Federal regulators are trying to make it easier to develop cheaper alternatives to powerful drugs that many Americans depend on to treat autoimmune diseases or cancers.

The Food and Drug Administration said Wednesday it has released guidance to simplify studies for biologic drugs and cut unnecessary testing.

Biologic drugs are made from living cells instead of by mixing chemicals. They have led to major advances in treating immune system disorders, eye diseases and some cancers since the late 1990s, but they also are very costly.

For decades, biotech drugmakers argued that their medicines were too complex to be copied by competitors. That finally changed under President Barack Obama’s 2010 health overhaul, which ordered the FDA to create a system for approving “biosimilar drugs.” The industry term arose because scientists insisted it would be impossible to produce exact copies of their biotech drugs.

FDA’s pathway, finally published in 2015, suggests that drugmakers conduct studies showing patients respond similarly to biosimilar versions when compared with the originals.

The latest proposal seeks to ease that standard, which the administration calls an “unnecessary resource-intensive requirement.”