Istari Oncology Abstracts to be Presented at the American Association for Cancer Research (AACR) 2021 Annual Meeting Reflect Continued Progress in the Clinical Development of PVSRIPO

• LUMINOS-101 and LUMINOS-103 study designs to be presented
• Expanding clinical trial program designed to further evaluate PVSRIPO platform in recurrent glioblastoma and a range of solid tumors

DURHAM, N.C.–(BUSINESS WIRE)–Istari Oncology, Inc., a clinical-stage biotechnology company developing PVSRIPO, a novel viral immunotherapy that activates innate and adaptive immunity to facilitate a functional antitumor CD8+ T cell response, today announced two upcoming poster presentations at the American Association for Cancer Research (AACR) Annual Meeting. The AACR Annual Meeting will be held virtually April 10-15 and May 17-21, 2021.

The full text of the following abstracts will be posted to the AACR Online Planner at 12:01 a.m. ET on Friday, April 9 at www.aacr.org and the associated presentations will be made on Saturday, April 10 at the times indicated below. E-posters will be available at on the AACR website at that time and on https://istarioncology.com.

Title: LUMINOS-101: Phase 2 study of PVSRIPO with pembrolizumab in recurrent glioblastoma

Abstract #: CT240
Presenter: Andrea True Kelly, Ph.D.

Session Title/Category: PO.CT08.02 – Phase II Clinical Trials in Progress

Date/time: April 10, 2021, 8:30 a.m. – 11:59 p.m. EDT

ClinicalTrials.gov Identifier: NCT04479241

Title: LUMINOS-103: A basket trial evaluating the safety and efficacy of PVSRIPO in patients with advanced solid tumors

Abstract #: CT242
Presenter: Shannon R. Morris, M.D.

Session Title/Category: PO.CT08.02 – Phase II Clinical Trials in Progress

Date/time: April 10, 2021, 8:30 a.m. – 11:59 p.m. EDT

ClinicalTrials.gov Identifier: NCT04690699

For more information about Istari Oncology and their ongoing clinical trials and research in PVSRIPO, visit www.istarioncology.com.

About PVSRIPO

PVSRIPO is an investigational immunotherapy based on the live attenuated Sabin type 1 poliovirus vaccine that has been genetically modified for safety. PVSRIPO has a distinct target (the poliovirus receptor, CD155), which is expressed on virtually all solid tumors and antigen-presenting cells. Via CD155, PVSRIPO targets tumors with two primary mechanisms: 1) direct damage to and killing of cancerous cells; and 2) engaging innate and adaptive antitumor immune responses via nonlethal infection of antigen presenting cells in the tumor, which stimulates a specific signaling pathway resulting in a sustained, robust type-I/III interferon-dominant response, with minimal release of unwanted cytokines. Its effects are potentiated by prior vaccination against poliovirus. PVSRIPO has been granted Breakthrough Therapy Designation and Orphan Status by the FDA in recurrent glioblastoma. PVSRIPO has also been granted Orphan Status by the FDA for advanced melanoma.

About Istari Oncology

Istari Oncology, Inc., headquartered in Research Triangle Park, North Carolina, is a privately held clinical-stage biotechnology company focused on novel immuno-oncology and immunotherapy platforms for the treatment of glioblastoma and a wide variety of tumors. The company was founded by Darell Bigner, MD, PhD and Matthias Gromeier, MD, of Duke University Medical Center in 2016. Istari licensed a broad range of patents and patent applications from Duke University and has access to additional intellectual property to continue clinical and commercial development of these technologies. The company’s primary platform currently in clinical development is PVSRIPO. For more information, please visit www.istarioncology.com.

Contacts

Istari Oncology Medical Affairs Contact:

Email: [email protected]

Investor Contact:

Stern Investor Relations

Christina Tartaglia

Email: [email protected]

Media Contact:

FleishmanHillard

Leigh Fountain

Email: [email protected]