Summary
Clinical trials show that tyrosine kinase inhibitor (TKI) treatment can be discontinued in selected patients with chronic myeloid leukaemia (CML). Although updated CML guidelines support such ...procedure in clinical routine, data on TKI stopping outside clinical trials are limited. In this retrospective study utilising the Swedish CML registry, we examined TKI discontinuation in a population‐based setting. Out of 584 patients diagnosed with chronic‐phase CML (CML‐CP) in 2007–2012, 548 had evaluable information on TKI discontinuation. With a median follow‐up of nine years from diagnosis, 128 (23%) discontinued TKI therapy (≥1 month) due to achieving a DMR (deep molecular response) and 107 (20%) due to other causes (adverse events, allogeneic stem cell transplant, pregnancy, etc). Among those stopping in DMR, 49% re‐initiated TKI treatment (median time to restart 4·8 months). In all, 38 patients stopped TKI within a clinical study and 90 outside a study. After 24 months 41·1% of patients discontinuing outside a study had re‐initiated TKI treatment. TKI treatment duration pre‐stop was longer and proportion treated with second‐generation TKI slightly higher outside studies, conceivably affecting the clinical outcome. In summary we show that TKI discontinuation in CML in clinical practice is common and feasible and may be just as successful as when performed within a clinical trial.
Tyrosine kinase inhibitors (TKIs) have profoundly improved the clinical outcome for patients with chronic myeloid leukemia (CML), but their overall survival is still subnormal and the treatment is ...associated with adverse events. In a large cohort‐study, we assessed the morbidity in 1328 Swedish CML chronic phase patients diagnosed 2002–2017 and treated with TKIs, as compared to that in carefully matched control individuals. Several Swedish patient registers with near‐complete nationwide coverage were utilized for data acquisition. Median follow‐up was 6 (IQR, 3–10) years with a total follow‐up of 8510 person‐years for the full cohort. Among 670 analyzed disease categories, the patient cohort showed a significantly increased risk in 142 while, strikingly, no category was more common in controls. Increased incidence rate ratios/IRR (95% CI) for more severe events among patients included acute myocardial infarction (AMI) 2.0 (1.5–2.6), heart failure 2.6 (2.2–3.2), pneumonia 2.8 (2.3–3.5), and unspecified sepsis 3.5 (2.6–4.7). When comparing patients on 2nd generation TKIs vs. imatinib in a within‐cohort analysis, nilotinib generated elevated IRRs for AMI (2.9; 1.5–5.6) and chronic ischemic heart disease (2.2; 1.2–3.9), dasatinib for pleural effusion (11.6; 7.6–17.7) and infectious complications, for example, acute upper respiratory infections (3.0; 1.4–6.0). Our extensive real‐world data reveal significant risk increases of severe morbidity in TKI‐treated CML patients, as compared to matched controls, particularly for 2nd generation TKIs. Whether this increased morbidity may also translate into increased mortality, thus preventing CML patients to achieve a normalized overall survival, needs to be further explored.
Objectives
Treatment‐free remission (TFR) has emerged as a treatment goal in chronic myeloid leukemia in the chronic phase (CML‐CP). Attempts to increase proportion of patients achieving TFR include ...combination of tyrosine kinase inhibitors (TKI) and other drugs. Interferon‐α in addition to TKI has shown promising efficacy but with dose‐dependent toxicity and discontinuations. NordCML007 was initiated to study the efficacy and safety of low dose pegylated IFN‐α (PegIFN‐α) in combination with dasatinib (DAS) in CML‐CP.
Methods
Forty patients with newly diagnosed CML‐CP were given DAS upfront. After month 3 (M3) 15 μg/wk of PegIFN‐α was added and increased to 25 μg/wk from M7 until M15. DAS treatment was continued and adverse events and BCR‐ABL1 qRT‐PCR values were reported yearly after M24. Results from M1 to M18 have previously been published, and here we present long‐term data.
Results
After 5 years of follow‐up, there were no suspected unexpected serious adverse reactions, no increase in serosal effusions, no disease progressions and no CML‐related deaths. Rates of MR3.0 (MMR), MR4.0 and MR4.5 were 84.6%, 64.1% and 51.3% respectively at M60, and 95% of patients reached MMR at some point during the study.
