Enestnd 4-Year (y) Update: Continued Superiority of Nilotinib Vs Imatinib in Patients (pts) with Newly Diagnosed Philadelphia Chromosome–Positive (Ph+) Chronic Myeloid Leukemia in Chronic Phase (CML-CP)

Pts treated with nilotinib in the ENESTnd phase 3 trial achieved higher and faster rates of major molecular response (MMR, ≤ 0.1% BCR-ABL^IS), deeper molecular responses (MR⁴, ≤ 0.01%^IS and MR^4.5, ≤ 0.0032%^IS), significantly lower rates of progression to accelerated phase/blast crisis (AP/BC), and fewer CML-related deaths compared with imatinib by 1, 2, and 3 y. Here, we report data with a minimum follow-up of 3 y; efficacy and safety data based on longer follow-up of 4 y will be presented to further assess the impact of nilotinib vs imatinib in pts with newly diagnosed Ph+ CML-CP.

Adult pts (N = 846) with newly-diagnosed Ph+ CML-CP were randomized to nilotinib 300 mg twice daily (BID; n = 282), nilotinib 400 mg BID (n = 281), or imatinib 400 mg once daily (QD; n = 283). MMR, MR⁴, MR^4.5, time to progression to AP/BC, progression-free survival (PFS), and overall survival (OS) were evaluated.

Significantly higher rates of MMR, MR⁴, and MR^4.5 by 3 y were achieved in nilotinib- vs imatinib-treated pts (Table). Nilotinib led to the achievement of higher rates of molecular responses regardless of Sokal risk group or age. The difference in the rates of both MR⁴ and MR^4.5 continued to be significantly higher for nilotinib, with the difference in favor of nilotinib increasing from 1 to 3 y (MR⁴: 9%-14% difference by 1 y, 18%-24% difference by 3 y; MR^4.5: 6%-10% difference by 1 y, 13%-17% difference by 3 y). Among patients who achieved MMR, more pts achieved MR⁴ or MR^4.5 on nilotinib 300 mg BID (68%) and nilotinib 400 mg BID (62%) compared with imatinib (49%). No pt in any arm progressed after achieving MR^4.5. Significantly fewer pts progressed to AP/BC on nilotinib vs imatinib (Table). No new progressions occurred on core treatment between the 2-y and 3-y analyses. When events occurring after treatment discontinuation were included, the rates of progression to AP/BC were also significantly lower with nilotinib vs imatinib (Table). Nearly twice as many pts had emergent mutations on imatinib (n = 21) vs either nilotinib arm (n = 11 in each arm), with 5 pts overall developing mutations between 2 and 3 y. OS remained similar in all groups at 3 y, but fewer CML-related deaths occurred in both the nilotinib 300 mg BID (n = 5) and 400 mg BID (n = 4) arms vs imatinib (n = 14). Both drugs were well tolerated. Few new adverse events (AEs) and laboratory abnormalities were observed between 2 and 3 y. Rates of discontinuation due to AEs were 10%, 14%, and 11% in the nilotinib 300 mg BID, nilotinib 400 mg BID, and imatinib arms, respectively.

Nilotinib continues to demonstrate superiority vs imatinib, yielding faster and deeper molecular responses and a significantly decreased risk of progression. Results of ENESTnd support the use of nilotinib as a standard of care option in newly diagnosed adult pts with Ph+ CML-CP and should be considered to replace imatinib as the standard-of-care frontline therapy for patients with Ph+ CML-CP.

Kantarjian:Novartis: Consultancy, Research Funding; BMS: Research Funding; Pfizer: Research Funding. Kim:Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; ARIAD: Research Funding; II-Yang: Research Funding. Clark:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Reiffers:BMS: Expense reimbursement for travel expenses Other; Novartis: Expense reimbursement for travel expenses, Expense reimbursement for travel expenses Other. Nicolini:Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Honoraria, Research Funding, Speakers Bureau; Ariad: Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria. Hughes:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Ariad: Consultancy, Honoraria; CSL: Research Funding. Hochhaus:BMS: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Ariad: Consultancy, Honoraria, Research Funding. Kemp:Novartis Pharmaceuticals Corp: Employment. Fan:Novartis Pharmaceuticals Corp: Employment. Waltzman:Novartis Pharmaceuticals Corp: Employment, Equity Ownership. Saglio:Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy. Larson:Novartis: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Research Funding; Pfizer: Consultancy; Ariad: Consultancy, Research Funding.