SAN DIEGO, CA, USA I December 20, 2021 I Sorrento Therapeutics, Inc. (Nasdaq: SRNE, “Sorrento”) today announced that the U.S. Food and Drug Administration (FDA) has granted clearance to proceed with a Phase 1b clinical trial using STI-1386, Seprehvec™, entitled “Dose Escalation Study of the Safety and Preliminary Efficacy of STI-1386 Oncolytic Virus in Patients with Relapsed or Refractory Solid Tumors.”

STI-1386, or Seprehvec, is a 2nd generation oncolytic herpes simplex virus type 1 (oHSV) developed following the acquisition of Virttu Biologics by Sorrento in 2017 and produced in Sorrento’s GMP virus therapeutics manufacturing facility. The Seprehvec backbone is deleted of both RL1 gene copies, eliminating expression of the neurovirulence factor ICP34.5 and restricting virus proliferation to cells which are rapidly dividing, i.e., tumor cells. Seprehvec additionally expresses transgenes encoding an anti-PD-1 scFv-Fc isolated from the Sorrento G-MAB antibody library, a TGF beta receptor 2 decoy, and interleukin-12.

These transgene-encoded proteins secreted by Seprehvec-infected tumor cells are designed to act in a coordinated fashion to enhance immune-mediated tumor destruction by i) inhibiting the PD-1/PDL-1 immune checkpoint pathway, ii) diminishing the immunosuppressive effects of TGF beta in the tumor microenvironment, and iii) providing a localized IL-12 signal to activate and attract T cells and NK cells to the tumor.

“Seprehvec allows for locoregional immune stimulation at the tumor site while potentially minimizing the undesired effects that may accompany systemic immune stimulation. Our initial focus is to develop Seprehvec for treatment of sarcomas, pancreatic carcinomas, and hepatic metastases, with expansion to additional solid tumor indications in the future,” said Mike Royal, MD, JD, MBA, Chief Medical Officer of Sorrento.

Robert Allen, PhD, Senior Vice President of Antiviral and Oncolytic Immunotherapy Development, commented, “Seprehvec provides a unique means of simultaneously bringing multiple tumor-killing and tumor-suppressing elements to bear on solid tumors, which are notoriously hard to eradicate. Using this same approach, we are currently progressing additional oHSV candidates that mediate recruitment and activation of anti-tumor responses from specific subsets of immune cells. The virologists, cancer immunologists, and manufacturing scientists at Sorrento continue to leverage the breadth and quality of the G-MAB library, delivering best-in-class next-generation oHSVs, antibodies, and cellular immunotherapies to patients.”

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, COVI-AMG™, COVISHIELD™, COVI-MSC™ and COVIDROPS™; and diagnostic test solutions, including COVITRACK™ and COVISTIX™.

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.

SOURCE: Sorrento Therapeutics