Loss Of Cytogenetic Response Research Articles

Treatment- Free Remission in Chronic Myeloid Leukemia -Experience of a Single Brazilian Private Institution Using Imatinib Copies

Introduction: In addition to the best possible overall survival, discontinuation of the tyrosine kinase -inhibitor (TKI) treatment [treatment free response (TFR)] without observing a recurrence of the disease has become a standard part of chronic myeloid leukemia (CML) care. Evidence of several studies suggest that patients who have achieved a sustained stable deep molecular response (DMR) as MR4 and MR4.5 can be safely discontinued with close monitoring without relapse, despite BCR/ABL1 DNA remaining detectable. In Brazil, CML patients have received almost exclusively Imatinib as first-line treatment and since 2013, only generics and copies of imatinib mesylate have been used in first-line throughout the whole Public Health System and in several institutions within the private system. However, in both scenarios there is a limit coverage of PCR exams/ year which allows for adequate monitoring but it is not sufficient for the implementation of TFR safely in eligible patients Aims: To report a Brazilian single institution Imatinib discontinuation trial and to evaluate factors impacting treatment -free response (TFR) and treatment free survival (TFS) Methods: From 2020 -2021 , 26 eligible patients were invited to participate in a single arm trial of Imatinib discontinuation (DIP). Inclusion criteria: age > 18 years, chronic phase, minimum of 04 years of Imatinib therapy, deep molecular response sustained > or = 02 years (confirmed by 04 tests in the last two years, defined MR4.0 or MR 4.5 and a confirmatory exam at the moment of the screening). Atypical transcripts were excluded. After discontinuation, patients were monitored by RT- PCR monthly in the first year, every two months in the second year and every three months since the third year. Criteria for Imatinib re-initiation: loss of MMR confirmed by two exams, loss of cytogenetic response, loss of hematologic response, disease progression. TFR was calculated from the date of discontinuation until first event: loss of MMR, Imatinib reintroduction, death any cause or last follow up. TFS was calculated from the date of imatinib discontinuation until reintroduction or last follow- up (censoring deaths not related to CML). The costs of exams were provided by own founds of our institution. Results: From 26 patients, 20 patients agreed to consent inform to discontinuation of imatinib. 06 patients declined despite information because their insecurity about TFR. Twelve patients (60%) presented MR4 . Median age was 52.3 years old and 13 (65%) were female. Median time diagnosis to discontinuation of imatinib 8.04(4.6-15.5) years. Twelve (60%) patients sustained TFR. Seven patients of twelve had presented MR 4 and five had MR 4.5 in the screening, respectively . (p=0,85) .It means 58,3% of the total of patients with MR 4 and 62,5% with MR 4.5 . In this interim analysis the median time of follow up was 14.5 (2.7-18.8) months. One patient died due to COVID19 with major molecular response (MMR). Eight (40%) lost MMR and imatinib was restarted. In this group the median time until MMR loss was 7.24 (2.1-13.8) months. At this moment, 07 patients (87,5 %) recovered MMR . In addition , in this group 06 patients (75%) achieved the same level of MR with reintroduction of imatinib with median 5.2 (3.7-6.3) months. Regarding adherence, 4 (20%) had some absences in monthly medical consultations and 1(5%) missed follow-up. Fifteen tests (6.14%) were performed to confirm MR loss, however only in 8 tests (53.3%) were confirmed. In fact, 04 patients (33,33%) still in TFR because of the double confirmatory test. There was no transformation to advanced phases. Gender, age at de diagnosis , age at discontinuation, Sokal , BCR-ABL trasncripts type , duration of Imatinib therapy , duration of MR 4.0 or MR4.5 did not affect TFR. Withdrawal syndrome occurred in 05 patients (25%) ; 04 patients with grade 1 and 01 patient with grade 2, had been used corticosteroid for few days. Conclusions: Despite the small number of patients included and short time of follow-up, the preliminary results of this trial demonstrated the feasibility and safety of Imatinib discontinuation , even using Brazilian copies, and the results were similar of that presented in another trials . The confirmatory exam to establish the loss of TFR was useful and safe. Adhesion of a discontinuation is one of the most important keys of the success of TFR.

