Hans D. Menssen

Long-term benefits and risks of frontline nilotinib vs imatinib for chronic myeloid leukemia in chronic phase: 5-year update of the randomized ENESTnd trial

In the phase 3 Evaluating Nilotinib Efficacy and Safety in Clinical Trials–Newly Diagnosed Patients (ENESTnd) study, nilotinib resulted in earlier and higher response rates and a lower risk of progression to accelerated phase/blast crisis (AP/BC) than imatinib in patients with newly diagnosed chronic myeloid leukemia in chronic phase (CML-CP). Here, patients’ long-term outcomes in ENESTnd are evaluated after a minimum follow-up of 5 years. By 5 years, more than half of all patients in each nilotinib arm (300u2009mg twice daily, 54%; 400u2009mg twice daily, 52%) achieved a molecular response 4.5 (MR4.5; BCR-ABL⩽0.0032% on the International Scale) compared with 31% of patients in the imatinib arm. A benefit of nilotinib was observed across all Sokal risk groups. Overall, safety results remained consistent with those from previous reports. Numerically more cardiovascular events (CVEs) occurred in patients receiving nilotinib vs imatinib, and elevations in blood cholesterol and glucose levels were also more frequent with nilotinib. In contrast to the high mortality rate associated with CML progression, few deaths in any arm were associated with CVEs, infections or pulmonary diseases. These long-term results support the positive benefit-risk profile of frontline nilotinib 300u2009mg twice daily in patients with CML-CP.

Early molecular response predicts outcomes in patients with chronic myeloid leukemia in chronic phase treated with frontline nilotinib or imatinib

We explored the impact of early molecular response (EMR; BCR-ABL ≤10% on the international scale [BCR-ABL(IS)] at 3 or 6 months) on outcomes in patients with newly diagnosed chronic myeloid leukemia in chronic phase treated with nilotinib or imatinib based on 4 years of follow up in Evaluating Nilotinib Efficacy and Safety in Clinical Trials-Newly Diagnosed Patients. Patients (n = 846) received nilotinib 300 mg twice daily, nilotinib 400 mg twice daily, or imatinib 400 mg once daily. At 3 months, more patients had EMR failure (ie, BCR-ABL(IS) >10%) on imatinib (33%) than on nilotinib (9%-11%); similarly at 6 months, 16% of patients in the imatinib arm vs 3% and 7% in the nilotinib arms had EMR failure. In all arms, EMR failure was associated with lower rates of molecular response, an increased risk of progression, and lower overall survival compared with EMR achievement. We also analyzed patient and treatment characteristics associated with EMR and found distinct patterns in the nilotinib arms vs the imatinib arm. High Sokal risk score was associated with a high rate of EMR failure on imatinib, but not on nilotinib. In contrast, reduced dose intensity and dose interruptions were strongly associated with EMR failure in nilotinib-treated, but not imatinib-treated, patients. This study is registered at www.clinicaltrials.gov as #NCT00471497.

Long-Term Outcomes of Imatinib Treatment for Chronic Myeloid Leukemia

Background Imatinib, a selective BCR‐ABL1 kinase inhibitor, improved the prognosis for patients with chronic myeloid leukemia (CML). We conducted efficacy and safety analyses on the basis of more than 10 years of follow‐up in patients with CML who were treated with imatinib as initial therapy. Methods In this open‐label, multicenter trial with crossover design, we randomly assigned patients with newly diagnosed CML in the chronic phase to receive either imatinib or interferon alfa plus cytarabine. Long‐term analyses included overall survival, response to treatment, and serious adverse events. Results The median follow‐up was 10.9 years. Given the high rate of crossover among patients who had been randomly assigned to receive interferon alfa plus cytarabine (65.6%) and the short duration of therapy before crossover in these patients (median, 0.8 years), the current analyses focused on patients who had been randomly assigned to receive imatinib. Among the patients in the imatinib group, the estimated overall survival rate at 10 years was 83.3%. Approximately half the patients (48.3%) who had been randomly assigned to imatinib completed study treatment with imatinib, and 82.8% had a complete cytogenetic response. Serious adverse events that were considered by the investigators to be related to imatinib were uncommon and most frequently occurred during the first year of treatment. Conclusions Almost 11 years of follow‐up showed that the efficacy of imatinib persisted over time and that long‐term administration of imatinib was not associated with unacceptable cumulative or late toxic effects. (Funded by Novartis Pharmaceuticals; IRIS ClinicalTrials.gov numbers, NCT00006343 and NCT00333840.)

Phase 3 study of nilotinib vs imatinib in Chinese patients with newly diagnosed chronic myeloid leukemia in chronic phase: ENESTchina

Treatment with a tyrosine kinase inhibitor (TKI) targeting BCR-ABL1 is currently the standard of care for patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP). In this study, we present results of the ENESTchina (Evaluating Nilotinib Efficacy and Safety in Clinical Trials-China) that was conducted to investigate nilotinib 300 mg twice daily vs imatinib 400 mg once daily in a Chinese population. ENESTchina met its primary end point with a statistically significant higher rate of major molecular response (MMR; BCR-ABL1 ≤0.1% on the International Scale) at 12 months in the nilotinib arm vs the imatinib arm (52.2% vs 27.8%; P < .0001), and MMR rates remained higher with nilotinib vs imatinib throughout the follow-up period. Rates of complete cytogenetic response (0% Philadelphia chromosome-positive [Ph+] metaphases by standard cytogenetics) were comparable and ≥80% by 24 months in both arms. The estimated rate of freedom from progression to accelerated phase/blast crisis at 24 months was 95.4% in each arm. The safety profiles of both drugs were similar to those from previous studies. In conclusion, rates of MMR at 12 months were superior with nilotinib vs imatinib in Chinese patients with newly diagnosed Ph+ CML-CP. This trial was registered at www.clinicaltrials.gov as #NCT01275196.

