By Sahil Pandey

July 20 (Reuters) - Scholar Rock SRRK.O said on Monday a European Union opinion on its experimental spinal muscular atrophy treatment could be pushed to later this year, as regulators await the U.S. FDA's classification of a manufacturing facility included in the drug developer's European filing.

The European Medicines Agency (EMA) is awaiting the U.S. Food and Drug Administration's classification of Scholar Rock's Catalent Indiana fill-finish facility following an April inspection, the company said.

• A favorable FDA reclassification of the facility could clear the way for the EMA's Committee for Medicinal Products for Human Use to issue an opinion on the drug — apitegromab — later this year, said Scholar Rock.

• If the facility is not cleared, the company plans to work with European regulators to advance the application using a second fill-finish facility already included in its U.S. regulatory filing.

• Scholar Rock said the second site makes commercial products and is in good standing with U.S. and European regulators.

• CEO David Hallal said Scholar Rock remains confident it can complete the European review process using either manufacturing site.

• The company's shares were down about 1% midday.

• The FDA is reviewing apitegromab and is expected to decide on Scholar Rock's application by September 30, 2026.

• UBS analyst Michael Yee said the delay was expected because the European filing included only the Catalent facility, but added this was not a risk to the program, citing trial data showing improved motor function in patients treated with the drug.

• Spinal muscular atrophy is a rare genetic disease that causes progressive muscle weakness and can affect movement, swallowing and breathing.