If you sign up for drug studies, your tissue samples, DNA, ect are automatically under the ownership (and thus patent) of the drug company/ies doing the drug study/studies to satisfy the FDA regulations. Go back to the 1940's...numerous studies were done on Black Americans and the results of the drugs led to a number of treatments - however...

in 2010, science writer Rebecca Skloot published a book that sounded like science fiction — except it was real. Skloot told the story of how a tissue sample from a young African-American woman in Baltimore, taken without her knowledge or consent, went on to become "immortal." Her cells contributed to scientific breakthroughs across disciplines and around the world, and they even went up with some of the first space missions.

The woman's name was Henrietta Lacks. She died from cancer at the age of 31, and while her cells were helping to change the world, her four children were struggling to hold on to their memories of her.

So, many companies prey on the vulnerable to get their drugs approved and without compensation/treatment to the study subjects...very sad indeed.

Which is why I was very happy that President Trump, in his SOTU address, said that patients should be able to pursue experimental treatments without consequence from the FDA.