Jounce Therapeutics to Present Safety and Preliminary Efficacy Data on JTX-4014 and a Trials in Progress Poster for the Vopratelimab EMERGE Study at the Society for Immunotherapy of Cancer’s (SITC) 34th Annual Meeting

• Recommended Phase 2 dose determined for future JTX-4014 trials
• Introducing the dosing and sequencing strategy for vopratelimab and ipilimumab in ongoing EMERGE Phase 2 trial

CAMBRIDGE, Mass., Nov. 05, 2019 (GLOBE NEWSWIRE) -- Jounce Therapeutics, Inc. (NASDAQ: JNCE), a clinical-stage company focused on the discovery and development of novel cancer immunotherapies and predictive biomarkers, today announced presentations on two ongoing clinical programs, JTX-4014 and vopratelimab, at the Society for Immunotherapy of Cancer’s (SITC) 34^th Annual Meeting, being held November 6-10, 2019 in National Harbor, Maryland.

“Our poster sessions at this year’s SITC conference demonstrate the progress we have made to date on both of our clinical-stage programs, vopratelimab, an ICOS agonist, and JTX-4014, a PD-1 inhibitor. We have previously shown the relationship between the vopratelimab-associated emergence of ICOS hi CD4 T cells and clinical benefit,” said Elizabeth Trehu, M.D., chief medical officer of Jounce Therapeutics. “The EMERGE trial builds on the biology of induction of ICOS hi CD4 T cells by ipilimumab and their expansion and sustained activation by vopratelimab. We will provide the scientific rationale for the unique dosing and sequencing strategy of ipilimumab and vopratelimab in EMERGE, which we believe optimizes ICOS hi CD4 T cell priming and agonist biology. In a separate poster at SITC, the safety and preliminary efficacy data for JTX-4014 being presented supports the use of this PD-1 inhibitor in combination with our other product candidates.”

Poster Presentation Details:

Title: Phase 1 First in Human Study of Programmed Cell Death Receptor-1(PD-1) Inhibitor Monoclonal Antibody (mAb) JTX-4014 in Adult Subjects with Advanced Refractory Solid Tumor Malignancies
Presentation Date and Time: Friday, November 8, 2019, 7:00am – 8:00pm ET
Presenter: Kyriakos P. Papadopoulos, M.D.
Abstract ID: P439

Jounce researchers describe the safety, preliminary efficacy and recommended Phase 2 doses for JTX-4014 including:

• Acceptable safety profile for JTX-4014 based on a 6-cohort dose-escalation trial. There were no deaths or dose limiting toxicities, few Grade 3/4 adverse events and the only related serious adverse event (SAE) was pneumonitis, which occurred after the second dose at 1200 mg Q3W.
• Antitumor activity observed with an overall response rate of 16.7% (3/18), including 1 complete response and 2 partial responses (confirmed) in a difficult to treat population with no therapeutic options.
• The disease control rate was 44.4% (8/18).
• Typical IgG4 profile with linear pharmacokinetics (PK).
• Planned Phase 2 studies utilizing recommended doses of either 500mg Q3W or 1000mg Q6W.

Title: Phase 2 Multicenter Trial of ICOS Agonist Vopratelimab and a CTLA-4 Inhibitor in PD-1/PD-L1 Inhibitor Experienced Adult Subjects with Non-Small Cell Lung Cancer or Urothelial Cancer (EMERGE)
Presentation Date and Time: Saturday, November 9, 2019, 7:00am – 8:30pm ET
Presenter: Russell K. Pachynski, M.D.
Abstract ID: P438

Jounce researchers highlight the scientific rationale for the ongoing Phase 2 EMERGE trial including:

• Based on reverse translational findings from the ICONIC trial, strategies to optimize emergence and expansion of ICOS hi CD4 T cells have become a cornerstone of the vopratelimab development program.
• The sequence of administration of ipilimumab and vopratelimab combination in EMERGE is designed to induce ICOS hi CD4 T cells with ipilimumab followed by their expansion and sustained activation by vopratelimab.
• A pulsed dose and schedule for vopratelimab, designed to optimize agonist antibody activity, is explored. Specifically, the trial evaluates two different vopratelimab dose levels and a new dosing interval.

Both posters will be available on the “Our Pipeline” section of the Jounce Therapeutics website under “Publications” at www.jouncetx.com.