TREATMENT- FREE REMISSION IN CHRONIC MYELOID LEUKEMIA -EXPERIENCE OF A SINGLE BRAZILIAN PRIVATE INSTITUTION USING IMATINIB COPIE

Evidence of several studies suggest that patients who have achieved a sustained stable deep molecular response (DMR) as MR4 and MR4.5 can be safely discontinued with close monitoring without relapse, despite BCR/ABL1 DNA remaining detectable. In Brazil, CML patients have received almost exclusively Imatinib as first-line treatment. However, in both scenarios there is a limit coverage of PCR exams/ year which allows for adequate monitoring but it is not sufficient for the implementation of TFR safely in eligible patients. To report a Brazilian single institution Imatinib discontinuation trial and to evaluate factors impacting treatment -free response (TFR) and treatment free survival (TFS) provided by own founds. From 2020 -2021, 26 eligible patients were invited to participate in a single arm trial of Imatinib discontinuation (DIP). Inclusion criteria: age > 18 years, chronic phase, minimum of 04 years of Imatinib therapy, deep molecular response sustained > or = 02 years (confirmed by 04 tests in the last two years, defined MR4.0 or MR 4.5 and a confirmatory exam at the moment of the screening). Atypical transcripts were excluded. After discontinuation, patients were monitored by RT- PCR monthly in the first year, every two months in the second year and every three months since the third year. Criteria for Imatinib re-initiation: loss of MMR confirmed by two exams, loss of cytogenetic response, loss of hematologic response, disease progression. TFR was calculated from the date of discontinuation until first event: loss of MMR, Imatinib reintroduction, death any cause or last follow up. TFS was calculated from the date of imatinib discontinuation until reintroduction or last follow- up (censoring deaths not related to CML). The costs of exams were provided by own founds of our institution. From 26 patients, 20 patients agreed to consent inform to discontinuation of imatinib. 06 patients declined despite information because their insecurity about TFR. Twelve patients (60%) presented MR4. Median age was 52.3 years old and 13 (65%) were female. Median time diagnosis to discontinuation of imatinib 8.04(4.6-15.5) years. Twelve (60%) patients sustained TFR. Seven patients of twelve had presented MR 4 and five had MR 4.5 in the screening, respectively. (p = 0,85). It means 58,3% of the total of patients with MR 4 and 62,5% with MR 4.5. In this interim analysis the median time of follow up was 14.5 (2.7-18.8) months. One patient died due to COVID19 with major molecular response (MMR). Eight (40%) lost MMR and imatinib was restarted. In this group the median time until MMR loss was 7.24 (2.1-13.8) months. At this moment, 07 patients (87,5 %) recovered MMR. In addition, in this group 06 patients (75%) achieved the same level of MR with reintroduction of imatinib with median 5.2 (3.7-6.3) months. Regarding adherence, 4 (20%) had some absences in monthly medical consultations and 1(5%) missed follow-up. Fifteen tests (6.14%) were performed to confirm MR loss, however only in 8 tests (53.3%) were confirmed. In fact, 04 patients (33,33%) still in TFR because of the double confirmatory test. There was no transformation to advanced phases. Gender, age at de diagnosis, age at discontinuation, Sokal, BCR-ABL trasncripts type, duration of Imatinib therapy, duration of MR 4.0 or MR4.5 did not affect TFR. Withdrawal syndrome occurred in 05 patients (25%); 04 patients with grade 1 and 01 patient with grade 2, had been used corticosteroid for few days. The preliminary results of this trial demonstrated the feasibility and safety of Imatinib discontinuation, even using Brazilian copies, and the results were similar of that presented in another trials.

Duration of Major Molecular Response and Discontinuation in Deep Molecular Response (MR4.5) Were Associated with Longer Treatment-Free Survival after Imatinib Discontinuation - Results from Two Prospective Brazilian Trials

