Quality-adjusted Time Without Symptoms of disease or Toxicity (Q-TWiST) analysis of CPX-351 versus 7 + 3 in older adults with newly diagnosed high-risk/secondary AML

Abstract

Background: CPX-351 (United States: Vyxeos®; Europe: Vyxeos® Liposomal), a dual-drug liposomal encapsulation of daunorubicin and cytarabine in a synergistic 1:5 molar ratio, is approved by the US FDA and the EMA for the treatment of adults with newly diagnosed therapy-related acute myeloid leukemia or acute myeloid leukemia with myelodysplasia-related changes. In a pivotal phase 3 study that evaluated 309 patients aged 60 to 75 years with newly diagnosed high-risk/secondary acute myeloid leukemia, CPX-351 significantly improved median overall survival versus conventional 7 + 3 chemotherapy (cytarabine continuous infusion for 7 days plus daunorubicin for 3 days), with a comparable safety profile. A Quality-adjusted Time Without Symptoms of disease or Toxicity (Q-TWiST) analysis of the phase 3 study was performed to compare survival quality between patients receiving CPX-351 versus conventional 7 + 3 after 5 years of follow-up.

Methods: Patients were randomized 1:1 between December 20, 2012 and November 11, 2014 to receive induction with CPX-351 or 7 + 3. Survival time for each patient was partitioned into 3 health states: TOX (time with any grade 3 or 4 toxicity or prior to remission), TWiST (time in remission without relapse or grade 3 or 4 toxicity), and REL (time after relapse). Within each treatment arm, Q-TWiST was calculated by adding the mean time spent in each health state weighted by its respective quality-of-life, represented by health utility. The relative Q-TWiST gain, calculated as the difference in Q-TWiST between treatment arms divided by the mean survival of the 7 + 3 control arm, was determined in order to evaluate results in the context of other Q-TWiST analyses.

Results: The relative Q-TWiST gain with CPX-351 versus 7 + 3 was 53.6% in the base case scenario and 39.8% among responding patients. Across various sensitivity analyses, the relative Q-TWiST gains for CPX-351 ranged from 48.0 to 57.6%, remaining well above the standard clinically important difference threshold of 15% for oncology.

Conclusions: This post hoc analysis demonstrates that CPX-351 improved quality-adjusted survival, further supporting the clinical benefit in patients with newly diagnosed high-risk/secondary acute myeloid leukemia. Trial registration This trial was registered on September 28, 2012 at www.clinicaltrials.gov as NCT01696084 ( https://ichgcp.net/clinical-trials-registry/NCT01696084 ) and is complete.

Keywords: Acute myeloid leukemia; Chemotherapy; Quality-of-life; Relapse; Survival; Toxicity.

Conflict of interest statement

J.E.C. has received consulting fees from Astellas Pharma, Daiichi Sankyo, Jazz Pharmaceuticals, Novartis, and Pfizer, and research funding from Arog, Astellas Pharma, Daiichi Sankyo, Jazz Pharmaceuticals, Novartis, and Pfizer. T.L.L. has received institutional research funding from AbbVie, Aptevo, Astellas Pharma, Bio-Path Holdings, Celgene, Celyad, Genentech-Roche, Gilead Sciences, Incyte, Jazz Pharmaceuticals, Mateon Therapeutics, Ono Pharmaceuticals, Pfizer, Prescient Therapeutics, Seattle Genetics, Tolero Pharmaceuticals, and Trovagene. G.L.U. has received consulting fees from Jazz Pharmaceuticals and Genentech, and honoraria from Astellas Pharma. R.J.R. and S.F. are employees of and hold stock ownership/options in Jazz Pharmaceuticals. J.E.L. has received consulting fees from Jazz Pharmaceuticals, Agios, Pfizer, and Daiichi Sankyo.

© 2021. The Author(s).

Figures

Fig. 1

Comparison of relative Q-TWiST gains across sensitivity analysis variations. Parameter variations in the Q-TWiST calculation included population (ITT population or safety population), type of toxicity (any grade 3 to 4 AEs or only treatment-related grade 3 to 4 AEs), TOX state health utility weight (0, 0.5, and 1.0), and REL state health utility weight (0, 0.5, and 1.0). For all analyses, TWiST state health utility weight was kept at a constant of 1.0. Across the sensitivity analyses, the relative Q-TWiST gains for CPX-351 versus 7 + 3 were consistently above the clinically important difference of 15% (shown by the yellow line). Q-TWiST, Quality-adjusted Time Without Symptoms of disease or Toxicity; ITT, intent-to-treat; AE, adverse event; TOX, time with any grade 3 or 4 AE or before relapse; REL, time after relapse; TWiST, time in remission and without relapse or grade 3 or 4 AEs