Safety and efficacy of switching to nilotinib 400 mg twice daily for patients with chronic myeloid leukemia in chronic phase with suboptimal response or failure on front-line imatinib or nilotinib 300 mg twice daily

In a randomized, phase III trial of nilotinib versus imatinib in patients with newly diagnosed Philadelphia chromosome positive chronic myeloid leukemia in chronic phase, more patients had suboptimal response or treatment failure on front-line imatinib than on nilotinib. Patients with suboptimal response/treatment failure on imatinib 400 mg once or twice daily or nilotinib 300 mg twice daily could enter an extension study to receive nilotinib 400 mg twice daily. After a 19-month median follow up, the safety profile of nilotinib 400 mg twice daily in patients switching from imatinib (n=35) was consistent with previous reports, and few new adverse events occurred in patients escalating from nilotinib 300 mg twice daily (n=19). Of patients previously treated with imatinib or nilotinib 300 mg twice daily, respectively, 15 of 26 (58%) and 2 of 6 (33%) without complete cytogenetic response at extension study entry, and 11 of 34 (32%) and 7 of 18 (39%) without major molecular response at extension study entry, achieved these responses at any time on nilotinib 400 mg twice daily. Estimated 18-month rates of freedom from progression and overall survival after entering the extension study were lower for patients switched from imatinib (85% and 87%, respectively) versus nilotinib 300 mg twice daily (95% and 94%, respectively). Nilotinib dose escalation was generally well tolerated and improved responses in about one-third of patients with suboptimal response/treatment failure. Switch to nilotinib improved responses in some patients with suboptimal response/treatment failure on imatinib, but many did not achieve complete cytogenetic response (clinicaltrials.gov identifiers:00718263, 00471497 - extension).

Treatment-free remission following frontline nilotinib in patients with chronic myeloid leukemia in chronic phase: results from the ENESTfreedom study

The single-arm, phase 2 ENESTfreedom trial assessed the potential for treatment-free remission (TFR; i.e., the ability to maintain a molecular response after stopping therapy) following frontline nilotinib treatment. Patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase with MR4.5 (BCR-ABL1⩽0.0032% on the International Scale (BCR-ABL1IS)) and ⩾2 years of frontline nilotinib therapy were enrolled. Patients with sustained deep molecular response during the 1-year nilotinib consolidation phase were eligible to stop treatment and enter the TFR phase. Patients with loss of major molecular response (MMR; BCR-ABL1IS⩽0.1%) during the TFR phase reinitiated nilotinib. In total, 215 patients entered the consolidation phase, of whom 190 entered the TFR phase. The median duration of nilotinib before stopping treatment was 43.5 months. At 48 weeks after stopping nilotinib, 98 patients (51.6%; 95% confidence interval, 44.2–58.9%) remained in MMR or better (primary end point). Of the 86 patients who restarted nilotinib in the treatment reinitiation phase after loss of MMR, 98.8% and 88.4%, respectively, regained MMR and MR4.5 by the data cutoff date. Consistent with prior reports of imatinib-treated patients, musculoskeletal pain-related events were reported in 24.7% of patients in the TFR phase (consolidation phase, 16.3%).

Relative Bioavailability and Food Effect Evaluation for 2 Tablet Formulations of Asciminib in a 2‐Arm, Crossover, Randomized, Open‐Label Study in Healthy Volunteers

Asciminib (ABL001) is an orally administered allosteric inhibitor of the BCR‐ABL tyrosine kinase. The current study evaluated the relative bioavailability of its 2 tablet variants, AAA and NXA, compared with the capsule CSF and assessed the impact of food in healthy participants in a 2‐arm, randomized, open‐label, 4‐way crossover design. The primary pharmacokinetic parameters analyzed were area under the plasma concentration‐time curve (AUC) from time 0 to the time of last measurable concentration (AUClast), AUC from time 0 to infinity (AUCinf), and peak concentration (Cmax). Forty‐five healthy volunteers were enrolled, 22 in the AAA arm and 23 in the NXA arm. Under fasting conditions, the AUCinf, AUClast, and Cmax of the AAA tablet were similar to those of the capsule, but slightly higher (∼20%) for NXA and decreased with a high‐fat meal (∼65%) and a low‐fat meal (∼30%) for both tablet formulations. Overall, 20 participants (9 in the AAA arm; 11 in the NXA arm) experienced at least 1 adverse event, the most common in both arms being headache. The study showed that under fasting conditions, tablet AAA had bioavailability similar to that in the capsule CSF. The bioavailability of both tablet formulations decreased with food, with a more pronounced effect observed with a high‐fat meal.