Several trials have demonstrated the feasibility of discontinuation of tyrosine kinase inhibitors (TKI) treatment in chronic myeloid leukemia (CML) patients (pts) with deep molecular response. Aims: to report the results of two Brazilian imatinib (IM) discontinuation trials and to evaluate factors impacting in treatment-free remission (TFR) and treatment-free survival (TFS) after IM discontinuation. Methods:Between September 2016 and January 2019, 60 CML pts were included in two ongoing phase II, single arm, prospective Brazilian discontinuation trials: Pilot Study of Discontinuation in Patients With Chronic Myeloid Leukemia With Deep Molecular Response - Evaluation of Pioglitazone in Treatment-free Remission (TFR) (EDI-PIO UNICAMP)(NCT02852486)and Imatinib Discontinuation in Patients With Chronic Myeloid Leukemia Chronic Phase With Sustained MR4log(USP) (NCT03239886). Inclusion criteria: age >18 years, chronic phase, minimum of 3 years of IM therapy, deep molecular response for ≥ 2 years (confirmed by 4 tests in the last 2 years, defined as MR4.0 in USP trial and MR4.5 in EDI-PIO). Patients participating in EDI-PIO trial used pioglitazone 30 mg/day plus IM for 3 months before IM discontinuation (n=30). After discontinuation, pts were monitored by quantitative RQ-PCR monthly in the first year, every 2 months in the second year and every 3 months in the third year. Criteria for IM re-initiation: loss of MMR (in one test), loss of cytogenetic response, loss of hematologic response, disease progression or confirmed loss of MR4.0 (this criteria used only in EDI-PIO trial). TFR was calculated from the date of discontinuation until first event (loss of MMR; IM reintroduction; death any cause or last follow-up); TFS was calculated from the date of IM discontinuation until reintroduction or last follow-up (censoring deaths not related to CML). Adverse events after IM discontinuation were reported according to CTCAE. Results:Data cut-off for analysis was February 2019. In the 1stanalysis 48 pts who discontinued IM in MR4.5 were analyzed. Patient's characteristics from EDIPIO (n=30) and USP (n=18) trials were: 57% vs. 67% male, median age of 55 (29-77) and 56 (33-95) years (29-95) at discontinuation; 16% and 33% had used previously Interferon; median duration of IM treatment of 10 (3-16) vs. 10 (5-15) years; median duration of MMR 95 (30-149) vs. 93 (57-130) months; MR4.0 was 90 (26-135) vs. 89 (30-123) months; and MR4.5 was 76 (23-135) vs. 75 (30-102) months; none variable had statistical difference.One patient died in MMR due to cardiac failure. TFR was 61% (95% CI 47-75) at 20 months. Sixteen (33%) out 48 re-initiated IM (2 with confirmed loss of MR4.0 and 14 with loss of MMR) in a median time of 20 (1-26) months. All relapsed pts recovered MMR after IM reintroduction, in a median time of 2 months (0-4). There was no transformation to advanced phases. No serious adverse events were reported during pioglitazone treatment. In the Cox regression the duration of MMR was associated with a longer TFR HR: 0.96 (beta-) (CI 95%:0.94-0.99, P= 0.006). Gender, age at diagnosis, age at discontinuation, treatment with pioglitazone, Sokal and EUTOS scores, BCR-ABL transcripts type, duration of IM therapy, duration of MR4.0 and MR4.5 and previous use of Interferon did not affect TFR.In the second analysis all 60 pts were included. TFS was 56% and was higher in pts who discontinued IM in sustained MR4.5 vs. MR4.0 (63% vs. 33%, P=0.04)(Figure). The independent factors for TFR in the multivariate analysis by Cox-regression were the duration of MMR [HR: 0.97 (beta-), 95%CI: 0.95-0.98, P=0.001] and intermediate/high risk Sokal [HR 3.14 95%CI: 1.08-9.11, P= 0.035]. Twenty-four out of 60 pts (40%) re-initiated IM (2 with confirmed loss of MR4.0 and 22 with loss of MMR).Adverse events occurred in 38 (63%) pts, 30% attributed to withdrawal syndrome. Some pts presented more than one event. Grade 1-2: arthralgia or muscular pain (17), hyperglycemia (4), hypertriglyceridemia (2), polycythemia (2), hypertension (3), and others (11). Four pts had grade 3-4 event: arthralgia (1), death for cardiac failure (1), abortion and hypertriglyceridemia (1). Conclusions:both trials demonstrated the feasibility and safety of IM discontinuation in pts in sustained deep molecular response. The duration of MMR was associated with a higher TFR and TFS rate. Imatinib discontinuation was more successful in pts in stable MR4.5. Figure Disclosures Pagnano: Pint Pharma: Consultancy; Abbvie: Consultancy; Sandoz: Consultancy. Delamain:Novartis: Honoraria.

Chronic Myeloid Leukemia: Long-Term Outcome Data in the Imatinib Era.

