Trubion Pharmaceuticals and Facet Biotech have presented the positive data from a phase 1 study of TRU-016 in patients with relapsed and refractory chronic lymphocytic leukemia (CLL) at the 2009 American Society of Hematology (ASH) Annual Meeting. TRU-016 is a CD37-directed Small Modular ImmunoPharmaceutical (SMIP) protein therapeutic in development for the treatment of B-cell malignancies.
A total of 33 patients were enrolled in the phase 1 TRU-016 dose escalation trial. A majority of patients (20/33) had high-risk genomic features associated with a poor prognosis and had received multiple prior therapies. Evidence of TRU-016 biological activity was seen beginning with patients dosed at the 0.3mg/kg dose level, including in high-risk patients.
Partial response (PR) was observed in five patients, including one patient with the 17p deletion cytogenetic abnormality. Partial response was determined following investigator assessment and the two-month confirmation of these responses is pending. Two patients with leukemia cutis experienced clearing, one complete and one partial. At the 10mg/kg dose, four of five patients with elevated peripheral lymphocyte counts were reduced to normal levels. A total of 16 serious adverse events have been reported. The maximum tolerated dose (MTD) has not yet been reached.
Scott Stromatt, senior vice president and chief medical officer at Trubion, said: “TRU-016 continues to demonstrate activity in clinical trials, and it has the potential to be a meaningful therapeutic. Because it targets CD37, TRU-016 uses a different mechanism of action than currently available CD20-directed therapies. There is significant clinical need for effective therapies in CLL without toxicity burdens, especially given that the median age of CLL patients is over 65 years of age.”
Mark Rolfe, senior vice president and chief scientific officer at Facet Biotech, said: “We are pleased with the promising preliminary data from the ongoing phase 1 trial of TRU-016 in CLL and are excited about expanding the scope of the drug’s clinical development program. We have worked closely with our partners at Trubion to craft a robust development plan for TRU-016, which includes additional clinical trials in other B-cell malignancies, and we look forward to providing an update on our progress in the early part of 2010.”
Also at ASH, data were presented from a preclinical study of Trubion’s proprietary TRU-ADhanCe technology. TRU-ADhanCe technology is a proprietary, additive method designed to enhance the potency of existing therapies that work through Fc-directed or antibody-directed cellular cytotoxicity (ADCC).