Geron eyes 2024 US launch for MDS drug after phase 3 trial shows easing of transfusion burden

Geron Corporation is on track to send its therapy for myelodysplastic syndrome (MDS) to regulators this year after the telomerase inhibitor eased transfusion burden in a phase 3 trial.

Around 40% of the 118 patients given the therapy, called imetelstat, did not require a transfusion at the eight-week mark, compared to 15% of those in the placebo cohort, hitting the study's main endpoint. At 24 weeks, those numbers were 28% and 3%, respectively, meaning a win on the key secondary endpoint of the IMerge trial as well. 

The median transfusion independence duration was one year for imetelstat compared to approximately 13 weeks for placebo, the company estimated.

The readout is enough for the company to power ahead with plans to submit approval applications for the drug to the FDA in mid-2023 and in Europe in the second half of the year. Geron has already overcome one regulatory hurdle in the U.S., having been granted both fast-track designation and a rolling submission by the FDA for transfusion-dependent anemia due to low or intermediate risk of MDS.

Should all go to plan, the company is eyeing a commercial launch of the therapy in the U.S. market in the first half of 2024, followed by the EU by the end of that year.

The trial, of patients with lower risk MDS who are relapsed, refractory or ineligible for erythropoiesis-stimulating agents, also produced no new safety signals, the biotech reported in a release Jan. 4. The most common non-hematologic treatment-emergent adverse events were weakness, COVID-19, peripheral edema, headache, diarrhea and an increase in alanine aminotransferase, an enzyme associated with liver damage. The most frequent hematologic treatment-emergent adverse events were grades 3/4 thrombocytopenia and neutropenia.

The company also pointed to “significant” increases in hemaglobin among patients taking imetelstat, with a median rise of 3.6 grams per deciliter among those who passed the eight-week transfusion independence mark.

Geron hailed the phase 3 results as demonstrating a “highly statistically significant and clinically meaningful difference between imetelstat and the placebo.”

“This milestone is the first of many upcoming catalysts for Geron, with planned U.S. and EU regulatory submissions in 2023, as well as preparations for a potential U.S. commercial launch,” said CEO John Scarlett, M.D. “In addition, in 2024, we expect an interim analysis of the IMpactMF phase 3 trial of imetelstat in relapsed/refractory myelofibrosis.”

“The IMerge phase 3 efficacy results illustrate the depth, breadth and durability of transfusion independence potentially achievable with imetelstat treatment, which could be practice changing, if approved,” said the study’s principal investigator, Uwe Platzbecker, M.D. “ These results are especially encouraging, because today we have limited treatment options for lower risk MDS patients that provide broad and durable transfusion independence.”

Investors seemed convinced, sending Geron’s stock up over 50% to $3.68 per share in the opening hour of trading from a Tuesday closing price of $2.41.