Recent reports suggest that in the TKI era, the survival of chronic myeloid leukemia approaches that of general population. The real-world situation may be different. We analyzed patients (≥ 18years) with chronic phase (CP) CML enrolled over a 7-year period (2002-2008) in an imatinib access program. Event was defined as non-achievement/loss of complete hematological response (CHR), loss of cytogenetic response or progression to accelerated (AP)/blast phase (BC). Progression was defined as development of AP/BC. Any delay of ≥ 1week in reporting for drug refills was categorized as non-adherence. Of the 443 patients with CP-CML who started imatinib [median age: 36years (18-70); High risk: 32% (Sokal) and 14% (Hasford/EUTOS)], 162 (37%) had received prior therapy [mostly hydroxyurea (N = 153]. CHR was achieved by 430 (97%). After a median follow up of 109.5months (3.4-184.3), the EFS, PFS and OS at 10years was 43%, 75% and 76% respectively. Superior EFS was predicted by low-risk Hasford score and adherence to therapy. Adherence to therapy was the only factor which predicted EFS on multivariate analysis (HR 0.64, 95% CI 0.50-0.83, P = 0.001). Long-term follow up of patients with CP-CML reflects poorer survival than those reported from clinical trials and reflects multiple issues that affect "real-world" patients. The continued drop in EFS, noted during long-term follow up, might take time to impact the PFS and OS due to the chronic nature of the disease. Sustained adherence to therapy is important for optimum long-term outcomes.

Chronic Myeloid Leukaemia Patients with Stable Molecular Responses (at least MR3) May Safely Decrease the Dose of Their Tyrosine Kinase Inhibitor: Data from the British Destiny Study

▪Several studies have established that some chronic myeloid leukaemia (CML) patients with enduring deep molecular responses to tyrosine kinase inhibitor (TKI) therapy can discontinue treatment. However, these studies are confined to patients in stable MR4, i.e. whose BCR-ABL/ABL ratio is consistently below 0.01% (molecular response 4 logs below an arbitrary baseline). Although there are anecdotal reports of successful treatment cessation for a few months in patients in stable MR3 (i.e. BCR-ABL <0.1%; major molecular response) but not MR4, e.g. during pregnancy, such patients have not hitherto been formally studied in a stopping trial. In addition, we questioned whether some patients who experience molecular recurrence on stopping TKI might nevertheless be able to safely decrease TKI treatment without molecular recurrence.In the British De-Escalation and Stopping Therapy with Imatinib, Nilotinib or sprYcel (DESTINY) study, patients in at least stable MR3 (on the International Standard) initially decreased their TKI to half the standard dose for 12 months, followed by complete cessation. Key entry requirements included first chronic phase of CML; receiving the same TKI since original diagnosis (except that one switch was permissible if for intolerance to the initial drug); on TKI for at least 3 years; all PCR tests in the past 12 months were in at least MR3 (minimum of 3 tests, each with >10,000 ABL control transcripts). Central monitoring was carried out monthly. Molecular recurrence was defined as loss of MR3 (>0.1%) on two consecutive samples; this prompted resumption of full dose of their entry TKI.Between December 2013 and April 2015, 174 patients (male 98; female 76) were recruited after giving informed consent from 20 UK centres. At entry, 148 patients were receiving imatinib, 16 nilotinib and 10 dasatinib. After 12 months of half-dose therapy (imatinib 200mg daily, nilotinib 200mg twice daily or dasatinib 50mg daily), molecular recurrence was lower in patients with stable MR4 at entry (3 of 125 patients; 2.4%) than in those in MR3 but not MR4 (9 of 49 patients; 18.4%) (p < 0.001). The median time to relapse was shorter in the sustained MR3 group than in those in sustained MR4 at entry (4.4 months vs 8.7 months). The probability of molecular recurrence on de-escalation was not related to age, gender, performance status, prior TKI (imatinib vs second generation) or the duration of TKI therapy (median 7.0 years overall). No progression to advanced phase or loss of cytogenetic response was seen; one death and 15 serious adverse events occurred which were all unrelated to CML or TKI treatment. All 12 patients with molecular recurrence regained MR3 within 4 months of resumption of full dose TKI. During the first 3 months of de-escalation but not thereafter, the number of patient-reported common TKI side effects decreased, though interestingly 53 new musculoskeletal symptoms were reported by 36 patients (21%) which were typically mild and transient.In CML patients with stable MR3 or better, decreasing TKI treatment to half the standard dose appears safe, and is associated with improvement in TKI related side effects, implying that many patients with stable responses are being overtreated. Studies of more ambitious de-escalation are warranted. DisclosuresClark:Ariad: Honoraria; Novartis: Honoraria, Research Funding, Speakers Bureau; Bristol Myers Squibb: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria, Research Funding, Speakers Bureau. Apperley:Novartis: Honoraria, Speakers Bureau; Incyte: Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Bristol Myers Squibb: Honoraria, Speakers Bureau; Ariad: Honoraria, Speakers Bureau. Pocock:Gilead Sciences: Other: Sponsorship to attend the EHA 2016 Meeting; Janssen: Speakers Bureau; Takeda: Honoraria. Smith:Bristol Myers Squibb: Honoraria; Novartis: Honoraria; Pfizer: Honoraria; Ariad: Honoraria. Byrne:Bristol Myers Squibb: Consultancy, Speakers Bureau. O'Brien:Ariad: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding. Copland:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Honoraria; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; ARIAD: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Characterization of the Genomic Landscape of BCR-ABL1 Kinase-Independent Mechanisms of Resistance to ABL1 Tyrosine Kinase Inhibitors in Chronic Myeloid Leukemia

