On Thursday, the FDA approved Geron Corporation's ( GERN ) Rytelo (imetelstat) for adult patients with low-to intermediate-1 risk myelodysplastic syndromes (MDS) with transfusion-dependent anemia.

The approval covers patients requiring four or more red blood cell units over eight weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents.

In March, by a 12-to-2 margin, the FDA adcomm panel voted in favor of the benefits of imetelstat, stating that the associated risks and toxicities of the treatment appear to be manageable.

The FDA approval is based on IMerge Phase 3 trial results.

The IMerge trial met its primary and key secondary endpoints, with Rytelo demonstrating significantly higher rates of red blood cell transfusion independence (RBC-TI) versus placebo for at least eight consecutive weeks (Rytelo 39.8%; placebo 15.0%) and at least 24 weeks (Rytelo 28.0%; placebo 3.3%.

RBC-TI was durable and sustained in the Rytelo-treated population, with a median RBC-TI duration for 8-week responders and 24-week responders of approximately one year and 1.5 years, respectively.

In an exploratory analysis of Rytelo-treated patients achieving ≥8-week RBC-TI, median increases in hemoglobin were 3.6 g/dL for Rytelo and 0.8 g/dL for placebo.

Clinically meaningful efficacy results were observed across key MDS subgroups irrespective of ring sideroblast status, baseline transfusion burden, and IPSS risk category.

Imetelstat is Geron's ( GERN ) first commercial treatment in the market. It competes with Bristol Myers Squibb Co's ( BMY )  Reblozyl (luspatercept-aamt), which received an FDA label expansion last year for the same disease indication.

Last January, Geron's ( GERN ) CEO John Scarlett told Reuters that the company anticipates a peak market potential of $1.2 billion in the United States and some key EU countries by 2030.

Price Action: GERN shares are up 25.4% at $4.88 at the last check on Friday.