🟠 Moderate Evidence
A new long-acting interferon treatment has demonstrated efficacy in patients with essential thrombocythemia across all genetic variants, according to results from the first North American study of ropeginterferon alfa-2b-njft. The EXCEED-ET trial, published in The Lancet Regional Health – Americas, found that 61% of patients achieved complete hematological response by month 12.
Key takeaways
- 61% of patients achieved complete blood count normalization by 12 months
- Treatment worked equally well across JAK2, CALR, and MPL gene mutations
- Most side effects were mild to moderate and manageable
- First North American data confirms European findings
Study at a Glance
| Source | The Lancet Regional Health – Americas |
| Study type | Single-arm, multicentre study |
| Sample size | N = 52 patients |
| Population | Adults with essential thrombocythemia |
| Country | United States and Canada |
Response Rates by Genetic Mutation Type
Complete hematological response at 12 months across driver mutations
Source: The Lancet Regional Health – Americas, 2026 | Georgian Medical Journal News
First North American Evidence for Long-Acting Interferon
The EXCEED-ET study represents the first comprehensive evaluation of ropeginterferon alfa-2b-njft in North American patients with essential thrombocythemia. Essential thrombocythemia is a rare blood cancer characterized by overproduction of platelets, affecting approximately 1-2 people per 100,000 annually according to the National Cancer Institute.
Dr. Ruben Mesa, lead investigator at UT Health San Antonio, reported that the treatment demonstrated “substantial efficacy across all driver mutations.” The study enrolled 52 patients across multiple centers in the United States and Canada, with a median follow-up of 18 months. For more research on new studies in hematology, our archives provide comprehensive coverage.
Consistent Efficacy Across Genetic Variants
One of the most significant findings was the treatment’s effectiveness regardless of the underlying genetic mutation driving the disease. Among patients with JAK2 mutations—the most common variant affecting about 60% of essential thrombocythemia cases—65% achieved complete hematological response. Patients with CALR mutations showed 60% response rates, while those with MPL mutations had 50% response rates.
“The consistent response across mutation types is particularly encouraging,” noted Dr. Claire Harrison, consultant hematologist at Guy’s and St Thomas’ Hospital, who was not involved in the study but has extensive experience with myeloproliferative neoplasm treatment guidelines. The molecular response data showed that 47% of evaluable patients achieved at least a 50% reduction in their mutation burden.
Safety Profile Confirms European Experience
The safety profile observed in EXCEED-ET was consistent with previous European studies of ropeginterferon. The most common adverse events were flu-like symptoms (73% of patients), fatigue (54%), and injection site reactions (35%). Most events were grade 1-2 severity and manageable with standard supportive care measures.
Serious adverse events occurred in 15% of patients, with no treatment-related deaths reported. The FDA’s drug safety monitoring protocols were followed throughout the trial. Discontinuation due to adverse events occurred in only 12% of patients, suggesting good overall tolerability. Our clinical updates section regularly covers safety data from ongoing hematology trials.
Implications for Clinical Practice
The results support ropeginterferon as a viable treatment option for essential thrombocythemia patients across North America. The drug offers the advantage of less frequent dosing compared to conventional interferon, with injections required only every two weeks initially, extending to monthly or longer intervals for some patients.
“These North American data confirm the drug’s efficacy and provide clinicians with confidence in its use across diverse patient populations,” according to Dr. Srdan Verstovsek, professor of leukemia at MD Anderson Cancer Center. The National Comprehensive Cancer Network guidelines are expected to incorporate these findings in their next update.
Treatment demonstrated substantial molecular responses with 47% of evaluable patients achieving at least 50% reduction in mutation burden
— Dr. Ruben Mesa, UT Health San Antonio (The Lancet Regional Health – Americas, 2026)
What this means
Frequently asked questions
How does ropeginterferon differ from standard interferon?
Ropeginterferon is a long-acting formulation that requires less frequent injections—every two weeks initially compared to three times weekly for standard interferon. It also has an improved side effect profile with reduced flu-like symptoms.
Which patients are eligible for this treatment?
The study included adults with essential thrombocythemia across all genetic variants (JAK2, CALR, MPL mutations). Patients must meet standard diagnostic criteria and have adequate organ function.
When will this treatment be widely available?
Ropeginterferon alfa-2b-njft is already FDA-approved for polycythemia vera and is being evaluated for essential thrombocythemia. Regulatory submission based on these results is expected in 2026.
The EXCEED-ET results provide compelling evidence for expanding ropeginterferon use beyond polycythemia vera to essential thrombocythemia patients. With consistent efficacy across genetic variants and manageable side effects, this treatment addresses a significant unmet need in rare blood cancer care. The data will likely influence treatment guidelines and provide patients with a valuable new therapeutic option.
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Medically reviewed by Prof. Giorgi Pkhakadze, MD, MPH, PhD. Spotted an error? Contact the editorial team.
