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Interim Data for CPI-0610 in MANIFEST Clinical Trial Showed Signals of Clinical Activity in Myelofibrosis Patients

  • CPI-0610 showed signals of clinical activity, both as a monotherapy and in combination with ruxolitinib, in refractory myelofibrosis (MF) patients
  • Patients treated with CPI-0610 exhibited improvement in spleen volume, constitutional symptoms, anemia, bone marrow fibrosis, and transfusion dependence
  • CPI-0610 was generally well-tolerated as a monotherapy and in combination with ruxolitinib
  • Company to host analyst/investor event and webcast June 4, 2019 at 7:00 AM CDT

CAMBRIDGE, Mass., June 03, 2019 (GLOBE NEWSWIRE) -- Constellation Pharmaceuticals, Inc. (CNST), a clinical-stage biopharmaceutical company using its expertise in epigenetics to discover and develop novel therapeutics, today announced the presentation of updated interim data from MANIFEST, the Company’s Phase 2 clinical trial of CPI-0610 in MF. The interim data, which highlight the tolerability and potentially disease-modifying activity of CPI-0610, were presented in a poster at the annual meeting of the American Society for Clinical Oncology (ASCO) in Chicago.

“We are excited by these interim data from the MANIFEST trial, which indicate that CPI-0610 is generally well-tolerated and showed signs that it is an active therapeutic agent for the treatment of myelofibrosis, both as a monotherapy and in combination with a standard-of-care JAK inhibitor,” said Adrian Senderowicz, M.D., Chief Medical Officer at Constellation Pharmaceuticals. “Moreover, as these data highlight improvements across key hallmarks of myelofibrosis, we believe that CPI-0610 has the potential to address a broad range of unmet needs in patients with this difficult-to-treat cancer. We look forward to the continued evaluation of CPI-0610 in this ongoing Phase 2 trial and to providing additional data from MANIFEST later this year.”

The data were gathered from 44 patients enrolled as of April 17, 2019. Twelve patients received 24-week assessments and 16 patients received 12-week assessments. Below is a summary of results from the interim update across primary and secondary endpoints from the trial:

  • 14 of 16 evaluable patients demonstrated spleen volume reductions. Overall, the median best on-trial spleen volume change from baseline was -19.2%. 

  • Of these 16 evaluable patients, 11 were evaluable for improvement in Total Symptom Score (TSS) according to the Myelofibrosis Symptom Assessment Form, Version 4.0. Six of the 11 (55%) evaluable patients achieved greater than 50% TSS improvement from baseline as a best response.

  • All of these 16 patients were evaluable for Patient Global Impression of Change (PGIC). Fifteen of 16 (94%) evaluable patients reported improvements in PGIC, of which 10 reported feeling either “much improved” or “very much improved” and no patients reported feeling worse following treatment.

  • Of 12 evaluable patients who received at least 24 weeks of treatment, three were severely anemic and dependent on red-blood-cell transfusions at baseline. Of these three patients, two converted to transfusion independence. These two patients have remained transfusion independent for more than 69 and 24 weeks, respectively, as of April 17, 2019, and remain on trial.

  • Ten patients were evaluable for bone marrow fibrosis, of which six (60%) experienced improvement in bone marrow morphology of at least one point on a scale of 0-3. Four of these six patients exhibited improvements within six months of starting CPI-0610 therapy.

Based on the interim data, CPI-0610 was generally well-tolerated, both as a monotherapy and in combination with ruxolitinib. Overall, the most commonly reported side effects (≥10%) were diarrhea, vomiting, upper respiratory tract infection, headache, epistaxis, fatigue, dysgeusia, cough and pruritis. Grade 3 or greater treatment-emergent adverse events were only reported in the combination arm, and those reported in more than one patient included thrombocytopenia, anemia, and decreased platelet counts, each of which was reported in two patients. There was one patient death, which the Company assessed as unlikely to have been related to CPI-0610. The combination therapy of CPI-0610 and ruxolitinib showed a non-cumulative, manageable, and mostly reversible asymptomatic thrombocytopenia.

Each of the first four patients enrolled in MANIFEST, of which two received CPI-0610 as a monotherapy and two received CPI-0610 in combination with ruxolitinib, remained on therapy and had been treated for approximately 16 and 20 months, respectively, as of April 17, 2019.

Please see the poster in the Investors & Media section of Constellation’s website for additional details.

As previously announced in November 2018, Constellation expanded the MANIFEST trial to include a third cohort, designed to evaluate CPI-0610 in combination with ruxolitinib as a first-line therapy in JAK-inhibitor-naïve patients with advanced MF. The Company has begun treating patients in this arm of the trial and expects to provide initial results from this cohort, as well as additional data from the ruxolitinib-resistant and -refractory (second-line) cohorts, in the fourth quarter of 2019. 

