Swiss drug giant Novartis reportedly fired chief scientific officer Brian Kaspar and head of research Allan Kaspar in its affiliate AveXis over charges that they manipulated research data in connection with an FDA application for a gene therapy drug.

An August press release from Novartis said that Kaspar Brothers were relieved from duties as early as May this year. Several other researchers at Avexis were also let go. Novartis bought AveXis for $8.7 billion in April 2018.

Meg Tirrell filed this report for CNBC:

Though Novartis didn’t specify the reason for their departure, they and a few other scientists were fired in connection with data manipulation brought to light last week by the Food and Drug Administration, according to the person, who declined to be named because an investigation is ongoing.

The FDA threatened to take civil or criminal action against Novartis, saying Aug. 6 the drugmaker used data it knew was inaccurate in its application for a $2.1 million gene therapy, Zolgensma, which was approved in May. Zolgensma treats the rare and devastating childhood disease spinal muscular atrophy and is considered a breakthrough as one of the first gene therapy drugs approved in the U.S.

Novartis and the FDA both said the manipulation didn’t affect the evidence supporting Zolgensma’s safety and efficacy and that the drug should remain on the market. The data in question involved a way of testing the potency of the drug during its early development, Novartis said.

The FDA said its review of the therapy may have been extended if it had the information before approval, on May 24.

Novartis Chief Executive Officer Vas Narasimhan said the company immediately began investigating the issue when it uncovered it and waited to tell the FDA until it had “the best information and technical analysis, which we did promptly on completion on June 28.”