New I-Cell™ COVID-19 Cellular Vaccine Program launched by Sorrento Therapeutics

Sorrento Therapeutics has launched its breakthrough I-Cell™ COVID-19 Cellular Vaccine Program and is currently engaged in intensive consultations with the FDA to accelerate development, with the intention of starting human clinical trials by the summer of 2020.

The STI-6991 I-CellTM COVID-19 cellular vaccine

Sorrento Therapeutics, Inc. (Nasdaq: SRNE) confirmed on Wednesday that it has been developing a new COVID-19 cell decoy vaccine (STI-6991) and is in talks with the FDA’s Center for Biologics Evaluation and Review under IND#019724 about the necessary IND-enabling trials, CMC (chemistry, manufacturing and controls), clinical procedure and future rapid approval endpoints. After obtaining guidance from the FDA, Sorrento plans to send a full package for IND filing that would allow human clinical trials to begin as early as possible.

Sorrento scientists have conceptualised and developed the decoy cell technique (I-Cell™, which means immune-training cells), exploiting the skills gained in the battle against cancer.

I- Cell™ vaccine to trigger both T cell and B cell immunity to SARS-CoV-2

The California based biotech plans to use a well-known replicating cell line (human erythroleukemia, K562) to integrate the spike protein of SARS-CoV-2 or its S1 domain onto the cell membrane simulating that the viral protein is introduced on a decoy cell surface to evoke T cell and B cell immunity to COVID-19.

The chosen cell line was used safely in cancer vaccination programmes and is well defined (clinical trials utilising the colony-stimulating factor K562 expressing granulocyte-macrophage were used as a tumour vaccine). The decoy cell “looks like” the virus to the immune system of a healthy human, as the viral protein is released as a surface marker. The cells may be delivered as a vaccination by intramuscular injection following irradiation to avoid cell replication.

The receiver can generate a defensive immune response and produce corresponding neutralising antibodies against the SARS-CoV-2 virus, in the presence of this training cell “look alike.” If the vaccinated subject is subsequently exposed to the SARS-CoV-2 coronavirus, its T-cell protection and neutralising antibodies are expected to inhibit the viral spike protein from binding to the usual human cell surface of the ACE2 (angiotensin converting enzyme 2), thus possibly attenuating or stopping the SARS-CoV-2 infection that triggers COVID-19.

The COVID-19 cellular vaccination strategy

A short communication explaining this vaccination approach was accepted for publication by Medicine in Drug Discovery (an Elsevier peer-reviewed open access journal.

Per the publication, “the overall strategy to utilize a viral antigen-expressing, non-replicating cellular system as both a carrier, and as an immunogenic antigen-presenting platform is novel. The view is that this platform will be recognized by the immune system, and a neutralizing antibody response will ensue. The most important aspect of the platform is that it should allow for dendritic cells to recruit T lymphocytes and induce Th1 cell polarization that if feasible will also induce a cytotoxic T cell response and thus clearance of SARS-CoV-2 virus. The strategy should be safe as they are using K562 cell line that is HLA negative. The platform appears to be readily scalable and would appear to provide uniform cell product. One key aspect is that will the vaccine prevent engraftment and proliferation after host implantation; the answer here appears to be yes as the cells will be irradiated post-expansion in order to abolish their replication ability and thus no in vivo cell growth. In sum an intriguing platform is put forth and if viable as it appears to be it could make an impact on the treatment of COVID-19.”

Sorrento is currently working to prove the capacity of I-Cells inside an animal model to build defensive T-cell and B-cell immunity.

In support of the Phase 1 clinical study and accelerated deadlines, Sorrento has established a major infectious disease contract research company.

Sorrento’s cGMP cell therapy facilities in San Diego

At its state-of-the-art cGMP cell therapy facilities in San Diego, Sorrento has started process development, validation and scaling-up of production studies in anticipation of registrational clinical studies and marketing. Sorrento anticipates that its current cGMP cell therapy facilities should be able to manufacture sufficient quantities of drug substance to satisfy the requirement of the final drug product (the COVID-19 Cellular Vaccine) for millions of monthly doses if approved.

Human trials as early as mid-2020

The company expects all IND requirements will be fulfilled in the coming months. Depending on the support from the government and the response from the FDA, Sorrento believes it may be able to initiate human vaccination tests as early as mid-2020.

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