About Vopratelimab
Jounce’s lead product candidate, vopratelimab (formerly JTX-2011), is a clinical-stage monoclonal antibody that binds to and activates ICOS, the Inducible T cell CO Stimulator, a protein on the surface of certain T cells commonly found in many solid tumors. Vopratelimab was previously assessed in the Phase 1/2 ICONIC trial and was found to be safe and well-tolerated, alone and in combination with each of the anti-PD-1 antibodies nivolumab and pembrolizumab, and ipilimumab, an antibody that binds to CTLA-4. In June 2018, Jounce reported Response Evaluation Criteria in Solid Tumors (RECIST) responses and other tumor reductions as determined by investigator assessment that were associated with an ICOS pharmacodynamic biomarker, ICOS hi CD4 T cells. In April 2019, Jounce reported data on patients in the ICONIC trial with the emergence of ICOS hi CD4 T cells who had improved progression free survival and overall survival compared to patients with ICOS lo CD4 T cells; this was based on an analysis of a subgroup of patients with multiple solid tumor types including PD-1 inhibitor naive and PD-1 inhibitor experienced patients. Vopratelimab is currently being assessed in the Phase 2 EMERGE clinical trial in combination with ipilimumab in patients with non-small cell lung cancer or urothelial cancer who have progressed on or after PD-1/PD-L1 inhibitor therapies.

About JTX-4014
JTX-4014 is a well-characterized fully human IgG4 monoclonal antibody designed to block binding to PD-L1 and PD-L2. Jounce is developing JTX-4014 for potential use in combination with its pipeline of future product candidates. Jounce completed enrollment in the Phase 1 clinical trial of JTX-4014 and additional studies with JTX-4014 with our other product candidates are planned.

About Jounce Therapeutics
Jounce Therapeutics, Inc. is a clinical-stage immunotherapy company dedicated to transforming the treatment of cancer by developing therapies that enable the immune system to attack tumors and provide long lasting benefits to patients through a biomarker-driven approach. Through the use of its Translational Science Platform, Jounce first focuses on specific cell types within the human tumor microenvironment to prioritize targets, and then identifies related biomarkers designed to match the right immunotherapy to the right patient. Jounce is developing two clinical-stage programs as well as advancing and building out its broad and wholly-owned discovery pipeline of immuno-oncology targets, including those expressed on T-regulatory cells, macrophages and stromal cells. Jounce’s lead product candidate, vopratelimab, is a monoclonal antibody that binds to and activates ICOS and is currently being assessed in a Phase 2 clinical trial. JTX-4014 is a PD-1 inhibitor intended for use in combination with future pipeline products, and Jounce has completed enrollment in the JTX-4014 Phase 1 clinical trial. In addition, Jounce has exclusively licensed worldwide rights to JTX-8064, a LILRB2 receptor antagonist, to Celgene. For more information, please visit www.jouncetx.com.

Cautionary Note Regarding Forward-Looking Statements
Various statements in this release concerning Jounce’s future expectations, plans and prospects, including without limitation, Jounce’s expectations regarding the timing, progress and results of the EMERGE clinical trial may constitute forward-looking statements for the purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995 and other federal securities laws and are subject to substantial risks, uncertainties and assumptions. You should not place reliance on these forward-looking statements, which often include words such as “will,” “plan,” “potential” or similar terms, variations of such terms or the negative of those terms. Although Jounce believes that the expectations reflected in the forward-looking statements are reasonable, Jounce cannot guarantee such outcomes. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including, without limitation, Jounce’s ability to successfully demonstrate the efficacy and safety of its product candidates; the clinical results for its product candidates, which may not support further development and marketing approval; the potential advantages of Jounce’s product candidates; the development plans of its product candidates and any companion or complementary diagnostics; actions of regulatory agencies, which may affect the initiation, timing and progress of preclinical studies and clinical trials of Jounce’s product candidates; and those risks more fully discussed in the section entitled “Risk Factors” in Jounce’s most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission as well as discussions of potential risks, uncertainties, and other important factors in Jounce’s subsequent filings with the Securities and Exchange Commission. All such statements speak only as of the date made, and Jounce undertakes no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

Investor Contact:
Komal Joshi
Jounce Therapeutics, Inc.
(857) 320-2523
kjoshi@jouncetx.com

Media Contact:
Kathryn Morris
The Yates Network
914-204-6412
kathryn@theyatesnetwork.com