Atreca and Xencor to Develop T Cell Engaging Bispecific Antibody Directed Against Novel Solid Tumor Target

SAN CARLOS, Calif., and MONROVIA, Calif., Feb. 06, 2023 (GLOBE NEWSWIRE) — Atreca, Inc. (Atreca) (NASDAQ: BCEL), a clinical-stage biotechnology company focused on developing novel therapeutics generated through a unique discovery platform based on interrogation of the active human immune response, and Xencor, Inc. (NASDAQ: XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies and cytokines for the treatment of cancer and autoimmune diseases, today announced, as part of their existing strategic collaboration, they have mutually selected the first program combining an Atreca-discovered antibody with Xencor’s XmAb^® bispecific Fc domain and a cytotoxic T-cell binding domain (CD3).

Under the terms of their 2020 collaboration, Atreca generates novel, tumor-binding antibodies from the immune responses of cancer patients and identifies the antibodies’ targets. Xencor then engineers Atreca’s antibodies into T-cell engaging bispecific antibodies that bind to and activate the CD3 co-receptor on T cells, and characterizes these novel XmAb bispecific antibodies to identify candidates for further development. The program announced today is the first of up to two joint programs that can be mutually selected for further development and commercialization, with each partner sharing 50% of costs and profits. Atreca will lead clinical development, regulatory and commercialization activities for this program, and the second potential joint program would be advanced by Xencor. In addition, the agreement allows for each partner to pursue up to two programs arising out of the collaboration independently.

The joint program announced today is based on APN-346958, an Atreca-discovered antibody. APN-346958 targets a novel RNA-binding protein and is tumor-reactive in at least 50% of samples for six tumor types evaluated, including: colorectal, thyroid, head and neck, urothelial, melanoma and brain cancer. In preclinical studies, the XmAb bispecific antibodies engineered against APN-346958’s target have demonstrated potent anti-tumor activity. Atreca and Xencor expect to name a candidate from the program later this year, and Atreca targets an investigational new drug (IND) submission by early 2025.

“The advancement of this program into joint development is a key milestone in our collaboration with Xencor,” said Stephen Gould, Ph.D., Chief Scientific Officer of Atreca. “We continue to believe that our respective approaches have the potential to be highly complementary, given the abundance of novel antibody-target pairs generated by Atreca’s discovery platform and the plug-and-play nature of Xencor’s XmAb bispecific antibody platform. We are excited to continue working with Xencor to advance this program and generate additional programs combining Atreca antibodies and Xencor CD3 bispecific engineering.”

“We are using our modular protein engineering platforms to create a new generation of XmAb bispecific antibodies that can act directly and selectively against solid tumors with cytotoxic T cell engagement,” said John Desjarlais, Ph.D., Senior Vice President and Chief Scientific Officer at Xencor. “Today’s announcement speaks to the productivity of our ongoing collaboration with Atreca, and we look forward to evaluating additional molecules engineered with antibodies presented by Atreca’s unique and differentiated discovery platform.”

About Atreca, Inc.

Atreca is a biopharmaceutical company developing novel antibody-based immunotherapeutics generated by its differentiated discovery platform. Atreca’s platform allows access to an unexplored landscape in oncology through the identification of unique antibody-target pairs generated by the human immune system during an active immune response against tumors. These antibodies provide the basis for first-in-class therapeutic candidates, such as our lead product candidate ATRC-101, our pipeline of lead-stage oncology programs, and MAM01/ATRC-501, a clinical candidate licensed to the Bill & Melinda Gates Medical Research Institute for the prevention of malaria. A Phase 1b study evaluating ATRC-101 in multiple solid tumor cancers is currently enrolling patients. For more information on Atreca, please visit www.atreca.com.

About Xencor, Inc.

Xencor is a clinical-stage biopharmaceutical company developing engineered antibodies and cytokines for the treatment of patients with cancer and autoimmune diseases. More than 20 candidates engineered with Xencor’s XmAb^® technology are in clinical development, and three XmAb medicines are marketed by partners. Xencor’s XmAb engineering technology enables small changes to a protein’s structure that result in new mechanisms of therapeutic action. For more information, please visit www.xencor.com.

