La Jolla agreement provides for $43.0 million in upfront cash plus potential future cash payments of up to $16.0 million pursuant to contingent value rights

Combined company will offer two innovative therapies to treat patients suffering from life-threatening diseases

SAN DIEGO, CA & WATERTOWN, MA, USA I June 24, 2020 I La Jolla Pharmaceutical Company, which is dedicated to the development and commercialization of innovative therapies that improve outcomes in patients suffering from life-threatening diseases, and Tetraphase Pharmaceuticals, Inc. (Nasdaq: TTPH), a biopharmaceutical company focused on commercializing its novel tetracycline XERAVA™ to treat serious and life-threatening infections, today announced that they have entered into a definitive merger agreement. Under the terms of the definitive merger agreement, La Jolla would acquire Tetraphase, through a tender offer, for $43.0 million in upfront cash plus potential future cash payments of up to $16.0 million pursuant to contingent value rights (CVRs). The Board of Directors of Tetraphase unanimously recommends that stockholders tender their shares in the La Jolla tender offer once it is commenced.

Under the terms of the definitive merger agreement, the upfront cash consideration in the transaction will be as follows: (i) $2.00 per share of Tetraphase common stock (including common stock underlying restricted stock units, performance-based stock units and pre-funded warrants); (ii) $2.68 per share of Tetraphase common stock underlying the common stock warrants issued by Tetraphase in November 2019; and (iii) $2.69 per share of Tetraphase common stock underlying the common stock warrants issued by Tetraphase in January 2020. Tetraphase equity holders would also be entitled to receive, for each share of Tetraphase common stock, one non-tradeable CVR. The holders of the CVRs would be entitled to receive payments of up to an additional $16.0 million in the aggregate upon the achievement of certain net sales of XERAVA™ in the United States (U.S.) as follows: (i) $2.5 million if 2021 XERAVA U.S. net sales are ≥ $20 million; (ii) $4.5 million if XERAVA U.S. net sales are ≥ $35 million during any calendar year ending on or prior to December 31, 2024; and (iii) $9.0 million if XERAVA U.S. net sales are ≥ $55 million during any calendar year ending on or prior to December 31, 2024.

“Combining with La Jolla, which markets GIAPREZA, the first new treatment for patients suffering from septic or other distributive shock in more than a decade, should help accelerate XERAVA’s availability to patients in need,” said Larry Edwards, President and Chief Executive Officer of Tetraphase. “We are excited to have the opportunity to combine with a company that has a strategic vision similar to our own.”

“We commend Tetraphase on its successful commercial launch of XERAVA, an important new treatment for patients suffering from serious infections,” said Kevin Tang, Chairman of La Jolla. “By increasing our presence in the hospital with a second innovative therapy, we look forward to better serving the needs of patients suffering from life-threatening diseases.”

Under the terms of the definitive merger agreement, the tender offer will commence within three business days. Any shares not tendered in the tender offer will be acquired in a second-step merger at the same cash price as paid in the tender offer. Closing of the transaction is subject to specified closing conditions, including that a majority of Tetraphase’s shares of common stock (treating the shares underlying Tetraphase’s RSUs and PRSUs as outstanding) are validly tendered and not validly withdrawn. Upon the closing of the transactions, Tetraphase will become a wholly owned subsidiary of La Jolla, and shares of Tetraphase’s common stock will no longer be listed on any public market. Subject to certain limited exceptions, the CVRs will be non-transferable.

The transaction was unanimously approved by the Tetraphase board of directors and is expected to close in the third quarter of 2020. Certain Tetraphase stockholders and warrant holders, including Armistice Capital, LLC, holding in the aggregate approximately 20% of Tetraphase’s outstanding voting power, have signed support agreements or exchange agreements under which such equity holders agreed, among other things, to tender their shares in the tender offer and to the treatment of the warrants described above. Additionally, La Jolla owns shares in Tetraphase that represent approximately 15% of Tetraphase’s outstanding voting power.

