The Next Generation of Peptide Medicine
Why We Invested in Lion Bio
Mark Jacobstein · November 5, 2026
With apologies to The Graduate, I’ve got one word for you, kid: peptides.
Today we’re announcing that South Park Commons led the $6M pre-seed round in Lion Bio, a consumer biotech company building the next generation of peptide medicines. Congrats to founding CEO Robin Guo, scientific co-founder Kam Leong, and the whole team.
When people talk about the magic of modern medicine, they talk about the molecule: the drug that hits the target, melts the tumor, or fixes a broken pathway. Almost nobody talks about how the drug gets where it’s going. Does the stomach destroy it first? Can it reach the brain? Does it last six hours or a week? Does it make you nauseous?
But many of the most important developments in the history of therapeutics have hinged on novel delivery mechanisms, from transdermal patches to Bob Langer’s polymer systems for timed release of large molecules.
Hitting the right target isn’t enough. GLP-1s prove it. The molecule boosts insulin and quiets appetite, and it’s reshaping medicine, but it also comes as a weekly injection, and many patients quit because of the nausea.
Drug delivery is the problem Robin founded Lion Bio to solve.
Robin is a unique founder. He’s a biomedical engineer from Columbia, but he’s also great with GTM and fundraising (as evidenced by his time at Riot Games and standing up a16z’s Speedrun). Lion Bio requires Kam’s frontier material science, but also preclinical translation, clinical development, manufacturing, and consumer marketing.
Lion Bio’s origin story is compelling: Robin learned about Kam’s foundational biomaterials work through his father Ed (himself a biology professor at Columbia), and immediately appreciated the implications of the platform for numerous neurological diseases.
What Kam had created was a novel nanoparticle wrapper that lets large peptides cross the lining of the nose. The early animal data are compelling. Without the nanoparticles the drugs simply don’t work.
Is it critical to deliver a drug through your nose? Yes, as it turns out. No needle, for one thing. Taking a weekly shot sucks. And who loves disposing of their sharps?
The (daily, or even real-time) ease of intranasal delivery means doses can be (much) lower, and the nose is a side door to the brain, connecting directly along the olfactory and trigeminal nerves, partly bypassing the blood-brain barrier.
These advantages should reduce side effects, a real problem for many GLP-1s.
More importantly, the connection to the brain may be critical for many neuroactive peptides. There is, for example, early but promising data regarding the ability of peptides to act on addictions of all sorts, from nicotine to alcohol and beyond. Every week seems to bring more exciting news regarding both the ability of peptides to regulate pathways that matter, and faster paths to market for new peptide formulations.
All of which is why we’re excited to partner with Lion Bio to build the nanoparticle platform for neuropeptide delivery.
At SPC, we love working with founders like Robin and Kam who take on massive technical risk to solve fundamental human problems.
