Sorrento Reports Promising Results With mRNA Vaccine For COVID-19 Delivered With The MuVaxx Lymphatic Drug Delivery Device

Sorrento’s mRNA vaccine (“STI-mRNA”) delivered with the MuVaxx™ Lymphatic Drug Delivery Device (“MuVaxx”), at 1/10th of the dose vs an LNP-mRNA reference standard1 (“LNP-mRNA”) delivered intramuscularly (“IM”), demonstrated in preclinical studies a 400% improvement in cellular immunity and similar humoral immunity (anti-receptor binding domain (RBD) IgG and anti-S1 IgG antibodies). SAN DIEGO, Aug. 26, 2021 (GLOBE NEWSWIRE) — Sorrento Therapeutics, Inc. (Nasdaq: SRNE, “Sorrento”), a clinical and commercial stage biopharmaceutical company developing new therapies to treat cancer, pain (non-opioid treatments), autoimmune disease and COVID-19, today announced promising preclinical results for its mRNA vaccine against SARS-CoV-2. STI-mRNA is comprised of proprietary designer Spike-encoding mRNAs to elicit cellular and humoral immunity against the early WA-1 virus as well as the predominant and emerging variants of concern (VOCs), including Alpha, Beta, Gamma, Delta, and Lambda. Currently marketed vaccines have demonstrated reduced efficacy against the major SARS-CoV-2 emerging VOCs2, with declining efficacy over time3. Novel approaches are needed that improve durability for both humoral and cellular immunity against current and emerging variants. The MuVaxx lymphatic drug delivery device is designed to deliver vaccine into the epidermis to potentially enable access and increased exposure to dendritic (antigen-presenting) cells in the skin and in lymph nodes at lower doses than with intramuscular administration. Initial preclinical results are summarized below, and complete results are accessible at: https://www.biorxiv.org/content/10.1101/2021.08.25.457699v1 Intramuscular (IM) STI-mRNA (10µg) compared to the IM LNP-mRNA (10µg) showed a dramatic 400% improvement in cellular immunity as measured by cytokine production of spike specific CD8 T cells.This elevated level of cellular immune response was also observed at 1/10th of the STI-mRNA dose using the MuVaxx lymphatic drug delivery device.STI-mRNA (1/10th dose delivered with MuVaxx) also demonstrated similar humoral immunity (anti-RBD IgG and anti-S1 IgG antibodies) as compared to the IM LNP-mRNA reference (10µg) and IM STI-mRNA (10µg). These preclinical findings are significant as cellular immunity is critical for impeding virus replication and conferring long-term protection. Additionally, current approved LNP-mRNA vaccines have been shown to potentially have dose-dependent side effects4. The STI-mRNA and MuVaxx combination appear to elicit a similar humoral response and an elevated cellular response against the SARS-CoV-2 virus, at a fraction of the current vaccine doses. These initial preclinical results provide the basis for Sorrento to move forward aggressively with IND-enabling studies with our MultiValent STI-mRNA vaccine candidate. References 1. LNP mRNA Reference Standard – This reference standard used is a similar construct as to LNP mRNAs used in current EUA authorized vaccines. 2. J. L. Bernal, N. Andrews, et.al., “Effectiveness of COVID-19 Vaccines against the B.1.617.2 (Delta) Variant”; The New England Journal of Medicine; 2021; 385:585-594. 3. S. J. Thomas, E. D. Moreira, et.al., “Six Month Safety and Efficacy of BNT1626b2 mRNA COVID-19 Vaccine; medRxiv Preprint; 101/2021.07.28.21261159 4. Jackson, et. al., “An mRNA Vaccine against SARS-CoV-2”, The New England Journal of Medicine, 2020;383:1920-31 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, COVIGUARD™, COVI-AMG™, COVISHIELD™, COVI-MSC™ and COVIDROPS™; and diagnostic test solutions, including COVITRACK™, COVISTIX™ and COVITRACE™. 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. RTX has completed a Phase IB trial for intractable pain associated with cancer and a Phase 1B trial in osteoarthritis patients. SEMDEXA is in a pivotal Phase 3 trial for the treatment of lumbosacral radicular pain, or sciatica. 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 the expectations for Sorrento’s technologies and product candidates, including, but, not limited to, Sorrento’s STI-mRNA vaccine program, including its STI-mRNA vaccine candidate delivered with the MuVaxx Lymphatic Drug Delivery Device; the potential effectiveness of STI-mRNA administered intramuscularly with the MuVaxx device against the WA-1 virus and variants of concern, including the Alpha, Beta, Gamma, Delta and Lambda variants; the potential that administering STI-mRNA intramuscularly with the MuVaxx device at a reduced dosage, including 1/10th of the standard dose, will result in an improvement in cellular immunity and/or similar humoral immunity compared to the current LNP-mRNA reference standard (10µg); the potential for STI-mRNA administered intramuscularly with the MuVaxx device to result in reduced dose-dependent side effects compared to current approved LNP-mRNA vaccines; Sorrento’s plans and expected timing for completing IND-enabling studies for STI-mRNA; and Sorrento’s potential position in the antiviral industry. 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 conducting preclinical and IND-enabling studies, and seeking IND regulatory approval for STI-mRNA; conducting and receiving results of clinical trials for STI-mRNA; the clinical and commercial success of STI-mRNA against preventing COVID-19; clinical development risks, 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 therapeutic antibody product candidate 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, 2020, and subsequent Quarterly Reports on Form 10-Q 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 ContactAlexis Nahama, DVM (SVP Corporate Development)Email: [email protected] Sorrento® and the Sorrento logo are registered trademarks of Sorrento Therapeutics, Inc. G-MAB™, DAR-T™, SOFUSA™, MuVAXX™, COVIGUARD™, COVI-AMG™, COVISHIELD™, COVIDROPS™, COVI-MSC™, COVITRACK™, COVITRACE™ and COVISTIX™ are trademarks of Sorrento Therapeutics, Inc. SEMDEXA™ is a trademark of Semnur Pharmaceuticals, Inc. ZTlido® is a registered trademark owned by Scilex Pharmaceuticals Inc. All other trademarks are the property of their respective owners. ©2021 Sorrento Therapeutics, Inc. All Rights Reserved.