Investor Event 

Constellation will host an analyst/investor meeting, with an accompanying conference call and webcast, to discuss this interim update in the Jackson Park D room at Hyatt Regency McCormick Place in Chicago at 8:00 AM EDT/7:00 AM CDT on June 4, 2019. The agenda of the meeting will include:

  • An overview of myelofibrosis (MF) and the potential impact of Constellation’s BET inhibitor CPI-0610 in treating MF
  • A review of the interim data from the MANIFEST clinical trial presented in a poster at ASCO on June 3
  • A panel discussion with two key opinion leaders in MF:
    • Dr. Srdan Verstovsek, a medical oncologist at the University of Texas MD Anderson Cancer Center and an investigator in the MANIFEST trial; and
    • Dr. Raajit Rampal, a hematologic oncologist at Memorial Sloan Kettering Cancer Center

The event will be webcast live and can be accessed on the Investor Relations section of Constellation’s website at http://ir.constellationpharma.com/events-and-presentations/events. Participants may also access the event and participate in the live question-and-answer session by dialing (877) 473-2077 (domestic) or (661) 378-9662 (international) and referring to conference ID 1295319.

Medical Presentation at EHA

Dr. Ronald Hoffman of Mt. Sinai Health System, an investigator in the MANIFEST trial, will make an oral presentation on this interim update of MANIFEST at the European Hematology Association (EHA) annual meeting at 12:15 PM CEST/6:15 AM EDT on June 15, 2019. Slides from the presentation will be posted to Constellation’s website.

About MANIFEST

MANIFEST is an open-label Phase 2 clinical trial of CPI-0610 in patients with myelofibrosis (MF), a rare cancer of the bone marrow that disrupts the body’s normal production of blood cells. Constellation is evaluating CPI-0610, either as a monotherapy or in combination with ruxolitinib, in a second-line setting in patients with MF who are refractory to or intolerant of or have relapsed or lost response to ruxolitinib. Patients in the two second-line arms are being stratified based on transfusion-dependent status. The primary endpoint for the cohorts with transfusion-dependent patients is conversion to transfusion independence for 12 consecutive weeks. The primary endpoint for the patients who were not transfusion-dependent at baseline is spleen volume reduction. In addition, the Company added a third arm designed to evaluate treatment with CPI-0610 in combination with ruxolitinib as a first-line therapy in JAK-1/2-inhibitor-naïve MF patients.   

About Constellation Pharmaceuticals

Constellation Pharmaceuticals is a clinical-stage biopharmaceutical company developing novel therapeutics that selectively modulate gene expression to address serious unmet medical needs in patients with cancer. The Company has a deep understanding of how epigenetic and chromatin modifications in cancer cells and in the tumor and immune microenvironment play a fundamental role in driving disease progression and drug resistance. Constellation is driving development of the EZH2 inhibitors CPI-1205 and CPI-0209 for the treatment of metastatic castration-resistant prostate cancer and other cancers as well as the BET inhibitor CPI-0610 for the treatment of myelofibrosis. The Company is also applying its broad research and development capabilities to explore other novel targets that directly and indirectly impact gene expression to fuel a sustainable pipeline of innovative small-molecule product candidates.    

Forward-Looking Statements

This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 that involve substantial risks and uncertainties, including statements regarding the implications of preliminary or interim clinical data, the development status of the Company’s product candidates, and the Company’s plans for future data presentations. All statements, other than statements of historical facts, contained in this press release, including statements regarding the Company’s strategy, future operations, future financial position, prospects, plans and objectives of management, are forward-looking statements. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in, or implied by, such forward-looking statements. These risks and uncertainties include, but are not limited to, risks associated with Constellation’s ability to: obtain and maintain necessary approvals from the FDA and other regulatory authorities; continue to advance its product candidates in clinical trials; whether preliminary or interim data from a clinical trial will be predictive of the final results of the trial; replicate in later clinical trials positive results found in preclinical studies and early-stage clinical trials of CPI-1205, CPI-0610 and its other product candidates; advance the development of its product candidates under the timelines it anticipates, or at all, in current and future clinical trials; obtain, maintain or protect intellectual property rights related to its product candidates; manage expenses; and raise the substantial additional capital needed to achieve its business objectives. For a discussion of other risks and uncertainties, any of which could cause the Company’s actual results to differ from those contained in the forward-looking statements, see the “Risk Factors” section, as well as discussions of potential risks, uncertainties, and other important factors, in the Company’s most recent filings with the Securities and Exchange Commission. In addition, the forward- looking statements included in this press release represent the Company’s views as of the date hereof and should not be relied upon as representing the Company’s views as of any date subsequent to the date hereof. The Company anticipates that subsequent events and developments will cause the Company’s views to change. However, while the Company may elect to update these forward-looking statements at some point in the future, the Company specifically disclaims any obligation to do so. CPI-1205, CPI-0610, CPI-0209, and other product candidates are investigational in nature and have not yet been approved by the FDA or other regulatory authorities.

Contact

Ronald Aldridge
Senior Director, Investor Relations
Constellation Pharmaceuticals
+1 617-714-0539
ron.aldridge@constellationpharma.com

Lauren Arnold
Media Relations
MacDougall Biomedical Communications
+1 781-235-3060
larnold@macbiocom.com