Shares of the Cambridge, Mass., company at last check were off 16% at $49.06.
Bluebird Bio said it would submit its application for the treatment, LentiGlobin, to the U.S. Food and Drug Administration for clearance in late 2022. The company had said earlier that the submission would come in the second half of 2021.
Bluebird Bio cited additional FDA requirements and challenges related to the coronavirus pandemic as reasons for the delay.
SVB Leerink analyst Mani Foroohar lowered his price target to $99 from $133, while keeping an outperform rating on the shares.
Foroohar said the FDA would now require demonstration of comparability of clinical trial and commercial drug product as part of the Biologics License Application analytical package. Bluebird Bio noted that the package would not require additional clinical data.
In addition, Barclays analyst Gena Wang downgraded Bluebird Bio to equal weight from overweight with a $64 price target after the LentiGlobin submission was delayed.
Canaccord analyst John Newman lowered his price target on the company to $86 from $118, while affirming a buy rating on the shares, citing the delayed submission.
Mizuho Securities analyst Difei Yang kept her buy rating on the stock, according to Investors Business Daily.
She said "these delays represent short-term headwinds for Bluebird and we are not too surprised given the complexity of gene therapy manufacturing and evolving requirements for product characterization in the industry."
The analyst retained her $123 price target, saying "we are buyers of the shares on weakness."
Bluebird Bio reported a third-quarter loss of $194.7 million, or $2.94 a share, beating the Zacks consensus forecast for a loss of $3.07 a share. The company reported a loss of $3.73 a share for the year-earlier period.
Revenue totaled $19.3 million, more than twice the $8.9 million of a year earlier but missing the Zacks estimate by 26%