Michael Sela, immunologist behind the development of new drugs to treat cancer and MS – obituary

Michael Sela - Weizmann Institute
Michael Sela - Weizmann Institute

Michael Sela, who has died aged 98, was an Israeli scientist whose research led to the development of new drugs to treat cancer and multiple sclerosis.

His breakthroughs came about through a combination of serendipity and years of perseverance. As a young man he had studied under Ephraim Katzir, a biophysicist and future president of Israel who was chiefly interested in the properties of poly-amino acids.

These are long chains of molecules that form the building blocks of proteins. Ephraim Katzir hoped that synthetic poly-amino acids would have useful applications in chemistry, but Sela was more interested in their biological properties. Specifically, he thought they could function as antigens – molecules that would provoke a unique immune response in the body.

In 1967 Sela and two colleagues, Ruth Arnon and Dvora Teitelbaum, attempted to trigger symptoms of multiple sclerosis in lab animals by injecting them with synthetic proteins. The project failed. Eventually, however, it dawned on the researchers that the injections might in fact be suppressing the symptoms of MS rather than causing them.

The drug based on their discovery, sold under the brand name Copaxone, was finally approved for use in America in 1996. Though it did not cure the debilitating autoimmune disease, it made relapses less frequent, reducing disability in the long run.

Today Copaxone generates billions of dollars in revenue for the Israeli drugmaker Teva, and has been approved for use in dozens of countries, Britain included.

Michael Sela was born Mieczyslaw Salomonowicz on February 28 1924, in the Polish town of Tomaszow Mazowiecki. His father owned a successful factory that made high-quality worsted wool yarns and fabrics.

In 1935 the family moved to Romania to escape the increasingly anti-Semitic policies of the Polish government. When the first pogroms began they left for British-controlled Palestine.

Upon arrival in Tel Aviv, 17-year-old Michael worked for several months in a factory that made gauze for the British war effort. Already proficient in Polish, German, Romanian and French, he soon learnt to speak Hebrew and taught himself English by reading with the aid of a dictionary.

After studying Chemistry at the Hebrew University in Jerusalem, he headed for Geneva to study for a PhD, but left to assist in the movement of European Jews – many of them Holocaust survivors – to the newly founded state of Israel.

In 1950 he resumed his career in academia at the Weizmann Institute of Science, where he became a student of Ephraim Katzir. He founded the Chemical Immunology Section in 1963 and served as president of the Institute from 1975 to 1985.

During his time in the laboratory, Sela conducted extensive research into the structure and function of biologically relevant macromolecules such as proteins and nucleic acids. He worked on creating small molecules that would block the receptors on cancer cells, preventing the formation and spread of cancerous tumours.

The drugs developed on the back of this research have been used to treat lung cancer, metastatic colorectal cancer and head and neck carcinomas. Elsewhere, his work on the genetic control of the immune response led to the development of whole new fields in immunology.

The awards and accolades Michael Sela received included the Wolf Prize, the Israel Prize, and the Unesco Albert Einstein Gold Medal. Outside the laboratory he pursued a love of dance and of music, particularly jazz. He was friends with Arthur Rubinstein and served on the board of directors of the international piano competition named in honour of the Polish-American pianist.

Michael Sela’s first wife, Margalit, died in 1975. He is survived by his second wife Sara, and by three daughters.

Michael Sela, born February 28 1924, died May 27 2022