(Adds bluebird bio's reference in the analysis, adds name of Vertex and CRISPR Therapeutics' therapy)

April 12 (Reuters) - Vertex Pharmaceuticals Inc and CRISPR Therapeutics AG's one-dose gene editing therapy for sickle cell disease would be cost effective if priced at up to $1.9 million, an influential U.S. drug pricing group said on Wednesday.

The two companies are hoping to get approval for the world's first therapy based on Nobel prize-winning CRISPR technology, for two types of blood disorders - sickle cell disease (SCD) and transfusion-dependent beta thalassemia.

They expect to potentially cure SCD through a single dose of the therapy, exa-cel. SCD is a genetic disorder that causes strokes, organ damage, severe pain and early death and affects roughly 100,000 people in the United States.

In its draft report, the Institute for Clinical and Economic Review (ICER) said a price range between $1.2 million and $1.7 million annually would meet some commonly used thresholds for cost effectiveness, in the health care system perspective.

The analysis also refers to bluebird bio Inc's sickle cell experimental gene therapy lovo-cel.

ICER is not a government agency and has no say on the drug prices that manufacturers set, but many large health insurers take its reports into account when they negotiate prices with drug manufacturers and determine patient access.

Taking into account broader societal benefits of curing the disease, ICER said a price range between $1.3 million and $1.9 million would be cost effective.

Gene therapies have been pricey and their list prices have crossed the million-dollar mark in recent years.

Last year, Australian drugmaker CSL Ltd set the list price of its gene therapy for blood disorder hemophilia B at a record $3.5 million, while bluebird bio priced its gene therapy for beta thalassemia at $2.8 million.

More than half a dozen companies are developing cutting edge gene therapies for sickle cell disease after ignoring it for decades, despite calls from patient advocates to do more.

SCD occurs among about 1 out of every 365 Black or African-American births, according to the U.S. Centers for Disease Control and Prevention estimates.

Novartis AG, Sangamo Therapeutics and CRISPR Therapeutics and Vertex Pharmaceuticals are some of the drugmakers working on a gene therapy for SCD.

(Reporting by Manas Mishra, Raghav Mahobe and Sriparna Roy in Bengaluru; Editing by Shinjini Ganguli, Sonali Paul and Krishna Chandra Eluri)