Levena Biopharma, A Sorrento Company, Announces Positive Clinical Data for Its Out-Licensed A166 Product Candidate, A Third-Generation Anti-HER2-ADC, In Treating Heavily Pretreated HER2-Positive Breast Cancer Patients

• A166 is a third-generation antibody drug conjugate (ADC) against HER2-positive breast cancer with Levena Biopharma’s proprietary tubulin inhibitor Duo-5 toxin, cleavable linker and site-specific K-Lock™ conjugation chemistry.
  
• A166 has demonstrated promising antitumor activity with clinically meaningful responses in heavily pretreated subjects with HER2-positive breast cancer. At a dose of 4.8 mg/kg, A166 demonstrated an 73.9% ORR as compared to the published data from Kadcyla^® (Ado-Trastuzumab Emantsine) of 31.3% ORR, and the PFS with A166 was 12.3 months versus 6 months with Kadcyla.

SAN DIEGO, May 03, 2022 (GLOBE NEWSWIRE) -- Sorrento Therapeutics, Inc. (Nasdaq: SRNE, "Sorrento") today announced that its license and development partner, Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. (“Kelun”), presented at this year’s Chinese Society of Clinical Oncology (CSCO) Guideline Conference (April 23-24, 2022) Phase 1 data for its anti-HER2-ADC, A166. To generate this site-specific third generation ADC, Kelun partnered with Levena Biopharma, a Sorrento company, which provided the proprietary ADC technologies for the generation and production of A166, including (1) a proprietary small molecule toxin, Duostatin-5, a tubulin inhibitor, (2) K-Lock, a site-specific conjugation chemistry and (3) an enzymatically cleavable linker. Compared to Kadcyla^®, the first Antibody-Drug Conjugate approved for the treatment of HER2-positive metastatic breast cancer, A166 demonstrated potentially better efficacy, as shown in the overall response rate (ORR) of 73.9% with A166 at 4.8mg/kg versus Kadcyla^®, which had an ORR of 31.3%, as well as the progression-free survival (PFS) of 12.3 months with A166 versus 6 months with Kadcyla^®.

About Sorrento Therapeutics, Inc. 

Sorrento is a clinical and commercial stage biopharmaceutical company developing new therapies to treat cancer, pain (non-opioid treatments), autoimmune disease and COVID-19. Sorrento's multimodal, multipronged approach to fighting cancer is made possible by its extensive immuno-oncology platforms, including key assets such as fully human antibodies (“G-MAB™ library”), immuno-cellular therapies (“DAR-T™”), antibody-drug conjugates (“ADCs”), and oncolytic virus (“Seprehvec™”). Sorrento is also developing potential antiviral therapies and vaccines against coronaviruses, including Abivertinib, COVISHIELD™ and COVI-MSC™; and diagnostic test solutions, including COVIMARK™.

Sorrento's commitment to life-enhancing therapies for patients is also demonstrated by our effort to advance a first-in-class (TRPV1 agonist) non-opioid pain management small molecule, resiniferatoxin (“RTX”), and SP-102 (10 mg, dexamethasone sodium phosphate viscous gel) (SEMDEXA™), a novel, viscous gel formulation of a widely used corticosteroid for epidural injections to treat lumbosacral radicular pain, or sciatica, and to commercialize ZTlido^® (lidocaine topical system) 1.8% for the treatment of post-herpetic neuralgia (PHN). RTX has been cleared for a Phase II trial for intractable pain associated with cancer and a Phase II trial in osteoarthritis patients. Positive final results from the Phase III Pivotal Trial C.L.E.A.R. Program for SEMDEXA™, its novel, non-opioid product for the treatment of lumbosacral radicular pain (sciatica), were announced in March 2022. ZTlido^® was approved by the FDA on February 28, 2018.

For more information visit www.sorrentotherapeutics.com.

Forward-Looking Statements

This press release and any statements made for and during any presentation or meeting contain forward-looking statements related to Sorrento Therapeutics, Inc., under the safe harbor provisions of Section 21E of the Private Securities Litigation Reform Act of 1995 and subject to risks and uncertainties that could cause actual results to differ materially from those projected. Forward-looking statements include statements regarding A166 (Anti-HER@-ADC); the therapeutic and clinical potential of A166, including its antitumor activity; the potential safety and efficacy of A166 and the clinical testing of A166. Risks and uncertainties that could cause our actual results to differ materially and adversely from those expressed in our forward-looking statements, include, but are not limited to: risks related to Sorrento's technologies and prospects, including, but not limited to risks related to clinical development risks for A166, including risks in the progress, timing, cost, and results of clinical trials and product development programs; risk of difficulties or delays in obtaining regulatory approvals; risks that clinical study results may not meet any or all endpoints of a clinical study and that any data generated from such studies may not support a regulatory submission or approval; risks that prior test, study and trial results may not be replicated in future studies and trials; risks of manufacturing and supplying drug product; risks related to leveraging the expertise of its employees, subsidiaries, affiliates and partners to assist Sorrento in the execution of its product candidates’ strategies; risks related to the global impact of COVID-19; and other risks that are described in Sorrento's most recent periodic reports filed with the Securities and Exchange Commission, including Sorrento's Annual Report on Form 10-K for the year ended December 31, 2021 filed with the Securities and Exchange Commission, including the risk factors set forth in those filings. 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.

Media and Investor Relations

Contact: Brian Cooley
Email: mediarelations@sorrentotherapeutics.com

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G-MAB™, DAR-T™, Seprehvec™, SOFUSA™, COVISHIELD™, COVIDROPS™, COVI-MSC™, and COVIMARK™ are trademarks of Sorrento Therapeutics, Inc.

SEMDEXA™ is a trademark of Semnur Pharmaceuticals, Inc.

ZTlido^® is a registered trademark owned by Scilex Pharmaceuticals Inc.

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