The pastry chef who patented an anti-cancer molecule that’s been bought for over $8 billion

Eduard Batlle spent every Christmas of his youth in his parents’ pastry shop, helping to make thousands of Three Kings’ Day cakes. It was the 1980s, and the family confectionery was located in a working-class neighborhood between Barcelona and the city of Hospitalet de Llobregat. “There were tons of drugs; some of my friends ended up badly addicted to heroin. On Saturdays, I would go with my mother to the pastry shop so that she wouldn’t be alone: we were constantly being robbed at knifepoint. It was a pretty rough time,” Batlle recalls.

His life has changed somewhat since then. Inspired by the 1980s television series Cosmos, he studied biology and, a decade ago, he and five colleagues invented a molecule, petosemtamab. In its initial trials, it has shown apparent promise in curing some cases of cancer. The Danish company Genmab has just paid around seven billion euros ($8.2 billion) to acquire this experimental drug, co-designed by the former pastry chef.

“This is Peto,” Batlle proclaims with a smile. He picks up an empty glass vial and holds it in the air, while speaking with this newspaper in his tiny office at the Barcelona-based Institute for Research in Biomedicine. This small vial was used to treat the first person to try the drug, back in May of 2018. The initial results were promising, but the real surprise came six months ago. Petosemtamab – combined with standard immunotherapy – achieved the complete remission of tumors in six people with head and neck cancer. This disease invades the mouth and throat and is associated with tobacco and alcohol use. Of the 43 participants in the trial, 63% had a partial or complete response to the treatment.

Batlle, born in Barcelona 55 years ago, shows EL PAÍS the dramatic photograph of a woman with an enormous tumor in her mouth. Doctors considered her a hopeless case, because neither chemotherapy nor immunotherapy had worked for her. She was given petosemtamab intravenously. “The tumor disappeared,” Batlle recalls. “It’s incredible. All of us who dedicate ourselves to research dream of curing people. For us, this is a dream come true, a very unexpected one,” he exclaims.

Petosemtamab exists because two boys became friends more than half-a-century ago, at a school in the Netherlands. One was Hans Clevers, now a geneticist and Nobel Prize nominee for his work on organoids: miniature versions of human organs, grown in a lab from stem cells. The other was Ton Logtenberg, now a serial entrepreneur in the biotechnology sector. In 2003, Logtenberg founded a company in Utrecht called Merus, to try to create antibodies against cancer: artificial proteins that bind to tumor cells at a specific point and cause their destruction.

Merus’ innovation lies in its technology for producing antibodies that are capable of acting on two sites on the same cancer cell simultaneously, guaranteeing its annihilation.

In 2012, the entrepreneur asked his scientist friend for the name of an internationally-recognized expert on colon cancer, with the goal of trying to cure this specific type of cancer, which kills nearly a million people each year. Clevers suggested a name: Eduard Batlle, a Spanish biologist who, between 2000 and 2004, had worked as a postdoctoral researcher in his laboratory at the Hubrecht Institute in Utrecht. The three of them got to work.

Batlle was already an international authority on colon cancer at that time. While still in his thirties, in Utrecht, he had illuminated the relationship between the stem cells that regenerate the intestine and those that trigger colon cancer. In 2005, he was recruited to help found the Institute for Research in Biomedicine, a center of the University of Barcelona and the regional government of Catalonia in Spain.

So, the Dutch company Merus knew how to produce antibodies with dual action. Hans Clevers was an expert on organoids, those little spheres of living cells derived from patients on which drugs could be tested in the laboratory. And Batlle knew the intricacies of colon cancer. The team set about searching for weaknesses in tumor cells and developing various antibodies. They tested more than 500 for months, until they found one with “spectacular results.” The team initially called it MCLA-158. Later, it was renamed “petosemtamab.” Nowadays, however, everyone calls it “Peto,” as if it were another colleague. Its mechanism of action (MOA) is revolutionary: it’s the first drug candidate targeting cancer stem cells in solid tumors.

Three months ago, the Danish giant Genmab announced its acquisition of the Dutch company Merus for nearly €7 billion ($8.2 billion), with the stated goal of acquiring petosemtamab and bringing it to hospitals by 2027. The Nordic company – which specializes in cancer antibodies – publicly announced “at least one-billion-dollar annual sales potential by 2029, with multi-billion-dollar annual revenue potential thereafter.”

In his tiny office, overlooking the Barça football stadium, the Spanish biologist answers (in the third person) a question about what percentage of this multi-billion-dollar business he receives. “Eduard Batlle doesn’t get anything,” he affirms. The patent for petosemtamab lists six inventors: the two childhood friends (Hans Clevers and Ton Logtenberg), Batlle himself, as well as the then-scientific director of Merus, Mark Throsby. The other two inventors are the CEO of the Dutch company HUB Organoids – Robert Vries – and the biologist Bram Herpers, who was involved in the trial of hundreds of antibodies with another Dutch company, OcellO BV.

Secrecy is absolute in these kinds of multi-billion-dollar deals involving publicly-traded companies, with numerous confidentiality clauses. This interview with EL PAÍS is the first time that Batlle has spoken publicly since the sale of the molecule, and he cannot even reveal what percentage his center receives. “Neither I nor the Barcelona Institute for Research in Biomedicine can provide information about possible agreements with Merus,” he emphasizes.

Peto is exceptional in the history of biotechnology in Spain. Five entities applied for the patent: the Dutch companies Merus and OcellO BV, the Royal Netherlands Academy of Arts and Sciences — to which Hans Clevers’ Hubrecht Institute belongs — and the two institutions that Batlle is affiliated with: the Barcelona Institute for Research in Biomedicine – where he has worked for 20 years – and the Catalan Institution of Research and Advanced Studies, which is the public foundation of the Government of Catalonia that pays his salary.

The molecule’s three-dimensional image is simple. It’s a kind of capital Y, with two arms to attach to the two points of the tumor cell. Batlle and his colleagues designed it to treat colon cancer, but in initial tests, it worked best in head and neck cancer. This is the seventh-most common cancer worldwide, which causes nearly half-a-million deaths annually. The two ongoing clinical trials are still underway, but the United States has already granted petosemtamab two Breakthrough Therapy designations for mouth and throat cancer. This bureaucratic step allows for the expedited development of an experimental treatment if there’s clear evidence that the antibody works.

Batlle laments “a general problem” in the development of cancer drugs. Experimental drugs are desperately tested on terminally ill patients, in whom several previous rounds of chemotherapy have transformed the tumor’s biology. Petosemtamab is ineffective in these cases of colorectal cancer, which have already been overtreated. However, a recent trial with 50 patients suggests that it’s effective when used as a first or second-line treatment alongside chemotherapy. “The price that Genmab has paid is because they [have] hope that the antibody will also be active in other types of cancer, such as colon cancer,” Batlle points out. Such a development would be disruptive: colon cancer is the third-most-common cancer and the second-deadliest in the world.

The biologist tells the story of petosemtamab while recalling his own: his illiterate grandmother from western Spain opened the pastry shop with his grandfather, a Catalan survivor of a Spanish Civil War concentration camp. He and his family spent sleepless nights making thousands of Three Kings’ Day cakes and Easter cakes. He still remembers the syringes filled with heroin in his neighborhood of Santa Eulalia.

Battle’s parents didn’t encourage him to continue the family pastry business. They only gave him one piece of advice: “Do whatever you want, but study.”

Sign up for our weekly newsletter to get more English-language news coverage from EL PAÍS USA Edition