Promising results for new AML treatment
Treatment with CPX-351, a liposomal formulation of cytarabine and daunorubicin, led to a relative improvement in induction response of over 40% compared with conventional 7+3 cytarabine/daunorubicin in patients with secondary acute myeloid leukemia (AML), according to early results from a phase III study.
Celator Pharmaceuticals Inc, the company developing the novel agent, also reported that data on the study’s primary endpoint of overall survival (OS) are anticipated in the first quarter of 2016. Previously reported phase II data showed a survival benefit with CPX-351 versus standard chemotherapy in patients with secondary AML.
“The results are encouraging because this is the third randomized study in which CPX-351 outperformed the control arm of cytarabine plus an anthracycline in overall response rate,” lead author Jeffrey Lancet, M.D., senior member and chief of the Leukemia/Myelodysplasia Program at Moffitt Cancer Center, said in a press release. “With induction therapy for AML, response rate has historically served as a surrogate for overall survival, and these data suggest a clinically meaningful benefit for CPX-351 over standard chemotherapy.”
The open-label phase III study randomized 309 patients with secondary AML in a 1:1 ratio to CPX-351 or 7+3. Patients in the 7+3 arm received 100 mg/m2 of daily cytarabine through continuous infusion for 7 days and 60 mg/m2 of daunorubicin on days 1, 2, and 3. CPX-351 was administered at 100 u/m2 IV on days 1, 3, and 5. The infusion time for the liposome injection was approximately 90 minutes.
The trial enrolled patients aged 60 to 75 years and was conducted at 39 locations in the United States and Canada, including Weill Cornell.
Induction response rates (complete remission [CR] plus complete remission with incomplete hematologic recovery [CRi]) were 47.7% for CPX-351 versus 33.3% for 7+3, yielding a relative benefit of 43.2% with the investigational treatment.
“The magnitude of the CR plus CRi rate increase is promising and we may be one step closer to having a superior treatment option for patients with this devastating disease. The improvement in response rate portends well for a clinically meaningful survival benefit,” Gail Roboz, M.D., associate professor of Medicine and Director of the Leukemia Program at Weill Cornell Medical College and NewYork-Presbyterian, said in the press release.
In January 2015 the FDA granted Fast Track status to CPX-351 for the treatment of elderly patients with secondary AML. The designation was based on the results of two phase II studies, the first of which examined the drug as a first-line treatment for 126 patients with newly diagnosed AML who were aged 60 to 75 years.
In this study, the complete response rate with CPX-351 was 66.7% versus 51.2% with 7+3 (P = .07). Median event-free survival (EFS) and OS were also higher in the CPX-351 arm at 6.5 versus 2.0 months and 14.7 versus 12.9 months, respectively.
Positive data were also observed in a planned subset analysis of patients with secondary AML. There was a 6.0-month, statistically significant OS benefit in this subgroup (12.1 vs 6.1 months; HR = 0.46; P = .01). EFS was 4.5 months with CPX-351 versus 1.3 months with standard chemotherapy (HR = 0.59; P = .08). Response rates were 57.6% versus 31.6%, respectively (P = .06).
This story first appeared in OncLive. Read the full article here.