Adds executive comment in paragraph 7, background in paragraph 10

May 18 (Reuters) - BioMarin Pharmaceutical BMRN.O said on Monday its experimental treatment for a rare genetic condition met one of the two main goals in a late-stage study.

The company was testing its enzyme replacement therapy called BMN 401 in children aged 1 to 12 years with ENPP1 deficiency, a rare, lifelong genetic condition.

The condition is caused by changes in the ENPP1 gene that result in a decrease in plasma inorganic pyrophosphate, leading to damage to blood vessels, soft tissues and bones.

BioMarin said the therapy met a main goal of significant increases in plasma pyrophosphate through 52 weeks, compared with conventional therapy.

However, it did not show an improvement in a measure of the treatment impact in children with rickets, which causes weak bones, the company said.

Children with ENPP1 deficiency typically develop a type of rickets that may cause pain and difficulty with movement.

"We are disappointed that the significant increases in plasma PPi observed with BMN 401 did not translate into meaningful clinical improvements for children with ENPP1 deficiency," said Greg Friberg, chief research and development officer at BioMarin.

BioMarin also said it saw no meaningful improvement in rickets severity, which reflects bone weakness and deformities, or in growth, including height and weight.

The company said it is evaluating the data to determine next steps.

Currently there are no approved treatments for ENPP1 deficiency, and current care focuses on managing symptoms such as bone deformities, pain and movement issues.