Rocket Pharmaceuticals (RCKT) is blasting off.

All after the company reached an “alignment” with the U.S. FDA over its mid-stage trial design for its Danon disease therapy, RP-A501, for which there are no US FDA-approved treatments.

As noted by Barron’s, “The pharmaceutical company said Tuesday that it had reached an agreement with the FDA to support the Phase 2 trial of R-A501 for Danon disease, which is potentially fatal inherited cardiomyopathy. This disease impacts about 15,000 to 30,000 people in the U.S. and U.K.”

With that, the stock is up 37% to $5.69 on the day on a volume spike to 20.67 million shares, as compared to daily average volume of 601,030.

Needham analysts have a buy rating on the RCKT stock, with a price target of $53.  William Blair analysts also have an outperform rating on the stock, noting, “We view Rocket’s alignment with the FDA regarding its Phase II pivotal trial of RP-A501 positively and believe it is in line with management’s previous guidance and our expectations.”