Despite the well-established success of ABL1 tyrosine kinase inhibitors (TKIs) in the treatment of patients with chronic myeloid leukemia (CML), approximately 20% of patients treated with frontline imatinib develop resistance by 5 years on therapy. The majority (~60%) of such resistant cases are explained by acquired mutations within the BCR-ABL1 kinase domain that compromise inhibitor binding, and nearly all of these mutations are effectively targeted by one or more of the 2nd and 3rd generation ABL1 kinase inhibitors. In contrast, the remaining ~40% of imatinib-resistant cases harbor no explanatory BCR-ABL1 kinase domain mutation, presumably attributable to BCR-ABL1 kinase-independent mechanisms. We hypothesized that resistance in these patients results from acquired auxiliary molecular aberrations which persistently activate signaling pathways downstream despite inhibition of BCR-ABL1 kinase activity. To identify such mechanisms, we performed whole exome sequencing and RNA sequencing on a cohort of 135 CML patients comprising the following subgroups: newly diagnosed/TKI naïve (n=28), BCR-ABL1 kinase-dependent resistance (n=31), and BCR-ABL1 kinase-independent resistance (n=65), and TKI-induced remission (n=7). Resistant patients were required to have demonstrated clinical resistance to one or more ABL1 kinase inhibitors in the form of suboptimal response or loss of cytogenetic response; the subtype of resistance was defined based on the presence or not of an explanatory BCR-ABL1 kinase domain mutation at the time of resistance. The majority of samples collected were from patients with chronic phase CML (n=97), although smaller cohorts of accelerated phase CML, blast crisis CML, and Ph+ ALL were also profiled (n=20, 19, and 9, respectively). Among the 44,413 protein-altering and 902 splice site variants detected across the 120 WES samples, there were on average 908 missense, 146 truncation and 69 splice variants per sample. Genes with truncation and missense variants were compared between BCR-ABL1 kinase-independent and -dependent resistant chronic phase samples. A total of 44 genes were seen with a frequency difference of at least 10%, including PLEKHG5 and NKD2 (30% and 28% difference, respectively), which are involved in regulation of NF-kB and Wnt signaling. Consistent with previous reports, we also detected EZH2 and TET2 as exclusively mutated in the BCR-ABL1 kinase-independent resistance patients (6% and 3%, respectively). Further analyses stratifying variants among resistant patients according to specific ABL1 kinase inhibitor therapy failed and comparing, where available, serial samples from pre- and post-treatment for clonal expansion are underway. Additionally, sufficient material was available to perform ex vivo small-molecule inhibitor screening for 48 patient specimens, the resultant data of which was used to generate putative effective drug target profiles and integrated with exome sequencing variants to prioritize variants of functional relevance (HitWalker; Bottomly et al., Bioinformatics 2013). Among 23 patient samples exhibiting BCR-ABL1 kinase-independent resistance, the mutated genes most frequently ranked in the top 10 functional-prioritized variants were: ABL1 (which included non-kinase domain variants; 34.7%), MAP3K1, MUC4, FGF20 (each 17.4%), ARHGEF15, MEF2A, EPHA8, TYRO3, BMP2K, and IRS1 (each 13.0%). Notably, the top six candidates are members of the neutrophin (ABL1, MAP3K1, and IRS1), EPHA forward (EPHA8, ARHGEF15), and p38 MAPK signaling pathways (MAP3K1 and MEF2A). Taken together, these findings suggest that several of the same pathogenic molecular abnormalities seen in other myeloid malignancies are also present in CML patients with BCR-ABL1 kinase-independent resistance, including a subset which align to persistent re-activation of signaling pathways involved in CML disease pathogenesis and progression. As such, genetic and/or functional profiling of these patients in the clinic may translate to actionable candidates for combination therapy to maximize disease control and improve patient outcomes. DisclosuresAgarwal:CTI BioPharma Corp: Research Funding. Radich:Novartis: Consultancy, Research Funding; BMS: Consultancy; Ariad: Consultancy. Deininger:Novartis: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Incyte: Consultancy, Membership on an entity’s Board of Directors or advisory committees; Gilead: Research Funding; CTI BioPharma Corp.: Membership on an entity’s Board of Directors or advisory committees; Celgene: Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Ariad: Consultancy, Membership on an entity’s Board of Directors or advisory committees. Druker:Pfizer: Patents & Royalties; Dana-Farber Cancer Institute: Patents & Royalties: Millipore royalties via Dana-Farber Cancer Institute; Curis: Patents & Royalties; Array: Patents & Royalties; CTI: Consultancy, Equity Ownership; Pfizer: Patents & Royalties; Curis: Patents & Royalties; Array: Patents & Royalties; Dana-Farber Cancer Institute: Patents & Royalties: Millipore royalties via Dana-Farber Cancer Institute; Oncotide Pharmaceuticals: Research Funding; Novartis: Research Funding; BMS: Research Funding; ARIAD: Patents & Royalties: inventor royalties paid by Oregon Health & Science University for licenses, Research Funding; Roche: Consultancy; Gilead Sciences: Consultancy, Other: travel, accommodations, expenses; D3 Oncology Solutions: Consultancy; AstraZeneca: Consultancy; Ambit BioSciences: Consultancy; Agios: Honoraria; MolecularMD: Consultancy, Equity Ownership, Patents & Royalties; Lorus: Consultancy, Equity Ownership; Cylene: Consultancy, Equity Ownership.

