Orlando, Florida—Research presented from the TIGER study at the 2019 ASH Annual Meeting demonstrated the feasibility of adding pegylated interferon α2b (Peg-IFN) to upfront nilotinib and suggests higher rates of remission in patients with BCR-ABL1–positive chronic myeloid leukemia (CML).

A total of 717 patients with CML were enrolled in this randomized, multi-center, phase 3 trial, including 25 patients enrolled in a pilot phase and 692 patients in the main phase. There were 702 patients who expressed typical BCR-ABL1 transcripts and were eligible for additional molecular follow-up assessments; 15 expressed atypical BCR-ABL1 transcripts.

Patients received nilotinib 300 mg twice daily in the monotherapy arm or nilotinib 300 mg twice daily plus Peg-IFN 30 μg to 50 μg weekly. The primary end point of the study was major molecular response (MMR) at 12 and 18 months. 

Median observation lasted for 41 months, and there was no significant difference in MMR rate between the treatment arms. A total of 477 patients achieved MMR at the end of the induction phase and moved on to receiving maintenance nilotinib or Peg-IFN monotherapy. 

After achieving or sustaining BCR-ABL1 ≤0.01% IS (MR4) for at least 1 year, 199 patients were able to discontinue therapy.

Findings showed that adding Peg-IFN to nilotinib significantly improved the rates of MR4 and MR4.5, which was BCR-ABL1 ≤0.0032%.

The median time to MMR, MR4, and MR4.5 was 5.7 months, 20.9 months, and 33.8 months, respectively, in the nilotinib-monotherapy arm compared with 5.4 months, 12.5 months, and 23.2 months, respectively, in the nilotinib plus Peg-IFN arm.

Among the 199 patients who discontinued therapy, the relapse-free survival rate was 61% at 18 months postdiscontinuation.

Adverse events (AEs) were common in both treatment arms. Special interest AEs of all grades were fatigue (34.6% vs 40% in monotherapy and combination arms, respectively), thrombocytopenia (13.3% vs 18.9%), and alanin aminotransferase elevation (11.0% vs 18.9%). 

“This per protocol interim analysis demonstrates feasibility of the first-line treatment with NIL 2*300 mg/d combined with PEG-IFN 30-50 μg/week,” the investigators stated.

“Peg-IFN, when added upfront to NIL further increases the rates of MR4 and MR4.5, which may translate into higher rates of treatment free remission,” they concluded.—Kaitlyn Manasterski

Hochhaus A, Burchert A, Saussele S, et al. Nilotinib Vs Nilotinib Plus Pegylated Interferon α (Peg-IFN) Induction and Nilotinib or Peg-IFN Maintenance Therapy for Newly Diagnosed BCR-ABL1 Positive Chronic Myeloid Leukemia Patients in Chronic Phase (TIGER Study): The Addition of Peg-IFN Is Associated with Higher Rates of Deep Molecular Response. Presented at: the 2019 ASH Annual Meeting & Exposition; December 7-10, 2019; Orlando, FL. Abstract 495.