Conclusion
Initial addition of PegIFN‐α to DAS shows good long‐term efficacy without increased toxicity.
Clinical management guidelines on malignant disorders are generally based on data from clinical trials with selected patient cohorts. In Sweden, more than 95% of all patients diagnosed with chronic ...myeloid leukemia (CML) are reported to the national CML registry, providing unique possibilities to compile population-based information. This report is based on registry data from 2002 to 2010, when a total of 779 patients (425 men, 354 women; median age, 60 years) were diagnosed with CML (93% chronic, 5% accelerated, and 2% blastic phase) corresponding to an annual incidence of 0.9/100 000. In 2002, approximately half of the patients received a tyrosine kinase inhibitor as initial therapy, a proportion that increased to 94% for younger (<70 years) and 79% for older (>80 years) patients during 2007-2009. With a median follow-up of 61 months, the relative survival at 5 years was close to 1.0 for patients younger than 60 years and 0.9 for those aged 60 to 80 years, but only 0.6 for those older than 80 years. At 12 months, 3% had progressed to accelerated or blastic phase. Sokal, but not European Treatment and Outcome Study, high-risk scores were significantly linked to inferior overall and relative survival. Patients living in university vs nonuniversity catchment areas more often received tyrosine kinase inhibitors up front but showed comparable survival.
•Patients up to age 70 years with CML treated within a decentralized health care setting had a relative survival close to 1.0.•Sokal, but not EUTOS, score at diagnosis predicted overall and relative survival in a population-based cohort of patients with CML.
Biologic and clinical observations suggest that combining imatinib with IFN-α may improve treatment outcome in chronic myeloid leukemia (CML). We randomized newly diagnosed chronic-phase CML patients ...with a low or intermediate Sokal risk score and in imatinib-induced complete hematologic remission either to receive a combination of pegylated IFN-α2b (Peg–IFN-α2b) 50 μg weekly and imatinib 400 mg daily (n = 56) or to receive imatinib 400 mg daily monotherapy (n = 56). The primary endpoint was the major molecular response (MMR) rate at 12 months after randomization. In both arms, 4 patients (7%) discontinued imatinib treatment (1 because of blastic transformation in imatinib arm). In addition, in the combination arm, 34 patients (61%) discontinued Peg–IFN-α2b, most because of toxicity. The MMR rate at 12 months was significantly higher in the imatinib plus Peg–IFN-α2b arm (82%) compared with the imatinib monotherapy arm (54%; intention-to-treat, P = .002). The MMR rate increased with the duration of Peg–IFN-α2b treatment (< 12-week MMR rate 67%, > 12-week MMR rate 91%). Thus, the addition of even relatively short periods of Peg–IFN-α2b to imatinib markedly increased the MMR rate at 12 months of therapy. Lower doses of Peg–IFN-α2b may enhance tolerability while retaining efficacy and could be considered in future protocols with curative intent.
In chronic myeloid leukemia (CML), combination therapies with tyrosine kinase inhibitors (TKIs) aim to improve the achievement of deep molecular remission that would allow therapy discontinuation. ...IFN-α is one promising candidate, as it has long-lasting effects on both malignant and immune cells. In connection with a multicenter clinical trial combining dasatinib with IFN-α in 40 patients with chronic-phase CML (NordCML007, NCT01725204), we performed immune monitoring with single-cell RNA and T cell receptor (TCR) sequencing (n = 4, 12 samples), bulk TCRβ sequencing (n = 13, 26 samples), flow cytometry (n = 40, 106 samples), cytokine analyses (n = 17, 80 samples), and ex vivo functional studies (n = 39, 80 samples). Dasatinib drove the immune repertoire toward terminally differentiated NK and CD8+ T cells with dampened functional capabilities. Patients with dasatinib-associated pleural effusions had increased numbers of CD8+ recently activated effector memory T (Temra) cells. In vitro, dasatinib prevented CD3-induced cell death by blocking TCR signaling. The addition of IFN-α reversed the terminally differentiated phenotypes and increased the number of costimulatory intercellular interactions and the number of unique putative epitope-specific TCR clusters. In vitro IFN-α had costimulatory effects on TCR signaling. Our work supports the combination of IFN-α with TKI therapy, as IFN-α broadens the immune repertoire and restores immunological function.
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