SRI’s Targeted Antigen Loaded Liposomes (TALL) — a treatment that expands the benefits of immunotherapy such as check-point inhibitors — has been granted Orphan Drug Designation (ODD) for pancreatic ductal adenocarcinoma (PDAC) by the U.S. Federal Drug Administration (FDA).
As a result, SRI’s future strategic partners can gain tax credits for qualified clinical trials and potentially receive market exclusivity for a period of seven years after the drug’s approval, among other benefits.
“FDA’s orphan drug designation brings worthy attention to the demonstrated impact of SRI’s TALL biotherapeutic for pancreatic cancer,” said Kathlynn Brown, president of SRI’s biosciences division. “This milestone fuels SRI’s deep commitment to pioneering health and precision medicine solutions that bring hope to patients and their families.”
Treating resistant cancer
Pancreatic cancer is difficult to detect in early stages and has the highest mortality rate of all major cancers with only a 3% relative-survival-rate at 5 years for the advanced form. Pancreatic tumors are highly resistant to chemotherapy and radiation and there are limited treatment options. SRI’s TALL is a novel immunotherapy with the potential to overcome these and other challenges and greatly extend the benefits to more patients.
“SRI is to be congratulated for advancing to this pivotal step,” said Dr. Timothy Cote, former head of the FDA ODD Program and current CEO of Only Orphans Cote. “Their science in this field is strong and the FDA has affirmed that they are providing a genuine orphan drug. SRI’s work in the precision medicine domain sets a standard for the industry and offers life-changing solutions for those in need.”
An orphan drug is intended for use in rare diseases. More than 7,000 rare diseases have been identified, and an estimated one in 10 Americans lives with a rare disease; half are children. Still, roughly 95% of these diseases don’t have FDA approved treatments. To encourage organizations to address patient unmet needs, the federal government passed the Orphan Drug Act in 1983. As a key function of the Act, organizations can apply to be ODD approved for specific treatments.
“This greatly streamlines the go-to-market process toward final FDA clinical drug approval,” said Brown. “We are looking forward to working with our strategic partners to offer the ability to take advantage of the tremendous cost savings and other benefits that come with this designation, including tax credits for clinical trials and a faster go-to-market timeline.”
Tricking cancer cells to attract therapy
TALL is designed to trick the immune system into recognizing tumor cells as pathogen-infected cells. Essentially, TALL makes cancer cells look like they have the measles, exploiting the biological phenomenon known as recall immunity to encourage the human immune system to seek out and kill an invader it already knows how to fight.
SRI created TALL using the company’s novel FOX Three platform, which was developed to solve another critical drug development challenge: biotherapeutic compounds that have traditionally been difficult to deliver to the inside of cells and therefore make the targets inside those cells undruggable. FOX Three employs proprietary processes to identify unique peptide delivery agents (known as Molecular Guidance Systems, or MGS) that home to targeted cell types and deliver a therapeutic payload in a cell-specific fashion.
For application as immunotherapy, a synthetic peptide derived from the measles virus is packed into neutral, stealth particles known as liposomes. Then, a tumor-targeting FOX Three MGS is attached to the surfaces of the liposomes. The MGSs home to tumor cells and, once there, the liposomes are transported into the tumor cells.
The measles-derived peptide is then released inside the diseased cells and eventually presented on their surfaces, flagging them for the immune system. The measles ‘infected’ tumor cells are then targeted and killed by memory T cells, and the patient’s immune system clears the tumor. Data showing TALL given as a co-therapy to check-point inhibitors has demonstrated increased tumor reduction for tumors that have been traditionally resistant to check-point inhibitor therapies. TALL essentially turns a cold tumor to hot and enables drugs to work more effectively.
“The FDA ODD program and its potential brings hope to many cancer patients fighting this horrible disease and we look forward to reaching more patients through the accelerated process.” Brown concluded.
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