OncoSec Expands KEYNOTE-890 Trial into First-Line Metastatic Triple Negative Breast Cancer (mTNBC) with TAVO™ and KEYTRUDA® Plus Chemotherapy

- Tumor Shrinkage and Related Clinical Responses Observed in KEYNOTE-890 in Heavily Pretreated mTNBC Patients Supports Moving to a First-Line Treatment

PENNINGTON, N.J. and SAN DIEGO, June 9, 2020 /PRNewswire/ -- OncoSec Medical Incorporated (NASDAQ:ONCS) (the "Company" or "OncoSec"), a company developing late-stage intratumoral cancer immunotherapies, today announced that, based upon tumor regression and associated clinical responses observed in the heavily pretreated Cohort 1 of the KEYNOTE-890 study, the Company plans to expand into earlier first-line treatment to investigate the combination of OncoSec's lead product candidate TAVO™ (plasmid-based interleukin-12 or pIL-12) and Merck's KEYTRUDA® (pembrolizumab) plus chemotherapy in patients with inoperable locally advanced or metastatic triple negative breast cancer (mTNBC).  Cohort 2 will be added as a second arm to the ongoing KEYNOTE-890 study.  

Merck's Phase 3 KEYNOTE-355 trial evaluating KEYTRUDA in combination with chemotherapy in first-line mTNBC recently reported a statistically significant and clinically meaningful improvement in progression free survival (PFS) with the combination of KEYTRUDA plus chemotherapy versus chemotherapy alone for first-line treatment of patients with PD-L1 positive (CPS ≥10) mTNBC.  Safety was consistent with known profiles of each regimen.  These findings, as well as the strong signal, even in patients with PD-L1 negative tumors, and excellent safety profile observed in KEYNOTE-890 Cohort 1, served as the basis for OncoSec's decision to move into first-line mTNBC.

Specifically, Cohort 2 of the KEYNOTE-890 study will evaluate the addition of TAVO in combination with KEYTRUDA and chemotherapy in the first-line setting in approximately 40 patients with mTNBC.  The primary endpoint will be overall responder rate (ORR) by blinded independent central review (BICR) based on RECIST v1.1. Should positive results from the KEYNOTE 890 Cohort 2 be observed, the Company plans to expand it and utilize the results from the expansion to seek accelerated approval. 

In December 2019, OncoSec presented interim data of 28.6% ORR from Cohort 1 at the San Antonio Breast Cancer Symposium.  These data included four confirmed partial responses, as assessed by the investigator, in 14 patients who were refractory to chemotherapy and had progressed after an average of three prior lines of therapy.  Three of the four responding patients' lesions were PD-L1 negative by IHC analysis before treatment (the fourth patient was undetermined).  Importantly, TAVO and pembrolizumab were well tolerated. 

"TAVO and KEYTRUDA have already demonstrated strong clinical data in heavily pretreated metastatic TNBC patients and we, along with our partners at Merck, recognize a compelling opportunity to improve response rates in a much larger overall patient population by moving into first-line metastatic TNBC where there remains a high unmet medical need," said Daniel J. O'Connor, President and Chief Executive Officer at OncoSec. "We are optimistic about the potential for TAVO to improve progression free survival and overall survival for metastatic TNBC patients. We expect to begin enrollment in KEYNOTE-890 Cohort 2 next quarter and, if successful, intend to expand Cohort 2 into a registration directed study."

For more information about the KEYNOTE-890 study, click here.

About Triple Negative Breast Cancer (TNBC)

TNBC is an aggressive type of breast cancer that characteristically has a high recurrence rate within the first five years after diagnosis. While some breast cancers may test positive for estrogen receptor, progesterone receptor, or human epidermal growth factor receptor 2 (HER2), TNBC tests negative for all three.  As a result, TNBC does not respond to therapies targeting these markers, making it more difficult to treat. Approximately 10-20% of patients with breast cancer are diagnosed with TNBC.

About OncoSec Medical Incorporated
OncoSec Medical Incorporated is a late-stage biotechnology company focused on developing cytokine-based intratumoral immunotherapies to stimulate the body's immune system to target and attack cancer.  OncoSec's lead product candidate, TAVO™, enables the intratumoral delivery of DNA-based interleukin-12 or IL-12, a naturally occurring protein with immune-stimulating functions.  The technology, which employs electroporation, is designed to produce a controlled, localized expression of IL-12 in the tumor microenvironment, enabling the immune system to target and attack tumors throughout the body.  OncoSec has built a deep clinical pipeline utilizing TAVO as a potential treatment for multiple cancer indications either as a monotherapy or in combination with leading checkpoint inhibitors.  The company is currently evaluating TAVO in combination with the anti-PD-1 checkpoint inhibitor, KEYTRUDA® (pembrolizumab), in two KEYNOTE clinical trials, including a pivotal trial in patients with anti-PD-1 checkpoint resistant metastatic melanoma and a phase 2 trial in metastatic triple negative breast cancer.  OncoSec is also identifying and developing new DNA-encoded therapeutic candidates and tumor indications for use with its novel Visceral Lesion Applicator designed to target deep internal lesions, such as liver, lung or pancreatic lesions.  For more information, please visit www.oncosec.com.  

TAVO™ is a trademark of OncoSec Medical Incorporated.

KEYTRUDA® is a registered trademark of Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Risk Factors and Forward-Looking Statements

This release, as well as other information provided from time to time by the Company or its employees, may contain forward-looking statements that involve a number of risks and uncertainties that could cause actual results to differ materially from those anticipated in the forward-looking statements. Forward-looking statements provide the Company's current beliefs, expectations and intentions regarding future events and involve risks, uncertainties (some of which are beyond the Company's control) and assumptions. For those statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. You can identify forward-looking statements by the fact that they do not relate strictly to historical or current facts. These statements may include words such as "anticipate," "believe," "could," "estimate," "expect," "intend," "may," "plan," "potential," "should," "will" and "would" and similar expressions (including the negative of these terms).  Although we believe that expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements. The Company intends these forward-looking statements to speak only at the time they are published on or as otherwise specified, and does not undertake to update or revise these statements as more information becomes available, except as required under federal securities laws and the rules and regulations of the Securities Exchange Commission ("SEC"). In particular, you should be aware that the success and timing of our clinical trials, including safety and efficacy of our product candidates, patient accrual, unexpected or expected safety events, the impact of COVID-19 on the supply of our candidates or the initiation or completion of clinical trials and the usability of data generated from our trials may differ and may not meet our estimated timelines. Please refer to the risk factors and other cautionary statements provided in the Company's Annual Report on Form 10-K for the fiscal year ended July 31, 2019 and subsequent periodic and current reports filed with the SEC (each of which can be found at the SEC's website www.sec.gov), as well as other factors described from time to time in the Company's filings with the SEC.

Company Contact: 
Gem Hopkins
Head of Corporate Communications
858-210-7334
ghopkins@oncosec.com 

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