She wrote a business plan around the receptors nobody could tame, then spent two decades proving she could.
A receptor is a lock. Helena Mancebo built a company that makes the keys, the locks, and the bench that tests both - on next-day turnaround.
Most biotech founders pivot. Helena Mancebo did the opposite. She picked one family of proteins - G protein-coupled receptors, the cellular antennae that sit in the membrane and decide which signals get inside - and she has been working on them, only them, for more than twenty years.
"I'm very grateful I wrote a business plan around GPCRs," she told Genetic Engineering & Biotechnology News. "It was the most validated class of drug targets 20 years ago, and it is still among the most prolific for drug targets today."
That kind of patience is rare. GPCRs are responsible for a large share of approved medicines, yet they are notoriously difficult to study. They sulk. They behave one way in a textbook and another way in a dish. Mancebo's company, Multispan, exists because she decided that finickiness was not a bug to complain about but a problem to engineer around.
Her favorite description of the work sounds more like a zookeeper than a CEO. "Each assay and each cell line has a different personality," she says, "and different things can make each one respond in a nice or not-so-nice way. We understand that, and we worked out how to achieve consistent performance." Read that twice. The competitive moat is not a single molecule. It is the unglamorous, hard-won knowledge of how to make a living system do the same thing on Tuesday that it did on Monday.
Today Multispan runs out of Hayward, in the East Bay, with a tight team and an outsized catalog: the industry's largest collection of highly characterized human GPCR clones and GPCR-expressing stable cell lines, including a proprietary high-expression series. Over a thousand clonal cell lines. More than sixteen hundred assay tools. A drug-discovery company spends years getting a target to behave; Mancebo sells the shortcut.
Why GPCRs, of all things? Because they are the body's switchboard. These receptors thread through the cell membrane and convert outside signals - a hormone, a neurotransmitter, a drug - into action inside the cell. They sit upstream of an enormous amount of human physiology, which is exactly why so many medicines aim at them. The catch is that a receptor in isolation tells you very little. Its behavior depends on the cell it lives in, the partners it signals through, and a dozen conditions that shift from one run to the next. That is the gap Mancebo decided to make her company's home: not discovering the receptors, but making them dependable enough to test against.
It is a quietly contrarian position. While much of biotech chases the next platform or the next modality, Mancebo planted a flag on the boring, essential middle of the pipeline - the part where a promising idea either survives contact with a real cell or does not. She is selling certainty in a field that runs on doubt.
Each assay and each cell line has a different personality. We worked out how to achieve consistent performance.
Helena Mancebo, Founder & CEO, Multispan
The leap from scientist to founder is wider than it looks. A researcher chases a result. A founder has to make that result repeatable, sellable, and shippable to a stranger who will judge it by whether it works the first time. Mancebo crossed that gap by treating reliability as the product.
Multispan's pitch to drug hunters is blunt: high-quality data, fast, so the discovery process gets more efficient and more sustainable. The company layers custom compound profiling, cell-line generation, antibody development, CRISPR cell engineering, and frozen cell and membrane preps on top of its catalog - plus the part customers quietly value most, a scientist who will sit with them from assay design through implementation.
One customer summed up the experience in a line that doubles as Mancebo's resume: "Very happy working with Helena and her team. Starting from scratch to get a virtual newco up and running." Starting from scratch is the whole job.
The catalog itself tells the story of a company that kept saying yes to harder requests. What started as cell lines grew to include assay kits and membrane preparations, then beta-arrestin sensor technology, CRISPR gene editing, antibody generation, and bespoke profiling against hundreds of druggable receptors and dozens of orphans - the ones nobody has matched to a function yet. Each capability is a small answer to a customer who showed up with a problem the off-the-shelf product could not solve.
For most of its life Multispan was a specialist that customers had to know to find. That changed in November 2023, when Avantor - a life-sciences supplier with a network that reaches into labs all over the world - added Multispan's cell engineering and assay services to its catalog. Overnight, a boutique East Bay operation got a global shelf.
Mancebo framed the deal in the language of reach, not exit. "Our relationship as a supplier to Avantor enables our broad range of proprietary products and custom services to readily reach a vast network of scientists and researchers and help accelerate their drug discovery research." The interesting part is what she did not do: she did not use scale as an excuse to broaden the mission. The company stayed pointed at the same thing it always had been.
That discipline is the through-line. Bigger distribution, more customers, AI partners - none of it pulled her off the original sentence. Develop and run cell assays. Do it consistently. Do it fast. Everything else is in service of that.
"We plan to stay focused on what we're good at, which is developing and running cell assays."
"Working together with scientists who have shared missions strengthens each of those involved."
"I'm very grateful I wrote a business plan around GPCRs. It is still among the most prolific for drug targets today."
There is a version of this story where the founder gets restless, chases the trend of the season, and loses the plot. Mancebo wrote a different one. She found a hard, important problem early, decided the difficulty was the opportunity, and then refused to be bored by it for two decades. The receptors still misbehave. She still makes them behave. The bet she placed in 2004 keeps paying, which is the rarest thing a bet can do.
Collaboration is important. Working together with scientists who have shared missions strengthens each of those involved.
Helena Mancebo