Real-world PROSPER data showed benefits through week 48
Adults with relapsed or refractory mycosis fungoides and Sézary syndrome reported better control of itch, flaking and redness by week 4 of mogamulizumab treatment in the PROSPER study.
Kyowa Kirin, Inc. Announced the results on June 29, 2026, from Princeton, New Jersey. Researchers presented the data at the 6th World Congress of Cutaneous Lymphomas in Montreal, Canada.
PROSPER followed 73 adults with cutaneous T-cell lymphoma subtypes, including 41 with mycosis fungoides and 32 with Sézary syndrome.
Patients also reported better body temperature regulation from week 4. Sleep and health-related quality of life improved from week 12, and quality-of-life gains continued through week 48.
Mean scores improved from baseline to week 48 across key skin symptoms. Itch fell by 2.5 points, flaking by 3.1 points, redness by 3.1 points and pain by 1.7 points.
Standard deviations in the study summary were 3.4 for itch, 3.5 for flaking, 3.5 for redness and 4.4 for pain.
PROSPER patient-reported measures
Investigators collected patient-reported outcomes at baseline and throughout follow-up using three tools: a CTCL-specific symptom diary, the MF/SS-CTCL-QoL questionnaire and the Brief Fatigue Inventory.
Those tools tracked itch, pain, redness, flaking, sleep problems and difficulty regulating body temperature. The quality-of-life questionnaire measured daily impact, while the Brief Fatigue Inventory measured fatigue severity and daily functioning.
Professor Julia Scarisbrick, principal investigator and honorary professor of dermatology at University Hospitals Birmingham NHS Foundation Trust, said: “Cutaneous T-cell lymphoma can affect far more than just the skin, impacting how patients feel and function every day.”
She said the PROSPER findings were encouraging for patients with mycosis fungoides or Sézary syndrome because symptom relief appeared to last.
Mycosis fungoides and Sézary syndrome are subtypes of cutaneous T-cell lymphoma, a rare non-Hodgkin lymphoma. CTCL can appear as patches, plaques, tumours or reddening of the entire skin, and it may spread to lymph nodes, blood or other organs.
PROSPER also assessed fatigue with the Brief Fatigue Inventory. Patients with mycosis fungoides showed little change, but patients with Sézary syndrome reached the minimum important difference threshold in total fatigue scores by week 48.
Susan Thornton, study author and co-CEO of the Cutaneous Lymphoma Foundation, said: “Clinical studies are stronger when they are shaped by the voices and lived experiences of people living with the disease.”
Thornton said collaboration between industry and the patient community can produce more relevant insight into symptom burden, quality of life and day-to-day treatment experience.
Kyowa Kirin, Inc. Is a wholly owned subsidiary of Kyowa Kirin Co. Ltd, which is listed in Tokyo under TSE: 4151.
