For many, mRNA-based medicines are synonymous with COVID-19 vaccines, but vaccination is just the tip of the iceberg for the technology. Strand Therapeutics is one of the companies looking below the surface, and it’s raised $52 million to get its first mRNA-based immunotherapy into the clinic.
“We will be aggressively expanding our immuno-oncology pipeline. There are a number of different treatments and treatment settings we’re interested in going after with this platform,” said Strand co-founder and CEO Jake Becraft, Ph.D.
The company isn’t divulging targets and cancer types just yet. It plans to start clinical trials for its first program in 2022 and is working on treatments for solid tumors with BeiGene. It is also building a platform to create in vivo cell therapies, where the cells are modified within the patient’s body rather than needing to be extracted, modified and then given back to the patient.
Short for messenger RNA, mRNA is a molecule that cells use to get genes out of the nucleus and into the cytoplasm, where it produces proteins. Vaccines were the first use for mRNA technologies because it was the lowest-hanging fruit, Becraft said. But the limitations of first-generation approaches made them suitable for vaccination.
MRNA is a transient molecule, meaning it only hangs around in cells making proteins for one to two days before it degrades.
“A short duration of expression is perfect for vaccination—you just want a spike in the expression of antigen in the body and you want it to subside so the immune system can form a memory effect,” Becraft said. And mRNA vaccines don’t need specific targets because they’ll still trigger an immune response no matter which cells they wind up in.
To make mRNAs into therapeutics, drug developers need to make them last longer in the body and zero in on specific tissue types. That’s where Strand comes in.
Its platform allows the creation of mRNAs that that replicate themselves, bringing the therapeutic window from a couple of days to three to four weeks.
“It has a gene that can copy mRNA into more mRNA, so for every molecule that gets into a cell, you get a couple hundred thousand molecules after it undergoes that process,” Becraft said.
Strand’s treatments also use a synthetic biology technology developed at MIT called genetically programmed logic circuits.
“What that allows us to do is take an mRNA sequence and design certain sequence that can be recognized by different biomarkers inside the cell. Then, it can make an autonomous decision as to whether the protein encoded by the RNA should be expressed based on what biomarkers are present within the cell,” Becraft said.
Because the mRNA only “switches on” and makes proteins within the target tissue, the drugs can be given systemically. And this opens the door to combining multiple treatments into a single mRNA medicine.
“All sorts of diseases are multifactorial … And within the field of immuno-oncology, multiple targets can be very powerful since tumors are so heterogeneous,” Becraft said. Combining a cytokine-based medicine with an antibody to be expressed in the tumor microenvironment is just one possibility.
“We haven’t disclosed where else we’re looking, but nothing is really off the table, especially with the increased interest in mRNA in some of the major pharmas,” Becraft said.