PF411 ENESTOP 192‐WK RESULTS: DURABILITY AND IMPACT ON QUALITY OF LIFE OF TREATMENT‐FREE REMISSION (TFR) FOLLOWING SECOND‐LINE (2L) NILOTINIB (NIL) IN PATIENTS (PTS) WITH CHRONIC MYELOID LEUKEMIA (CML)

• Published in: HemaSphere 2019-06, Vol.3 (S1), p.158-n/a
• Main Authors: Mahon, F.‐X., Boquimpani, C., Takahashi, N., Benyamini, N., Clementino, N.C. D., Shuvaev, V., Lipton, J.H., Turkina, A.G., De Paz Arias, R., Moiraghi, B., Nicolini, F.E., Dengler, J., Sacha, T., Kim, D.‐W., Fellague‐Chebra, R., Acharya, S., Bouard, C., Hughes, T.P.
• Format: Article
• Language: English
• ISSN: 2572-9241; 2572-9241
• DOI: 10.1097/01.HS9.0000559856.05874.69

Background: The ENESTop study (NCT01698905) is evaluating TFR in pts with CML in chronic phase who achieved sustained deep molecular response with 2L NIL. In the primary analysis, 57.9% of pts remained in TFR 48 wks after stopping NIL. Analyses at 144 wks showed durability of TFR. Aims: To assess the maintenance and safety of TFR after a longer follow‐up of 192 wks. Methods: Eligible pts had received ≥3 y of treatment (including >4 wks of imatinib followed by ≥2 y of NIL) and had achieved MR4.5 (BCR‐ABL1 IS ≤0.0032%) on NIL. Pts without confirmed loss of MR4.5 after 1 y of consolidation (CONS) treatment could attempt TFR. NIL was resumed upon loss of major molecular response (BCR‐ABL1 IS ≤0.1%) or confirmed loss of MR4 (BCR‐ABL1 IS ≤0.01%). By the data cut‐off (24 Sep 2018), all pts had either completed ≥192 wks of TFR, resumed NIL, or discontinued the study. Results: At the data cut‐off, of the 126 pts who entered TFR, 56 remained in TFR, 59 had resumed NIL and 11 had discontinued the study. At 192 wks, the TFR rate was 46.0% (58/126; 95% CI, 37.1–55.1%); all but 1 pt were in MR4.5. Of pts in TFR at 144 wks, only 1/61 had lost response (confirmed loss of MR4) by 192 wks; 2 other pts had discontinued due to pt/guardian decision and serious AE (polycythemia vera), respectively. Of pts who resumed NIL, 56/59 (94.9%) and 55/59 (93.2%) regained MR4 and MR4.5, respectively. Of 56 pts who regained MR4, 40 (71.4%) had stable MR4 96 wks later; the remaining 16 had either discontinued