WASHINGTON — The Food and Drug Administration has released its proposal for naming lower-cost biotech drugs, a critical step in creating a market for the new class of medicines.

Biotech drugs are powerful, injected medicines produced in living cells which are typically much more expensive than traditional chemical-based drugs. Many newer biotech drugs cost more than $100,000 per year and together they account for nearly 30 percent of all U.S. drug spending.

For decades, they have not faced generic competition because the FDA lacked a system to approve cheaper versions until 2012. Earlier this year the agency approved the first so-called “biosimilar.” That’s the industry term for generic biotech drugs, used to indicate that they are not exact copies of the original biologic medicines.

Next week, Novartis is scheduled to launch its biosimilar version of Neupogen, a blockbuster Amgen drug used to boost blood cells in certain cancer patients.

But many questions remain about how the new drugs will be sold and marketed, including whether they can use the same ingredient names as the original products.

Under an FDA proposal, all biotech drugs would be labeled with a four-letter code to help doctors distinguish them from the original versions.

For example, the original drug might be labeled “drug-cznm” and a biosimilar version could be labeled “drug-hixf.” The codes would not have any meaning and would mainly help doctors and pharmacists avoid accidentally switching patients between drugs.

Branded biotech drugmakers have long stressed the safety risks of switching patients to alternate versions of biotech drugs, noting they are not perfect copies of the originals.