Geron leaps as ODAC backs its MDS drug imetelstat

Shares in Geron have almost doubled in after-hours trading after the FDA’s Oncological Drugs Advisory Committee (ODAC) voted by 12 to 2 in favour of its imetelstat therapy as a treatment for myelodysplastic syndromes (MDS).

The panel concluded that the clinical benefit/risk profile of imetelstat was sufficient to support FDA approval of the antisense drug for treating transfusion-dependent anaemia in adults with lower-risk MDS, despite a sceptical report on the drug by the FDA reviewer. The recommendation covers patients who had failed or were unable to receive treatment with erythropoiesis-stimulating agents (ESAs) for anaemia.

Shares in Geron rose 93% to $3.39 after the meeting, approaching its 52-week high, as investors’ confidence rose for an FDA approval of the first-in-class telomerase inhibitor by the deadline of 16th June.

If that happens, imetelstat will compete with Bristol-Myers Squibb’s erythroid maturation agent Reblozyl (luspatercept), which was cleared to treat anaemia in adults with low-risk, relapsed MDS in 2020 and as a first-line therapy last year. Sales reached $1 billion in 2023.

Despite the FDA’s conclusion that imetelstat’s efficacy data was not convincing and may be outweighed by side effects like cytopenias, most panellists felt that its ability to reduce the need for blood transfusions in this patient group was clinically meaningful and that clinicians were sufficiently skilled in managing those adverse events.

Patients at the meeting explained that the need for regular blood transfusions is one of the most debilitating aspects of MDS and becoming transfusion-free is highly prized.

In the IMerge trial that formed the bedrock of Geron’s marketing application, around 40% of patients given imetelstat were able to become free of red blood cell transfusions at eight weeks, compared to 15% of a placebo group, although, that proportion decreased over time to 31.4% at 16 weeks, 28.0% at 24 weeks, and 13.6% after a year.

Some of the FDA’s advisors also pointed out that MDS generally cannot be cured using current therapies and there are relatively few treatment options after ESAs have been tried. Other drugs used in this second-line setting, including lenalidomide and hypomethylating agents, also tend to cause cytopenias.

“There are few treatment options and significant unmet medical need remains for these patients, particularly among those with difficult-to-treat subtypes of this blood cancer,” said Faye Feller, Geron’s chief medical officer.

“We believe that imetelstat has the potential to be an important new medicine for patients and look forward to continuing our collaboration with the FDA as they complete their review of our New Drug Application,” she added.

GlobalData has predicted that imetelstat could achieve sales of $1.3 billion in the US alone by 2033, assuming that the drug also performs in follow-up indications, such as myelofibrosis. It is now on track to become Geron’s first product, after 30 years of drug development effort.

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