Johnson & Johnson has deferred making a decision about whether to drop or commit to Geron’s imetelstat. The inaction means trials of the telomerase inhibitor in myelodysplastic syndromes and relapsed or refractory myelofibrosis will keep moving forward for now, but leaves Geron without reassurance about the drug’s long-term future.
J&J is testing the candidate in two trials with a view to generating data to support decisions about its next steps. Both studies made it through the latest review. In patients with the cancers known as myelodysplastic syndromes, imetelstat delivered safety and efficacy data to support continued development. J&J is pushing ahead in myelofibrosis, too, although the limited look at results from that study features elements to temper enthusiasm.
The spleen volume response rate seen in the myelofibrosis trial is currently less than was seen when potential rivals to imetelstat were trialled. Geron pointed to performance against a range of other outcome measures to argue that the drug may deliver clinical benefits. But, with the data coming seven months after J&J scrapped a low-dose arm, the spleen volume response rate readout adds to concerns that imetelstat will fail to move the needle.
Other aspects of the update also raise questions about J&J’s commitment. Talking to investors last month, Geron CEO John Scarlett, M.D., said J&J could resume enrollment in the higher, 9.4-mg/kg dose cohort. Now though, J&J has opted against doing so. Geron sought to downplay the decision, noting that there are enough patients in the trial already to assess longer-term outcomes.
Geron expects J&J to wait for longer-term data from the myelofibrosis study before making a decision about whether to continue development of imetelstat in the indication. Exactly when that will happen is unclear, with Geron only saying it thinks J&J will make its evaluation “during the next year.”
The decision on how to proceed in myelodysplastic syndromes is more pressing. J&J is currently testing imetelstat in part one of a planned two-part clinical trial. Using data from the 30-patient, single-arm introduction to the study, J&J will decide whether to push ahead into part two, a phase 3, 170-subject randomized, controlled trial. Geron had hoped J&J would kick off the phase 3 in the middle of 2017, but has now pushed back its forecast to the fourth quarter.
Shares in Geron traded up 15% premarket.