Relatives of Henrietta Lacks, an African-American woman whose unwittingly harvested cancer cells spawned revolutionary advances in medicine, have reached a settlement with Thermo Fisher that ends legal action against the biotech firm, lawyers announced Tuesday.

"The parties are pleased that they were able to find a way to resolve this matter outside of court," the Lacks family's attorneys said in a statement.

In 1951, tobacco farmer Lacks was battling cancer. During attempts to cure her shortly before she died at age 31, her abnormally resilient cancer cells were removed from her tumour and used for decades without her family's knowledge.

The cells, dubbed HeLa for the first letters of her first and last names were the first-ever human cells to grow endlessly in the lab - all others harvested up to that point died.

Research using the cells led to Nobel-winning discoveries, and laboratories worldwide used them to develop vaccines - notably against polio -  as well as in cloning, in-vitro fertilisation and many medicines, fueling an industry now worth billions of dollars.

The family knew nothing of Lacks' role until the 1970s and only came to understand its full scope thanks to the work of Rebecca Skloot, author of the 2010 bestseller The Immortal Life of Henrietta Lacks.

The terms of the legal agreement were not disclosed, nearly two years after a complaint was filed in the state of Maryland. 

Thermo Fisher Scientific confirmed the deal, using the same language as the family lawyers Ben Crump and Chris Seeger.

"They treated her like a specimen, like a lab rat," her granddaughter Kimberly Lacks said in 2021, describing the cell theft as racism.

Tuesday's announcement comes on what would have been Henrietta Lacks's 103rd birthday.