Novartis announced at the 58th American Society of Hematology (ASH) Annual Meeting & Exposition new data from the Tasigna® (nilotinib) ENESTop Treatment-free Remission (TFR) study, which demonstrate that TFR rates are consistent among Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) patients who switched from Glivec® (imatinib) due to intolerance, resistance or physician preference. ENESTop evaluated stopping Tasigna treatment in eligible Ph+ CML adults with chronic phase disease after they achieved and sustained deep molecular response (MR) for at least one year with Tasigna but had not achieved and sustained this response previously with Glivec. Results of this post-hoc analysis were presented today in an oral session (ASH Abstract #792).
“Findings from this post-hoc analysis of ENESTop suggest that the reason for switching from Glivec to Tasigna did not impact a patient’s chance of maintaining TFR,” said Timothy P. Hughes, MD, ENESTop study investigator, Cancer Theme Leader at the South Australian Health and Medical Research Institute and Clinical Professor at the University of Adelaide, Australia. “CML is considered a chronic disease due to the success of tyrosine kinase inhibitors (TKIs), but there remains a need for continued advancements and these findings are an exciting and important contribution to clinical research in CML treatment.”
This new post-hoc analysis of ENESTop evaluated rates of TFR at 48 weeks after stopping treatment with Tasigna among subgroups of patients who switched from Glivec due to intolerance, resistance or physician preference. The analysis, which included 125 patients, found that more than 50% of patients in each of the subgroups maintained TFR at 48 weeks and that the proportion of patients who maintained TFR at 48 weeks was similar across the three subgroups: 30 of 51 (58.8%; 95% confidence interval [CI], 44.2%-72.4%) in the intolerance subgroup, 16 of 30 (53.3%; 95% CI, 34.3%-71.7%) in the resistance subgroup, and 27 of 44 (61.4%; 95% CI, 45.5%-75.6%) in the physician preference subgroup. One patient who stopped treatment in the ENESTop trial was found to have had atypical transcripts and was excluded from this analysis.
ENESTop is part of a larger Tasigna TFR clinical trial program to evaluate the potential to maintain molecular response after stopping therapy in adult patients with Ph+ CML in the chronic phase who achieved a sustained deep level of molecular response with Tasigna. In the primary analysis of ENESTop, nearly 6 out of 10 (57.9%) patients (95% CI, 48.8%-66.7%) who achieved a sustained deep molecular response following at least three years of Tasigna therapy maintained a molecular response 48 weeks after stopping treatment. No new major safety findings were observed in ENESTop in patients treated with Tasigna beyond those in the known safety profile of Tasigna. The rates of all grade musculoskeletal pain were 42.1% in the first year of the TFR phase versus 14.3% while still taking Tasigna in the consolidation phase. No patients progressed to advanced phase/blast crisis. These results were previously presented at the American Society of Clinical Oncology (ASCO) Annual Meeting and the Annual Congress of European Hematology Association (EHA) in June 2016.Results from additional studies in the Tasigna TFR clinical trial program were also presented at ASH in poster sessions, including ENESTpath (Abstract #3094) and ENESTfreedom.
“Our mission at Novartis is to help transform cancer therapy through bold science and innovation, and there is no better example of this than our support of eight TFR studies in patients with CML,” said Bruno Strigini, CEO of Novartis Oncology. “Our further exploration of results from the ENESTop trial, beyond the primary analysis, reinforces our ongoing commitment to CML patients and contributes to the growing body of science that goes into treating this cancer.”
Regular and frequent molecular monitoring with a well-validated assay able to measure BCR-ABL transcript levels down to MR4.5 is an important part of Tasigna TFR studies. Frequent patient monitoring during TFR allows timely determination of loss of MR4.0 or major molecular response (MMR) and the need for treatment initiation.
Stopping CML treatment is currently not a clinical recommendation and should only be attempted in the context of a clinical study. Discontinuation of treatment in ENESTop was conducted under the conditions of the trial and in patients who met the rigorous predefined criteria of the trial.