BIOATLA ANNOUNCES PRICING OF INITIAL PUBLIC OFFERING

December 15, 2020

December 15, 2020

SAN DIEGO, Calif., December 15, 2020 -- BioAtla, Inc. (Nasdaq: BCAB), a clinical-stage biopharmaceutical company developing a novel class of highly specific and selective antibody-based therapeutics for the treatment of solid tumor cancer, today announced the pricing of its initial public offering of 10,500,000 shares of common stock at a public offering price of $18.00 per share. All of the shares of common stock are being offered by BioAtla. The shares of common stock are expected to begin trading on the Nasdaq Global Market on December 16, 2020 under the ticker symbol "BCAB." The gross proceeds of the offering, before deducting underwriting discounts and commissions and other offering expenses payable by BioAtla, are expected to be approximately $189.0 million. The offering is expected to close on December 18, 2020, subject to the satisfaction of customary closing conditions. In addition, BioAtla has granted the underwriters a 30-day option to purchase up to an additional 1,575,000 shares of common stock at the initial public offering price, less underwriting discounts and commissions.

J.P. Morgan, Jefferies and Credit Suisse are acting as joint book-running managers for the offering.

Registration statements relating to these securities became effective on December 15, 2020. The offering is being made only by means of a prospectus, copies of which may be obtained, when available, from: J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, New York 11717, by telephone at (866) 803-9204, or by email at prospectus-eq_fi@jpmchase.com; Jefferies LLC, Attention: Equity Syndicate Prospectus Department, 520 Madison Avenue, 2nd Floor, New York, New York 10022, by telephone at (877) 821-7388, or by email at Prospectus_Department@Jefferies.com; or Credit Suisse Securities (USA) LLC, Attention: Prospectus Department, 6933 Louis Stephens Drive, Morrisville, North Carolina 27560, by telephone at (800) 221-1037, or by e-mail at usa.prospectus@credit-suisse.com.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About BioAtla

BioAtla is a clinical-stage biopharmaceutical company developing a novel class of highly specific and selective antibody-based therapeutics for the treatment of solid tumor cancer.

Media Contact:

Richard A. Waldron
BioAtla, Inc.

rwaldron@bioatla.com

Investor Contact:

Richard A. Waldron
BioAtla, Inc.

rwaldron@bioatla.com

BioAtla® and Sinobioway Select First Program for Strategic Collaboration in China Market

January 6, 2016

BioAtla© receives $19 million in first program payments plus equity

SAN DIEGO, CA - January 6, 2016 - BioAtla© LLC, a global biotechnology company focused on the development of Conditionally Active Biologic (CAB) antibody therapeutics, today announced that BioAtla© and Beijing Sinobioway Group Company, Limited (Sinobioway) selected their first product programs for development. In May 2015, BioAtla© and Sinobioway entered into a strategic collaboration for the development and commercialization of select CAB antibodies and other CAB-based therapeutics in China, Hong Kong, Macau and Taiwan (the Territory). Related to and as a result of this agreement, BioAtla© received a previously reported $30 million equity investment from a China-based investor group. BioAtla© now receives $19 million in program payments plus equity investment from Sinobioway as a result of the selection of the first CAB candidates and achievement of other corporate objectives. Including these funds, BioAtla© will receive a total of more than $70 million in program payments and equity investment from Sinobioway over the course of the next twelve months.

BioAtla© and Sinobioway are working collaboratively to develop several CAB candidates for the Territory. As part of the agreement, Sinobioway has exclusive rights to develop and commercialize selected CAB antibodies in the Territory and BioAtla© retains the rest of world (ROW) rights to these products. Sinobioway will fund the development, manufacturing, clinical trials and commercialization costs in the Territory and is committed to making recurring product development payments to BioAtla© for additional CAB candidates. BioAtla© is further eligible to receive certain milestone payments and double-digit royalties on sales.

This strategic collaboration is the keystone of BioAtla©'s long-term plans to address the growing high demand for innovative therapeutic products in the China pharmaceutical market. BioAtla©'s patent protected Conditionally Active Biologics platform represents a disruptive technology for the development of a powerful new class of immunotherapeutics that are activated in selected microenvironments within the body, such as those indicative of cancerous tumors. CABs can be generated in several different formats including naked monoclonal antibodies (mAbs), antibody drug conjugates, immune checkpoint inhibitors, bispecific antibodies, and chimeric antigen receptor (CAR) T cells.

"BioAtla©'s strategy is to broadly and rapidly pursue novel therapeutic products based on our patented CAB and other proprietary technologies," said Jay M. Short, Ph.D., president, chief executive officer and chairman of the board of BioAtla©. "China is an immensely important opportunity for CABs and we are excited to be working with Sinobioway with its demonstrated commitment and strong capabilities to execute and to fulfill our mutual goals. Since BioAtla©'s founding in 2007, we have utilized our San Diego and Beijing development and operations capabilities to successfully develop dozens of protein products under contract and shared development. We will continue to build upon our drug development experience to pursue the great prospects of the CAB platform for our collaboration with Sinobioway, as well as for our collaboration with Pfizer that we announced last month on December 8, and for our portfolio of proprietary CAB products."

"Conditionally Active Biologics is an innovative and breakthrough technology to develop the new class of immuno-oncology therapeutics," said Dr. Pan Aihua, chairman of Sinobioway. "The CAB technology and its prospects will be important elements in Sinobioway's mission to advance science and industrial development, and improve health in China through creating and delivering safer and more effective medicines to patients."

About Conditionally Active Biologics (CABs)

Conditionally Active Biologic proteins are generated using BioAtla©'s proprietary protein evolution and expression technologies. These proteins can be mAbs, enzymes and other proteins designed with functions dependent on changes in microphysiological conditions (e.g., pH level, oxidation, temperature, pressure, presence of certain ions, hydrophobicity and combinations thereof).

Studies have shown that cancerous tumors create highly specific conditions at their site that are not present in normal tissue. These cancerous microenvironments are primarily a result of the well understood unique glycolytic metabolism associated with cancer cells, referred to as the Warburg Effect, which was first described in the early 1900's and is the basis of the widely-used PET scan cancer detection method today. CAB-designed mAbs can be programmed to deliver their therapeutic payload and/or recruit the immune response in specific and selected locations and conditions within the body. CABs increase safety because the drug's activation depends on its presence in a particular cellular microenvironment thereby preferentially binding to its intended target protein in the area of disease. In addition, the activation is reversible and can repeatedly switch ‘on and off' should the CAB product move from a diseased to a normal cellular microenvironment and vice versa thereby further reducing chances the CAB would bind to the same protein located in healthy tissue or in other parts of the body and cause undesirable toxicity.

CABs allow for higher dosing, the development of effective, non-immunogenic drugs, and the use of targets that are validated for cancer cells but traditionally considered too prevalent among normal cells to be used safely in current drug therapies. This opens a potentially rich range of targets for CABs that cannot be addressed using existing technologies. CABs may also be employed as diagnostic tools to reveal and pinpoint conditions indicative of cancerous activity.

About Beijing Sinobioway Group Company, Limited

Sinobioway was founded in 1992 and is one of the three main industrial groups affiliated with Peking University. Sinobioway is a leader in establishing a bioeconomy system in China and developing that country's bio-industry. It invests in biomedicine, bioagriculture, bioenergy, bioenvironment, bioservices, biomanufacturing and biointelligence. Biologic therapeutics is a particular focus of Sinobioway in its plans to develop and commercialize new medicines. Sinobioway is constructing a large biologics production facility, with a long-term capability goal of 100 production lines, in the planned 20 billion RMB bio-economic zone under construction in Hefei.