Atreca Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. This press release contains forward-looking statements regarding our strategy and future plans, including statements regarding the development of ATRC-101, MAM01/ATRC-501, and our earlier stage programs, including our clinical and regulatory plans and the timing thereof, the strategic collaboration with Xencor to engineer Atreca’s novel, tumor-binding antibodies into T-cell engaging bispecific antibodies that bind to and activate the CD3 co-receptor on T cells, including our share of costs and profits from the collaboration, the potential for our approach to be highly complementary with Xencor’s approach, the development and commercialization of our joint program with Xencor, the potential for two joint programs with Xencor, the plan for us to lead clinical development, regulatory and commercialization activities for the first joint program and Xencor to advance the second potential joint program, our expectation to name a candidate from the first program with Xencor later in 2022 and target IND submission by early 2025, the plan to continue working with Xencor to advance the joint program and generate additional programs combining Atreca antibodies and Xencor CD3 bispecific engineering, and the potential therapeutic benefits and applications of ATRC-101 and other product candidates from our discovery platform based on interrogation of the active human immune response. These forward-looking statements include, but are not limited to, statements about our plans, objectives, representations and contentions and are not historical facts and typically are identified by use of terms such as “believe,” “will,” “continue,” “potential,” “expect,” “advance” and similar words, although some forward-looking statements are expressed differently. Our actual results may differ materially from those indicated in these forward-looking statements due to risks and uncertainties related to the initiation, timing, progress and results of our research and development programs, preclinical studies, clinical trials, regulatory submissions, and other matters that are described in our most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) and available on the SEC’s website at www.sec.gov, including the risk factors set forth therein. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release, and we undertake no obligation to update any forward-looking statement in this press release, except as required by law.

Xencor Forward-Looking Statements

Certain statements contained in this press release may constitute forward-looking statements within the meaning of applicable securities laws. Forward-looking statements include statements that are not purely statements of historical fact, and can generally be identified by the use of words such as “potential,” “can,” “will,” “plan,” “may,” “could,” “would,” “expect,” “anticipate,” “seek,” “look forward,” “believe,” “committed,” “investigational,” and similar terms, or by express or implied discussions relating to statements regarding future development programs, IND submissions, the quotations from Xencor’s senior vice president and chief scientific officer, and other statements that are not purely statements of historical fact. Such statements are made on the basis of the current beliefs, expectations, and assumptions of the management of Xencor and are subject to significant known and unknown risks, uncertainties and other factors that may cause actual results, performance or achievements and the timing of events to be materially different from those implied by such statements, and therefore these statements should not be read as guarantees of future performance or results. Such risks include, without limitation, the risks associated with the process of discovering, developing, manufacturing and commercializing drugs that are safe and effective for use as human therapeutics and other risks, including the ability of publicly disclosed preliminary clinical trial data to support continued clinical development and regulatory approval for specific treatments, in each case as described in Xencor’s public securities filings. For a discussion of these and other factors, please refer to Xencor’s annual report on Form 10-K for the year ended December 31, 2021 as well as Xencor’s subsequent filings with the Securities and Exchange Commission. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. This caution is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, as amended to date. All forward-looking statements are qualified in their entirety by this cautionary statement and Xencor undertakes no obligation to revise or update this press release to reflect events or circumstances after the date hereof, except as required by law.

Contacts

Atreca, Inc.
Herb Cross
Chief Financial Officer
info@atreca.com

Investors:
Alex Gray, 650-779-9251
agray@atreca.com

Media:
Julia Fuller, 858-692-2001
julia@fordhutmanmedia.com

Xencor Investor Contact:
Charles Liles
cliles@xencor.com
626-737-8118

Xencor Media Contact:
Jason I. Spark
Canale Communications
jason@canalecomm.com
619-849-6005