Treatment-Free Remissions in Newly Diagnosed CP CML Patients Treated with the Combination of Nilotinib + Pegylated Interferon Alpha 2a Versus Nilotinib Alone in the National Phase III Petals Trial

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.2553-2553
• Main Authors: Nicolini, Franck E., Etienne, Gabriel, Huguet, Francoise, Guerci-Bresler, Agnès, Charbonnier, Aude, Escoffre-Barbe, Martine, Dubruille, Viviane, Johnson-Ansah, Hyacinthe, Legros, Laurence, Coiteux, Valerie, Cony-Makhoul, Pascale, Lenain, Pascal, Roy, Lydia, Rousselot, Philippe, Guyotat, Denis, Ianotto, Jean-Christophe, Orvain, Corentin, Deconinck, Eric, Caillot, Denis, Turlure, Pascal, Courby, Stephane, Quittet, Philippe, Hermet, Eric, Amé, Shanti, Lapusan, Simona, Morisset, Stephane, Mahon, Francois-Xavier, Rea, Delphine, Dulucq, Stephanie
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-146412

Aims: Combining 2GTKI+pegylated IFN-a (Peg-IFN) represents an attractive approach for first-line treatment of CP CML, while providing somewhat light additional AEs, it induces high rates of deep molecular responses. We evaluated nilotinib (NIL) alone versus NIL+Peg-IFN in newly diagnosed CP-CML patients (pts) in a randomised phase III trial (PETALs, EudraCT 2013-004974-82) and analysed here the proportion of patients reaching Treatment-Free Remission (TFR) and outcome. Methods: Newly diagnosed CP CML pts ≤65 years, without vascular history were randomized 1:1 to get NIL 300 mg BID alone [M0 to M72 (unless TFR), arm A] vs Peg-IFN alone for 30 days (M-1→M0) 30 mg/wk, prior to NIL 300 mg BID + Peg-IFN 30 mg/wk 2 wks, upgraded to 45 mg/wk thereafter, for up to 2 y (M0 to M24, arm B) followed by NIL alone until M72 unless TFR. The primary endpoint was the rate of MR4.5 by M12, and after amendment, the trial was extended to 72 months follow-up in order to add, as a secondary endpoint, the TFR rate in pts reaching MR4.5 ≥2 y. The trigger for treatment resumption was loss of MMR. All molecular assessments were centralised until M36, and in case of TFR, MR4.5 was centrally confirmed at M0 TFR, and further molecular follow-up was then performed locally. All molecular quantifications are expressed as BCR-ABL1/ABL1 (IS) in % with ≥32,000 copies of ABL1 as control in the central lab and in the local labs all involved to the pluri-annual French external quality controls. Results are analysed in intention-to-treat. Results: As previously reported, 200 pts were randomized (99 in A, 101 in B), 130 M and 35 F in each arm, median age of 46 (18-66) y. The median follow-up (FU) since diagnosis is now 47.5 (33.77-62.39) Mo. and the median FU since discontinuation is 9.86 (5.8-23) Mo. in arm A and 15.57 (12.62-22.77) Mo. in arm B. Sokal and ELTS scores were high in 25% and 2.5%, intermediate in 33% and 16.5% and low in 42% and 81% pts respectively, equally balanced. All pts harboured a “Major” BCR transcript. We have previously shown that by M12, the rate of MR4.5 was 15.9% vs 21.5% (primary endpoint met, p=0.049) and that the overall cumulative incidence of MR4.5 was somewhat superior in arm B (54.6 [43.7-65.5] %) vs A (44 [31.5-54] %), p=0.05. Two pts died, one from myeloid blast crisis before TFR (arm A), one from a solid tumour (arm A). Overall, 40 pts (20%) reached the TFR criteria, 21 in arm A with a median FU of 9.86 (5.8-23) Mo. and 19 in arm B with a median FU since Nil