Rocket Pharmaceuticals' shares jumped ahead of the opening bell after the biotechnology company said it was aligned with the Food and Drug Administration on the path forward for its pivotal phase 2 trial of a treatment for Danon disease.

In premarket trading, the shares were 5.1% higher at $3.60. As of Monday's close, the stock was up 20% over the last three months.

Rocket said an FDA review of initial safety data supports continued enrollment and dosing under a modified protocol in its trial of RP-A501. It said it is aligned with the agency on continued enrollment, dosing and key elements of the study.

Clinical data reviewed by the FDA included results from the first three patients treated under the modified protocol. All three completed at least four weeks of follow-up and had been discharged following protocol-specified observation, and no clinical or laboratory evidence of thrombotic microangiopathy or capillary leak syndrome had been observed, Rocket said.

The FDA confirmed continued enrollment and dosing under the modified protocol at the recalibrated dose. It also confirmed that the study population will include 12 male patients treated with RP-A501, with the first three patients treated at the recalibrated dose counting toward the study population, Rocket said.

The company said it expects to complete dosing of the remaining patients by mid-2027.

Danon disease is a rare genetic disorder that affects many organ systems, especially the cardiovascular, skeletal and central nervous systems.