Contributions
Abstract: PB1527
Type: Publication Only
Session title: Chronic myeloid leukemia - Clinical
Background
The therapeutic aim of chronic myeloid leukemia (CML) has profoundly changed over this decade from obtaining normal life expectancy to discontinuing medication for treatment-free remission (TFR). TKI discontinuation becomes an option for patients who achieve a stable and prolonged deep molecular response.
Aims
We report the experience of discontinuation of TKI in CML in South of Tunisia.
Methods
Our study was prospective. We included patients with CML followed at hematologic department in the south of Tunisia from October 2015 to December 2020. The criteria of inclusion suitable patients for discontinuation of TKI therapy were an age ≥18 years, a chronic phase CML with no prior history of accelerated or blast phase CML, non-high sokal-score at diagnosis, typical b2a2- or b3a2-bcr–abl1 transcripts, TKI therapy for at least 5 years, no history of resistant or progressive disease and stable deep molecular response (DMR) (bcr-abl1 ≤0.0032% IS) for at least 2 years. After TKI discontinuation, hematological monitoring including a complete blood count and bcr-abl1 messenger RNA quantification by RT-PCR were done monthly during the first 6 months, every 2 months from 7 to 12 months, quarterly the second year and then every 3 to 6 months. Molecular relapse after TKI discontinuation was defined by loss of major molecular response (MMR) (bcr-abl1 >0.1% IS) and was an indicator for a resumption of TKI.
Results
Eleven patients out of 160 patients with CML (7%) were enrolled in our study. Seven patients were women and 4 were men. Median age at TKI discontinuation was 52 years (range 48-77 years). Sokal-score at diagnosis was low in 8 cases and intermediate in 3 cases. All patients were treated with Imatinib. Median period of TKI therapy was 117 months (range 60- 180 months). The average of length of DMR before TKI discontinuation was 45 months (range 24-72 months). The median period of follow-up after TKI discontinuation was 26 months (15-50 months). Molecular relapse occurred in 4 patients (36% of patients) in the first 3 months of discontinuation therapy. After the reintroduction of TKI, all of these patients obtained DMR again with 3.2 months (3 patients at 3 months and 1 at 4 months). The remaining 7 patients (63%) achieved a TFR.
Conclusion
In our study, the rate of TFR is 63% which is similar to literature results (40-60%). We conclude that TKI can be safely discontinued in our CML population fulfilling criteria of eligibility. To make more concrete conclusion, we must enlarge patient population and much longer follow up are needed.
Keyword(s): Tyrosine kinase
Abstract: PB1527
Type: Publication Only
Session title: Chronic myeloid leukemia - Clinical
Background
The therapeutic aim of chronic myeloid leukemia (CML) has profoundly changed over this decade from obtaining normal life expectancy to discontinuing medication for treatment-free remission (TFR). TKI discontinuation becomes an option for patients who achieve a stable and prolonged deep molecular response.
Aims
We report the experience of discontinuation of TKI in CML in South of Tunisia.
Methods
Our study was prospective. We included patients with CML followed at hematologic department in the south of Tunisia from October 2015 to December 2020. The criteria of inclusion suitable patients for discontinuation of TKI therapy were an age ≥18 years, a chronic phase CML with no prior history of accelerated or blast phase CML, non-high sokal-score at diagnosis, typical b2a2- or b3a2-bcr–abl1 transcripts, TKI therapy for at least 5 years, no history of resistant or progressive disease and stable deep molecular response (DMR) (bcr-abl1 ≤0.0032% IS) for at least 2 years. After TKI discontinuation, hematological monitoring including a complete blood count and bcr-abl1 messenger RNA quantification by RT-PCR were done monthly during the first 6 months, every 2 months from 7 to 12 months, quarterly the second year and then every 3 to 6 months. Molecular relapse after TKI discontinuation was defined by loss of major molecular response (MMR) (bcr-abl1 >0.1% IS) and was an indicator for a resumption of TKI.
Results
Eleven patients out of 160 patients with CML (7%) were enrolled in our study. Seven patients were women and 4 were men. Median age at TKI discontinuation was 52 years (range 48-77 years). Sokal-score at diagnosis was low in 8 cases and intermediate in 3 cases. All patients were treated with Imatinib. Median period of TKI therapy was 117 months (range 60- 180 months). The average of length of DMR before TKI discontinuation was 45 months (range 24-72 months). The median period of follow-up after TKI discontinuation was 26 months (15-50 months). Molecular relapse occurred in 4 patients (36% of patients) in the first 3 months of discontinuation therapy. After the reintroduction of TKI, all of these patients obtained DMR again with 3.2 months (3 patients at 3 months and 1 at 4 months). The remaining 7 patients (63%) achieved a TFR.
Conclusion
In our study, the rate of TFR is 63% which is similar to literature results (40-60%). We conclude that TKI can be safely discontinued in our CML population fulfilling criteria of eligibility. To make more concrete conclusion, we must enlarge patient population and much longer follow up are needed.
Keyword(s): Tyrosine kinase