ENESTnd Update: Nilotinib (NIL) Vs Imatinib (IM) In Patients (pts) With Newly Diagnosed Chronic Myeloid Leukemia In Chronic Phase (CML-CP) and The Impact Of Early Molecular Response (EMR) and Sokal Risk At Diagnosis On Long-Term Outcomes (2013)

Abstract Introduction Frontline NIL continues to show benefit over IM in pts with Philadelphia chromosome-positive (Ph+) CML-CP, with higher rates of major molecular response (MMR; BCR-ABLIS ≤ 0.1%) and MR4.5 (BCR-ABLIS ≤ 0.0032%), lower rates of progression to accelerated phase (AP)/blast crisis (BC) and fewer new BCR-ABL mutations on treatment in the Evaluating Nilotinib Efficacy and Safety in Clinical Trials–Newly Diagnosed Pts (ENESTnd) trial. Here, we report data with a minimum follow-up (f/u) of 4 y; updated data based on 5 y of f/u will be presented. Methods Adults with newly diagnosed Ph+ CML-CP (N = 846) were randomized to NIL 300 mg twice daily (BID; n = 282), NIL 400 mg BID (n = 281), or IM 400 mg once daily (QD; n = 283). Progression and overall survival (OS) events were collected prospectively during study f/u, including after discontinuation of study treatment. Efficacy in the NIL 300 mg BID and IM arms was evaluated based on achievement of EMR (BCR-ABLIS ≤ 10% at 3 mo). Results At 4 y, ≥ 87% of pts remained on study in each arm and 57%-69% remained on core treatment (Table). Rates of MMR and MR4.5 by 4 y were significantly higher with NIL vs IM. Significantly fewer pts progressed to AP/BC on NIL vs IM (on core treatment: 0.7%, 1.1%, and 4.2%; on study: 3.2%, 2.1%, and 6.7% [NIL 300 mg BID, NIL 400 mg BID, and IM arms, respectively]). Of 17 pts across the 3 arms who progressed on core treatment, 11 (65%) had never achieved complete cytogenetic response and none had achieved MR4.5. Fewer mutations have emerged in the NIL arms vs the IM arm; in y 4, mutations emerged in 2 pts (1 pt with T315I on NIL 300 mg BID; 1 pt with F317L on IM). More pts achieved EMR in the NIL 300 mg BID arm vs the IM arm (91% vs 67%). Pts with EMR had significantly higher rates of progression-free survival (PFS) and OS at 4 y vs pts with BCR-ABL &gt; 10% at 3 mo. Among pts with BCR-ABL &gt; 10% at 3 mo, more progressions to AP/BC occurred in the IM arm (n = 14) vs the NIL 300 mg BID arm (n = 2); half of these pts progressed between 3 and 6 mo. In pts with intermediate or high Sokal risk, PFS and OS at 4 y were higher in both NIL arms vs the IM arm. No new safety signals were detected. Selected cardiac and vascular events were more common on NIL vs IM (by 4 y, peripheral arterial occlusive disease [PAOD] in 4 [1.4%], 5 [1.8%], and 0 pts; ischemic heart disease [IHD] in 11 [3.9%], 14 [5.1%,] and 3 [1.1%] pts; and ischemic cerebrovascular events in 3 [1.1%], 5 [1.8%], and 1 [0.4%] pts in the NIL 300 mg BID, NIL 400 mg BID, and IM arms, respectively). In the NIL 300 mg BID arm, 2 of 11 IHD events occurred between 3 and 4 y (all 4 PAOD events occurred in the first 2 y). In the NIL 400 mg BID arm, 2 of 5 PAOD events and 3 of 14 IHD events occurred between 3 and 4 y. Most pts (7 of 9) with a PAOD event on NIL were at high risk due to a combination of baseline risk factors. Conclusions NIL, a standard-of-care frontline therapy option for newly diagnosed CML-CP pts, affords superior efficacy compared with IM, including higher rates of EMR (which is associated with improved long-term outcomes), higher rates of MR4.5 (a key eligibility criterion for many studies of treatment-free remission), and a lower risk of disease progression. NIL continues to show good tolerability with long-term f/u. While selected cardiac and vascular events (including PAOD) are slightly more frequent on NIL vs IM, no increase in annual incidence of these events over time has been observed. Disclosures: Saglio: ARIAD: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Celgene: Consultancy, Honoraria. Hochhaus:Ariad: Research Funding; Bristol Myers Squibb: Research Funding; Novartis: Research Funding; Pfizer: Research Funding. Hughes:Ariad: Consultancy, Honoraria; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; CSL: Research Funding. Clark:Pfizer: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Novartis: Honoraria, Research Funding, Speakers Bureau. Nakamae:Bristol Myers Squibb: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding, Speakers Bureau, travel/ accomodations/ meeting expenses Other. Kim:BMS, Novartis,IL-Yang: Honoraria; Pfizer: Consultancy, Research Funding. Etienne:Pfizer: Membership on an entity’s Board of Directors or advisory committees; Bristol Myers Squibb: Consultancy, Membership on an entity’s Board of Directors or advisory committees; novartis: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Ariad: Membership on an entity’s Board of Directors or advisory committees. Flinn:Novartis: Research Funding. Lipton:Novartis: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers Squibb: Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding, Speakers Bureau; Ariad: Equity Ownership, 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. Moiraghi:Bristol Myers Squibb: Speakers Bureau; Novartis: Speakers Bureau. Fan:Novartis: Employment. Menssen:Novartis: Employment. Kantarjian:Novartis: Research Funding; Pfizer: Research Funding; Bristol Myers Squibb: Research Funding; ARIAD: Research Funding. Larson:Pfizer: Consultancy; Novartis: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy.