FDA Casts Doubts On Geron's Blood Cancer Drug, But Analyst Sees High Probability For Imetelstat's Potential Approval For MDS Anemia Treatment

The FDA’s Oncologic Drugs Advisory Committee will meet virtually on March 14, 2024, to review Geron Corporation’s GERN imetelstat application seeking approval for transfusion-dependent anemia in adult patients with lower-risk Myelodysplastic Syndromes (MDS).

June 16, 2024, is the PDUFA date for imetelstat NDA for transfusion-dependent anemia in adult patients with lower-risk MDS.

The injectable drug imetelstat was being studied in patients with lower-risk myelodysplastic syndromes, a type of blood cancer that requires frequent blood transfusions for managing anemia.

On Tuesday, FDA’s staff flagged concerns related to its Phase 3 trial, according to the FDA briefing documents.

“FDA acknowledges that the results of Study MDS3001-Phase 3 met the statistical goals for the primary endpoint of 8-week red blood cell – transfusion independence (RBC-TI) and key secondary endpoint of 24-week RBC-TI, but the following:

• It is not clear that the magnitude and durability of RBC-TI outweigh the risks of treatment with imetelstat for patients with lower-risk MDS.
•  The HI-E, CR, PR, and OS results are not supportive of a disease-modifying treatment effect.
•  The patient-reported outcomes are not supportive of a treatment effect.”

The document notes that the clinical meaningfulness of an 8-week RBC-TI period in the context of lower-risk MDS is uncertain.

“FDA requires collection and submission of OS data in oncology clinical trials to assess clinical benefit. Furthermore, one argument for therapeutically targeting transfusion-dependent anemia in subjects with lower-risk MDS is that higher RBC transfusion density has been reported to correlate with decreased overall survival,” the FDA staff noted.

According to Needham’s expert analysis, there is around 80-85% likelihood of a favorable AdComm vote for imetelstat due to its risk/benefit profile. 

The analyst highlights that if the vote is positive, the FDA will likely grant full approval by the PDUFA date.

Citing the expert, Needham notes that the long duration of transfusion independence in responders and disease-modifying characteristics of imetelstat are particularly compelling.

Price Action: GERN shares are down 18.50% at $1.745 on the last check Tuesday.

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