University of Washington trial testing Rylaze in adult ALL is suspended for safety review

A phase II trial testing dose-adjusted DA-EPOCH chemotherapy, with or without rituximab, plus recombinant Erwinia asparaginase (JZP458, marketed as Rylaze) has been suspended. The ClinicalTrials.gov record, last updated September 29, 2026, lists the reason as "Safety Review."

The study, registered under NCT06738368, is sponsored by the University of Washington with Jazz Pharmaceuticals as a collaborator. Its start date is listed as May 8, 2026 (actual). The trial was first posted on December 17, 2024, with an estimated primary completion date of January 31, 2028 and estimated study completion of July 30, 2028.

The trial targets adults with newly diagnosed Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia or T-cell ALL. The single-site study is designed to test how well DA-EPOCH chemotherapy with or without rituximab plus JZP458 works in these newly diagnosed patients.¹ Under the protocol, patients receive etoposide, doxorubicin and vincristine intravenously over 96 hours on days 1-4, cyclophosphamide over 1 hour on day 5, oral prednisone twice daily on days 1-5, and JZP458 intramuscularly every 2-3 days on days 7-21 for up to 7 doses per cycle¹, with cycles repeating every 21 days for up to 8 cycles absent disease progression or unacceptable toxicity¹.

The trial's primary outcome is measurable residual disease negativity after 4 cycles of treatment, measured by multi-parameter flow cytometry and assessed according to National Comprehensive Cancer Network response criteria¹. Enrollment is estimated at 30 participants at a single U.S. site, the Fred Hutch/University of Washington Cancer Consortium in Seattle, Washington¹. No further detail on the nature of the safety concern is included in the record.