On June 24, 2020, Tetraphase terminated its previously announced merger agreement with Melinta Therapeutics, Inc., dated as of June 4, 2020, in order to enter into the definitive merger agreement with La Jolla. In connection with the termination of the definitive merger agreement with Melinta, Tetraphase paid Melinta a termination fee in the amount of $1,150,000.

Janney Montgomery Scott is acting as financial advisor to Tetraphase and has rendered a fairness opinion to Tetraphase’s board of directors in connection with the transaction. Wilmer Cutler Pickering Hale and Dorr LLP is acting as legal advisor to Tetraphase in connection with the transaction.

About GIAPREZA

In December 2017, GIAPREZA™ (angiotensin II) was approved by the U.S. Food and Drug Administration (FDA) as a vasoconstrictor indicated to increase blood pressure in adults with septic or other distributive shock. In August 2019, GIAPREZA was approved by the European Commission (EC) for the treatment of refractory hypotension in adults with septic or other distributive shock who remain hypotensive despite adequate volume restitution and application of catecholamines and other available vasopressor therapies. GIAPREZA mimics the body’s endogenous angiotensin II peptide, which is central to the renin-angiotensin-aldosterone system, which in turn regulates blood pressure. Prescribing information for GIAPREZA is available at www.giapreza.com. The European Summary of Product Characteristics is available on the EMA website: www.ema.europa.eu/en/medicines/human/EPAR/giapreza. GIAPREZA is marketed in the U.S. by La Jolla Pharmaceutical Company on behalf of La Jolla Pharma, LLC, its wholly owned subsidiary.

About XERAVA

XERAVA (eravacycline for injection) is a novel fluorocycline of the tetracycline class antibacterials indicated for the treatment of complicated intra-abdominal infections (cIAI) in patients 18 years of age and older. XERAVA was investigated for the treatment of cIAI as part of Tetraphase’s IGNITE (Investigating Gram-Negative Infections Treated with Eravacycline) Phase 3 program. In the first pivotal Phase 3 trial in patients with cIAI, twice-daily intravenous (IV) XERAVA met the primary endpoint by demonstrating statistical non-inferiority of clinical response compared to ertapenem and was well-tolerated. In the second Phase 3 clinical trial in patients with cIAI, twice-daily IV XERAVA met the primary endpoint by demonstrating statistical non-inferiority of clinical response compared to meropenem and was well-tolerated. In both trials, XERAVA achieved high cure rates in patients with Gram-negative pathogens, including resistant isolates.

Please see full prescribing information for XERAVA.

About La Jolla Pharmaceutical Company

La Jolla Pharmaceutical Company is dedicated to the development and commercialization of innovative therapies that improve outcomes in patients suffering from life-threatening diseases. In December 2017, GIAPREZA™ (angiotensin II) was approved by the U.S. Food and Drug Administration (FDA) as a vasoconstrictor indicated to increase blood pressure in adults with septic or other distributive shock. In August 2019, GIAPREZA was approved by the European Commission (EC) for the treatment of refractory hypotension in adults with septic or other distributive shock who remain hypotensive despite adequate volume restitution and application of catecholamines and other available vasopressor therapies. For more information, please visit www.ljpc.com.

About Tetraphase Pharmaceuticals, Inc.

Tetraphase Pharmaceuticals, Inc., is a biopharmaceutical company using its proprietary chemistry technology to create novel tetracyclines for serious and life-threatening conditions, including infections caused by many of the multidrug-resistant bacteria highlighted as urgent public health threats by the World Health Organization and the Centers for Disease Control and Prevention. Tetraphase has created more than 3,000 novel tetracycline compounds using its proprietary technology platform. Tetraphase’s lead product, XERAVA™, is approved for the treatment of complicated intra-abdominal infections by the U.S. Food and Drug Administration and the European Commission. Tetraphase’s pipeline also includes antibiotics TP-271 and TP-6076, which are Phase 2 ready, and TP‑2846, which is in preclinical testing for acute myeloid leukemia. Tetraphase intends to out license its pipeline candidates. Please visit www.tphase.com for more company information.

SOURCE: La Jolla Pharmaceutical Co