Leap Therapeutics Presents Biomarker Data from Clinical Study of DKN-01 in Combination with Paclitaxel in Esophageal Cancer

• Durable responses observed in patients with Wnt-pathway genetic mutations
  

CAMBRIDGE, Mass., Jan. 19, 2017 -- Leap Therapeutics, Inc. reported updated clinical and biomarker data from an ongoing study of DKN-01, a monoclonal antibody against the Dickkopf-1 (DKK1) protein, in patients with cancer of the esophagus and gastroesophageal junction. Data from the trial identified genetic mutations that may be responsive to DKN-01 therapy, as well as decreased circulating immunosuppressive and angiogenic markers that are consistent with the anticipated mechanism of action of DKK1 inhibition. The data were presented today by John Strickler, M.D., of the Duke University Medical Center and an investigator on the trial, at the American Society for Clinical Oncology Gastrointestinal Cancers Symposium.  

Four of 19 patients evaluated with genetic testing were found to have activating/stabilizing mutations of beta-catenin, which is a molecule in the Wnt signaling pathway implicated in oncogenesis, metastasis, and immune suppression. Of these 4 patients, 2 achieved partial responses (PR) per RECIST v.1.1 and 1 had prolonged stable disease. One patient has an ongoing response exceeding 20 months, of which the past 9 months have been on DKN-01 monotherapy with continued improvements in the disease.

“Wnt/beta-catenin signaling is often dysregulated in cancer, leading to increased proliferation, metastasis, and immune suppression. These early clinical results are encouraging and give important insights into patient selection in these highly aggressive cancers,” commented Dr. Strickler.

In the study to date, Leap has enrolled 44 patients with advanced esophageal and gastroesophageal junction cancers who had received between 1 and 7 prior lines of therapy.  10 of 41 evaluable patients achieved a PR and 15 patients achieved a best overall response of stable disease, representing a total disease control rate of 61%. Leap is continuing to enroll patients in this study and has opened a new cohort specifically for patients with gastric cancer with known Wnt pathway mutations.

About DKN-01

DKN-01 is a humanized monoclonal antibody that binds to and blocks the action of the Dickkopf-1 (DKK1) protein, a modulator of Wnt/Beta-catenin signaling. DKK1 expression has been associated with poor prognosis in multiple cancers.  Recent literature suggests DKK1 has an important role in tumor cell signaling and in mediating an immuno-suppressive tumor microenvironment. DKN-01 is being studied in clinical trials in patients with esophageal, gastric, and biliary tract cancers. DKN-01 has demonstrated single agent activity in non-small cell lung cancer patients.

About Leap Therapeutics

Leap Therapeutics’ most advanced clinical candidate, DKN-01, is a humanized monoclonal antibody targeting the Dickkopf-1 (DKK1) protein. DKN-01 is in clinical trials in patients with gastroesophageal cancer in combination with paclitaxel and in patients with biliary tract cancers in combination with gemcitabine and cisplatin. Leap’s second clinical candidate, TRX518, is a novel, humanized GITR agonist monoclonal antibody designed to enhance the immune system’s anti-tumor response. Leap has signed a Merger Agreement with Macrocure Ltd (Nasdaq:MCUR) that is expected to result in Leap becoming a public company that will trade on The Nasdaq Global Market under the symbol “LPTX.” For more information about Leap Therapeutics, visit http://www.leaptx.com or our public filings with the SEC that are available via EDGAR at http://www.sec.gov.

FORWARD LOOKING STATEMENTS

Some of the statements in this release are forward looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties.  These statements relate to the potential merger with Macrocure Ltd, future events of Leap’s development of DKN-01, TRX518, and other programs, future expectations, plans and prospects.  Although Leap believes that the expectations reflected in such forward-looking statements are reasonable as of the date made, expectations may prove to have been materially different from the results expressed or implied by such forward-looking statements.  Leap has attempted to identify forward looking statements by terminology including "believes," "estimates," "anticipates," "expects," "plans," "projects," "intends," "potential," "may," "could," "might," "will," "should," "approximately" or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements.  These statements are only predictions and involve known and unknown risks, uncertainties, and other factors.  Any forward looking statements contained in this release speak only as of its date.  We undertake no obligation to update any forward-looking statements contained in this release to reflect events or circumstances occurring after its date or to reflect the occurrence of unanticipated events.

CONTACT
Douglas E. Onsi
Chief Financial Officer
Leap Therapeutics, Inc.
[email protected]
617-714-0360

Joe Rayne 
MacDougall Biomedical Communications
[email protected]
781-235-3060