KTX-1001 Elicits Responses in Some With Multiple Myeloma

The investigational oral therapy KTX-1001, also known as gintemetostat, is catching interest as a potential treatment for a subgroup of patients with multiple myeloma, as an expert explained in a recent interview with CURE.

Dr. Saad Usmani, a member of the scientific advisory board of the International Myeloma Foundation and chief of the myeloma service at Memorial Sloan Kettering Cancer Center in New York City, presented results from a phase 1 clinical trial of the drug at the 2025 American Society of Hematology (ASH) Annual Meeting showing that it achieved disease control in 40% of patients with durable responses lasting up to a year.

Usmani sat down for an interview with CURE to discuss KTX-1001 and what research comes next.

CURE: Regarding KTX-1001, for patients with multiple myeloma, what is so significant about the recent trial findings related to this oral therapy?

Dr. Saad Usmani: I think one very important point that we typically make to our patients is that every patient with myeloma is different, not just from the perspective of what health issues or baggage a patient is coming in with when they're diagnosed with myeloma, myeloma is not one disease. It has many different subgroups, biologically, and one of those subtypes is translocation 4;14, it happens in about 10% to 15% of patients, and historically has been a little bit of a more aggressive kind of myeloma, although in more recent years, we've done a good job in improving outcomes even for those patients.

So the significance of KTX-1001, and it’s now called gintemetostat, is that it's an oral pill, and it inhibits that pathway that gets activated in patients with translocation 4;14, so the significance is that that this is a targeted therapy for that particular kind of myeloma patient population.

What were the findings that were presented at ASH regarding this drug?

At ASH, we presented the dose escalation phase 1 part of the study. Whenever we have a new drug, we have to do a clinical trial, start with low doses, see if patients tolerate it, and then gradually escalate the dose in different cohorts. And what we found in this study was that we were starting to see clinical activity in patients, from stable disease to minimal response, and even in patients who did not have translocation 4;14, we saw deep responses. And we are trying to understand how that mechanism is happening, but from a safety standpoint, besides looking at blood counts, we did not see any major high-grade side effects from this oral drug. So really promising to see this kind of treatment making it through the dose escalation portion, and hopefully we can combine it with other treatments for this patient population in the future.

And in terms of patient accessibility and kind of attainability for this treatment, how significant is the fact that this is an oral treatment?

I think it is quite significant because it gives patients the flexibility of taking the pills at home. They don't have to come into the infusion center to receive these treatments, and it also helps in combining it with other potentially infusional or subcutaneous therapies.

What comes next, research-wise?

What comes next is combining this treatment with other myeloma treatments to figure out what's the right recipe to use for translocation 4;14 patients. What we've also learned in the myeloma therapeutics field over the past 15 years is, because myeloma is a complex disease, even though one pathway may be active, there can be subclones where there are other pathways or mechanisms that are causing the disease to proliferate a little bit more or in a different way. So combining different therapies gives better outcomes for myeloma patients, and that's the next step. So you know, we are currently studying a cohort of combining gintemetostat with [Kyprolis (carfilzomib)] another one with the new CELMoD, mezigdomide.

Transcript has been edited for clarity and conciseness.

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