Press Release Details

-Combination of Rebastinib and Paclitaxel Demonstrates Encouraging Anti-tumor Activity and Favorable Tolerability in Patients with Advanced Endometrial Cancer-

WALTHAM, Mass.--(BUSINESS WIRE)--May 29, 2020-- Deciphera Pharmaceuticals, Inc. (NASDAQ:DCPH) today announced the presentation of data from the endometrial cancer cohort of Part 2 of its ongoing Phase 1b/2 clinical trial of rebastinib, the Company’s investigational orally administered, potent and selective inhibitor of the TIE-2 kinase, in combination with paclitaxel. The presentation, titled “An open-label, multicenter, phase 1b/2 study of rebastinib in combination with paclitaxel in a dose expansion cohort to assess safety and preliminary efficacy in patients with advanced or metastatic endometrial cancer” (abstract 6085; poster 256), will be featured during a poster session at the American Society of Clinical Oncology (ASCO) 2020 Virtual Scientific Program.

“We are very encouraged by the preliminary data from the endometrial cancer cohort,” said Matthew L. Sherman, M.D., Executive Vice President and Chief Medical Officer of Deciphera. “Of the 18 patients included in the modified intent-to-treat population, there were seven partial responses observed, four of which were confirmed, and six patients had stable disease, for an objective response rate of 39% and a clinical benefit rate of 72% at eight weeks. These findings continue to support the potential of TIE-2 inhibition with rebastinib in combination with paclitaxel, including in patients with prior exposure to paclitaxel.”

The Phase 1b/2 study of rebastinib in combination with paclitaxel is a two-part, open-label, multicenter study assessing the safety, tolerability, anti-tumor activity and pharmacokinetics of rebastinib in patients with advanced or metastatic solid tumors. Data previously presented from Part 1 of the study demonstrated encouraging preliminary anti-tumor activity, with objective responses seen across a heavily pre-treated patient population, including patients with prior exposure to paclitaxel. As previously announced, both the endometrial and ovarian cancer cohorts in Part 2 of the study advanced into the second stage of the Simon two-stage design based on demonstrating at least five responses in each cohort.

As of a February 22, 2020 data cutoff date, a total of 21 patients initiated treatment with rebastinib in the Part 2 cohort of endometrial cancer patients. Median duration of treatment was 3.7 months. Sixteen patients were treated at a starting dose of 100 mg of rebastinib twice daily (BID) + weekly paclitaxel 80 mg/m² and five patients at a starting dose of 50 mg of rebastinib BID + weekly paclitaxel 80 mg/m². Three of the 21 patients withdrew consent early, resulting in 18 patients in the modified intent-to-treat (mITT) population.

Preliminary results included:

• Encouraging anti-tumor activity of rebastinib in combination with paclitaxel in the heavily pre-treated endometrial cancer patient population.
  • Of the 21 patients treated with the combination, all received one or more prior lines of the combination of paclitaxel/carboplatin, and 20 of 21 received two or more prior anti-cancer regimens.
• Of the 18 patients included in the mITT population, seven partial responses were observed (four confirmed) and six patients had stable disease, for an objective response rate of 39% and a clinical benefit rate of 72% at eight weeks.
• Treatment with rebastinib 50 mg BID in combination with paclitaxel was well-tolerated, with treatment-emergent adverse events consistent with findings from Part 1 of the study and consistent with first-in-human studies of rebastinib, or known to be associated with treatment with paclitaxel.

Enrollment in Stage 2 of the endometrial cohort at the rebastinib 50 mg BID dose is nearly complete and further efficacy and safety evaluation is ongoing.

A copy of the poster presentation is available at https://www.deciphera.com/science/presentation-publications/.

About Rebastinib

Rebastinib is an investigational, orally administered, potent and selective inhibitor of the TIE2 kinase, the receptor for angiopoietins, an important family of vascular growth factors in the tumor microenvironment that also activate pro-tumoral TIE2 expressing macrophages. In a Phase 1 clinical study, biomarker data have demonstrated rebastinib-induced increases in the TIE2 ligand angiopoietin 2, providing evidence of TIE2 inhibition. Rebastinib is currently being evaluated in a Phase 1b/2 clinical study in combination with paclitaxel (NCT03601897) and in a Phase 1b/2 clinical study in combination with carboplatin (NCT03717415).

About Deciphera Pharmaceuticals

Deciphera is a biopharmaceutical company focused on discovering, developing and commercializing important new medicines to improve the lives of people with cancer. We are leveraging our proprietary switch-control kinase inhibitor platform and deep expertise in kinase biology to develop a broad portfolio of innovative medicines. In addition to advancing multiple product candidates from our platform in clinical studies, QINLOCK^TM is Deciphera’s FDA-approved switch-control kinase inhibitor for the treatment of fourth-line gastrointestinal stromal tumor. For more information, please visit the company’s website at www.deciphera.com.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, our expectations regarding the promise and potential benefit of our clinical programs, including, without limitation rebastinib in combination with paclitaxel for the treatment of endometrial cancer. The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks and uncertainties related to the severity and duration of the impact of COVID-19 on our business and operations, including, without limitation, clinical drug supply chain continuity, our ability to successfully demonstrate the efficacy and safety of our product candidates including in later-stage studies, the preclinical and clinical results for our product candidates, which may not support further development of such product candidates, our ability to manage our reliance on sole-source third parties such as our third party drug substance and drug product contract manufacturers, actions of regulatory agencies, the inherent uncertainty in estimates of patient populations and incidence and prevalence estimates, competition from other products, our ability to obtain, maintain and enforce our intellectual property rights, any or all of which may affect the initiation, timing and progress of clinical studies and the timing of and our ability to obtain additional regulatory approvals, and make our investigational drugs available to patients, and other risks identified in our Securities and Exchange Commission (SEC) filings, including our Quarterly Report on Form 10-Q for the quarter ended March 31, 2020, and subsequent filings with the SEC. We caution you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. We disclaim any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements. Any forward-looking statements contained in this press release represent our views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. We explicitly disclaim any obligation to update any forward-looking statements.

Deciphera, Deciphera Pharmaceuticals, and the Deciphera logo are trademarks of Deciphera Pharmaceuticals, LLC.

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Investor Relations:
Jen Robinson
Deciphera Pharmaceuticals, Inc
jrobinson@deciphera.com
781-906-1112

Media:
David Rosen
Argot Partners
David.Rosen@argotpartners.com
212-600-1902

Source: Deciphera Pharmaceuticals, Inc.