The Food and Drug Administration has approved the first in a class of generic drugs that are made from living cells instead of chemical compounds.

So-called biosimilar drugs "are complex medications made or extracted from living cells, blood components and tissue," The Wall Street Journal says.

The newspaper adds: "Biosimilars, unlike traditional generics, aren't precisely identical to the brand drug.

The FDA says biosimiliars must have no "clinically meaningful differences" in safety or effectiveness and must work in the same way as the drugs they are meant to substitute.

The FDA said Friday it has approved the first biosimilar, a drug called Zarxio that is made by Novartis AG's Sandoz unit and meant to boost white blood cells in chemotherapy patients.

As NPR's Rob Stein reports, the decision is expected to open the door to getting many more, less costly versions of expensive drugs on the market.

Zarxio is a generic version of a drug that costs more than $3,000 for a one-month regimen. The biosimilar version costs about $1,000.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.