the end of 2021, with a potential NDA filing in early 2022 if the SVR data is positive. Final study efficacy data is expected in 2023.

Concurrent with this press release, CTI is announcing a $60 million rights offering. For further details, see the concurrent press release relating to the rights offering.

About Myelofibrosis and Severe Thrombocytopenia
Myelofibrosis is a type of bone marrow cancer that results in formation of fibrous scar tissue and can lead to severe anemia, weakness, fatigue and an enlarged spleen and liver. Patients with severe thrombocytopenia are estimated to make up more than one-third of patients treated for myelofibrosis, or approximately 17,000 people. Severe thrombocytopenia, defined as blood platelet counts of less than 50,000 per microliter, has been shown to result in overall survival rates of just 15 months. Thrombocytopenia in patients with myelofibrosis is associated with the underlying disease but has also been shown to correlate with treatment with ruxolitinib, which can lead to dose reductions, and as a result, may potentially reduce clinical benefit. Survival in patients who have discontinued ruxolitinib therapy is further compromised, with an average overall survival of seven to 14 months. There are currently no approved therapies available to treat myelofibrosis patients with severe thrombocytopenia or patients who have failed ruxolitinib treatment, thereby making this a significant unmet medical need.

About Pacritinib
Pacritinib is an investigational oral kinase inhibitor with specificity for JAK2, FLT3, IRAK1 and CSF1R. The JAK family of enzymes is a central component in signal transduction pathways, which are critical to normal blood cell growth and development, as well as inflammatory cytokine expression and immune responses. Mutations in these kinases have been shown to be directly related to the development of a variety of blood-related cancers, including myeloproliferative neoplasms, leukemia and lymphoma. In addition to myelofibrosis, the kinase profile of pacritinib suggests its potential therapeutic utility in conditions such as acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), chronic myelomonocytic leukemia (CMML), and chronic lymphocytic leukemia (CLL), due to its inhibition of c-fms, IRAK1, JAK2 and FLT3.

About CTI BioPharma Corp.
CTI BioPharma Corp. is a biopharmaceutical company focused on the acquisition, development and commercialization of novel targeted therapies for blood-related cancers that offer a unique benefit to patients and their healthcare providers. In particular, we are focused on evaluating pacritinib for the treatment of adult patients with myelofibrosis. CTI BioPharma is headquartered in Seattle, Washington.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. These forward-looking statements include statements regarding our expectations regarding: the anticipated trial design of the PACIFICA Phase 3 trial, including changes to the protocol as discussed in this press release; the anticipated enrollment of the PACIFICA Phase 3 trial; the effectiveness of, and potential changes to, the PACIFICA Phase 3 trial design; the timing of, and results from, clinical trials and other development activities related to pacritinib, including the PACIFICA Phase 3 trial and its related protocol; the potential efficacy, safety profile, future development plans, addressable market, regulatory success and commercial potential of pacritinib; the anticipated timing of regulatory submissions and interactions, including any potential NDA submission; our ability to expedite the regulatory approval process; our ability to successfully develop and achieve milestones in the development of pacritinib; and the anticipated benefits of pacritinib.

Risks Related to Forward-Looking Statements
The forward-looking statements contained in this press release are based on current assumptions that involve risks, uncertainties and other factors that may cause the actual results, events or developments to be materially different from those expressed or implied by such forward-looking statements. These risks and uncertainties, many of which are beyond our control, include, but are not limited to: clinical trials may not demonstrate safety and efficacy of pacritinib; the FDA may determine that the benefit/risk profile of pacritinib at the dose selected for the PACIFICA Phase 3 trial does not support approval based on the results of such trial, previously identified FDA concerns regarding safety and dosing limitations or otherwise; pacritinib may fail in development, may not receive required regulatory approvals, or may be delayed to a point where it is not commercially viable; our assumptions regarding our planned expenditures and sufficiency of our cash to fund operations may be incorrect; we may not achieve additional milestones in our pacritinib development program; the impact of competition; the impact of expanded product development and clinical activities on operating expenses; adverse conditions in the general domestic and global economic markets; as well as the other risks identified in our filings with the Securities and Exchange Commission. These forward-looking statements speak only as of the date hereof and we assume no obligation to update these forward-looking statements, and readers are cautioned not to place undue reliance on such forward-looking statements.

"CTI BioPharma" and the CTI BioPharma logo are registered trademarks or trademarks of CTI BioPharma Corp. in various jurisdictions. All other trademarks belong to their respective owner.

CTI BioPharma Investor Contacts:
Maeve Conneighton/Maghan Meyers

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