(State or other jurisdiction

of Incorporation)

(IRS Employer

Identification Number)

500 Totten Pond Road

Waltham, MA

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 203.425)

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Exhibit No.

Description                                     

Exhibit No.

Description                                     

DCC-2618

At the American Society of Clinical Oncology (ASCO) Annual Meeting in June 2018, Deciphera presented updated data from its ongoing Phase 1 clinical trial of DCC-2618 in patients with gastrointestinal stromal tumors (GIST). Highlights from the presentation included:

Initial objective response rates (ORR) and disease control rates (DCR) in second-and third-line GIST patients treated with DCC-2618 at ³100mg daily exceeded previously published results of registrational trials for currently approved therapies, sunitinib in second-line patients and regorafenib in third-line patients.

Mutational profiling data across second-, third- and fourth-line GIST patients demonstrated the breadth of KIT mutations in GIST at baseline and the ability of DCC-2618 to reduce KIT mutant allele frequency.

Deciphera previously announced that following discussions with regulatory authorities in the United States and in Europe, it has designed the INTRIGUE trial as a randomized, multicenter, open-label, Phase 3 trial evaluating DCC-2618 vs. sunitinib in second-line GIST patients. The Company plans to initiate this trial later this year.

Deciphera completed enrollment in the three GIST cohorts in the expansion stage of the ongoing Phase 1 study, totaling 130 patients with second- through fourth-line plus GIST. In addition, enrollment is ongoing in the Company’s Phase 3 INVICTUS study in fourth-line and fourth-line plus GIST.

Deciphera will present an update on the GIST patients in the ongoing Phase 1 study as a Proffered Paper (oral) presentation at the ESMO 2018 Congress. The presentation titled “Initial Results of Phase 1 Study of DCC-2618, a Broad-spectrum KIT and PDGFRa Inhibitor, in Patients (pts) with Gastrointestinal Stromal Tumor (GIST) by Number of Prior Regimens” will be presented on October 19, 2018 in Munich.

In April 2018, the Company reported preclinical data at the Annual Meeting of the American Association for Cancer Research (AACR) demonstrating that compared to the in vitro profiles of the FDA-approved kinase inhibitors imatinib, sunitinib, regorafenib, and midostaurin, and the investigational agent avapritinib (BLU-285), DCC-2618 demonstrated the broadest profile of inhibition of primary and secondary KIT mutations and primary PDGFRα mutations.

The Company also reported updated clinical data at the 2018 AACR Annual Meeting demonstrating the safety and tolerability profile of DCC-2618 in 100 GIST patients treated at the recommended Phase 2 dose of 150 mg QD, which supports the selection of this dose for the ongoing pivotal, randomized Phase 3 INVICTUS study.

Rebastinib

Deciphera expects to initiate a company-sponsored open-label, multicenter Phase 1b study of rebastinib in combination with paclitaxel to assess safety, tolerability and pharmacokinetics in patients with locally advanced or metastatic solid tumors later this year.

DCC-3014

Deciphera continues to enroll patients in the Phase 1 dose escalation study of DCC-3014, a selective CSF1R immunokinase inhibitor, and expects to provide an update from this study later this year.

In June 2018, Deciphera announced the closing of an underwritten public offering of 4,945,000 shares at a public offering price of $40.00 per share, which included the exercise in full by the underwriters of their option to purchase up to 645,000 additional shares of common stock. Total net proceeds to Deciphera were approximately $185.3 million, after deducting underwriting discounts and commissions and other offering expenses.

In May 2018, the Company announced the appointment of Stephen B. Ruddy, Ph.D. as Chief Technical Officer. Dr. Ruddy brings to Deciphera more than 25 years of global pharmaceutical management and leadership experience in small-molecule and biologics development and manufacturing. He will be responsible for establishing and leading a world-class manufacturing and supply chain organization.

In May 2018, the Company also announced the appointment of Steven L. Hoerter, Chief Commercial Officer at Agios Pharmaceuticals, Inc., to its Board of Directors. Mr. Hoerter has more than 25 years of global pharmaceutical and biotechnology experience, having held senior positions at leading oncology companies. He will serve as an independent director and a member of the Nominating and Corporate Governance Committee.

Cash Position: As of June 30, 2018, cash and cash equivalents were $346.5 million compared to cash and cash equivalents of $196.8 million as of December 31, 2017. This increase was primarily related to proceeds obtained through the Company’s recent underwritten public offering offset by cash used in operating activities.

R&D Expenses: Research and development expenses for the second quarter of 2018 were $18.0 million compared to $8.4 million for the same period in 2017. The increase was primarily due to an increase in spending on the DCC-2618 program of $5.5 million as a result of clinical trial costs related to the pivotal Phase 3 INVICTUS study that began enrollment in January 2018 and the ongoing Phase 1 trial. Clinical costs also increased as a result of start-up activities related to the pivotal Phase 3 INTRIGUE study in second-line GIST, which is expected to be initiated in the second half of 2018. Manufacturing costs increased for DCC-2618 as a result of new process development to support anticipated greater drug requirements for commercialization as well as the manufacture of registration lots required to support the submission of a new drug application. Expenses related to our rebastinib program increased approximately $0.6 million primarily as a result of start-up activities related to our planned clinical trials. In addition, personnel-related, facility-related and other costs increased an aggregate of $3.6 million as the result of an increase in costs associated with an increase in headcount and incurred in connection with our early-stage drug discovery programs. Personnel costs for each of the second quarters of 2018 and 2017 included non-cash share-based compensation expense of $1.0 million and $0.2 million, respectively.

G&A Expenses: General and administrative expenses for the second quarter of 2018 were $4.5 million, compared to $2.2 million for the same period in 2017. The increase was primarily due to an increase in non-cash share-based compensation expense related to additional employee stock options and a higher value of our common stock and to an increase in legal and professional fees as a result of various advisory fees related to ongoing operations as a public company as well as costs incurred for pre-commercialization activities. Non-cash share-based compensation was $1.2 million and $0.4 million for each of the second quarters of 2018 and 2017, respectively.

Net Loss: For the second quarter of 2018, Deciphera reported a net loss of $21.7 million, or $0.65 per share, compared with a net loss of $10.6 million, or $0.91 per share for the same period in 2017.

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In May 2018, we entered into a lease for office space in Waltham, MA. We are not the legal owners of the leased space, however, we are deemed to be the owner during the construction phase beacuse of certain provisions within the lease. As a result, we recorded a $17.0 million build-to-suit asset in property and equipment and a corresponding build-to-suit facility lease financing obligation.

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