scorecardresearch Skip to main content

Flagship’s latest startup aims to develop drugs with fewer side effects

Ampersand Biomedicines has launched with $50 million from the Cambridge firm to design medicines that better target the site of a disease than existing treatments

Avak Kahvejian is chief executive and cofounder of Ampersand Biomedicines, a Boston biotech startup that wants to make drugs with fewer side effects.Flagship Pioneering

Anyone who has listened to a drug commercial knows that the benefits of most medications come with a laundry list of potential complications and side effects. One reason for that is because it’s hard to get a drug to only target parts of the body affected by a disease.

A new biotech startup in Boston believes it has a solution to that problem. By pairing a drug with a molecular homing beacon so that it only works where intended, Ampersand Biomedicines hopes to create safer, more effective medicines.

The company launched Tuesday with $50 million from Flagship Pioneering, a Cambridge life science firm that creates and funds its own startups. Ampersand’s 33 employees are based in a new lab space shared with two other Flagship-founded startups in the former Boston Globe headquarters in Dorchester — a development now called Southline Boston.


“It’s a huge space, so it’s quite empty right now,” said Ampersand chief executive and cofounder Avak Kahvejian.

The company was founded in 2020 to figure out how to get drugs to “work where they’re needed, as opposed to where they’re not needed,” said Kahvejian, who is also a general partner at Flagship. He hopes to improve upon existing medicines and also make new ones. “If we do it right, we can improve existing medicines but also allow for new targets…to be accessible,” he added.

Flagship is known for making bold bets on new technologies that could be used to discover or design therapies for a broad swath of diseases. Its biggest success is Moderna, the Cambridge messenger RNA vaccine company that developed a COVID-19 vaccine and is now working on mRNA medicines for a variety of infectious diseases, genetic conditions, cancer, and more.

A technology that helps drugs home in on their targets to minimize side effects could have equally broad applications. A patent application outlines how the startup would target drugs to the intestine, lung, kidney, or skin. Kahvejian, however, said that Ampersand’s interests are not limited to those organs. “The list is continually expanding,” he said.


Ampersand has compiled a map of molecular addresses, which are proteins predominantly found on one type of cell, tissue, or organ in the human body, Kahvejian said. The company is developing biologic drugs, such as antibodies, that target the molecular address with one arm and carry the drug with a second arm — a pairing that inspired the company’s name.

“The ampersand is the symbol of ‘and,’ and we thought it was exemplary of what we’re trying to create,” Kahvejian said.

Ampersand calls its drugs “AND-Body Therapeutics,” but the approach bears similarities to existing technologies such as antibody-drug conjugates, often used to carry potent cancer drugs to tumors, or bispecific antibodies, which can latch onto two molecular targets at one time.

Those technologies have largely been used in treating cancer, where the goal is to kill a tumor. Ampersand is aiming for “significantly broader” applications that could involve delivering a healing therapy to a sick cell, Kahvejian added. Achieving that could require some molecular handiwork, as it’s more complicated than simply attaching a drug to something that zeroes in on the desired molecular address, he explained.

Ampersand is already looking at skin diseases, inflammation in the gut, and turning the immune response up or down in other parts of the body, Kahvejian said, but he wouldn’t say when his company aims to have its first drug in clinical trials.


Ryan Cross can be reached at Follow him on Twitter @RLCscienceboss.