Differential Expression of BIRC Family Genes In The Course Of Chronic Myeloid Leukemia – BIRC3 and BIRC8 As Potential New Candidates To Identify Disease Progression

Although majority of chronic myeloid leukemia (CML) patients benefit from targeted therapy, there is an unmet need to identify as early as possible patients who develop resistance to tyrosine kinase inhibitors (TKI) and/or patients who progress to blastic phase (CML-BP). Searching for potential candidates of disease progression we have focused on BIRC (baculoviral IAP repeat-containing) genes expression in various stages of CML. This family includes eight functionally- and structurally-related proteins, most of them are believed to serve as endogenous inhibitors of apoptosis. Overexpression of various BIRC genes has been associated with cancer progression, multidrug resistance, poor prognosis and short survival in several types of neoplasms including hematological malignancies. In CML so far expression of BIRC5 (encoding survivin) and BIRC4 (encoding XIAP) has been associated with progression of the disease. However, there is no data on the role of other BIRC members in myeloproliferative diseases.To study the expression of BIRC genes in CML we employed RT-qPCR following MIQE guidelines. We analyzed sequential samples of peripheral blood leukocytes obtained from CML patients at various stages of the disease. Initially we looked at the samples from patients in chronic phase (CML-CP): at the diagnosis and after development of TKI resistance (confirmed as a loss of cytogenetic response, n=5). Then we analyzed samples from patients who progressed either to accelerated phase (CML-AccPh) or to blastic phase (CML-BP) (n=6). Among eight BIRC genes we observed significant decrease in BIRC3 (encoding cIAP2) and BIRC8 (encoding ILP2) expression. This was associated both with TKI resistance and with progression of CML to accelerated or blastic phase. Simultaneously, we observed marked increase in BIRC5 expression in samples from CML-AccPh and BP as compared to chronic phase (as was previously shown by others) but we observed no significant difference in BIRC5 expression between CML-CP diagnostic and TKI-resistant samples. Expression of BIRC1 (NAIP), BIRC2 (cIAP1), BIRC4 (XIAP), BIRC6 (BRUCE) and BIRC7 (LIVIN) was comparable in sequential samples from CML-CP and CML-BC and was not related to TKI-resistance.We verified these results by comparing larger group of patients in either CML-CP at the diagnosis prior to any treatment (n=15) or CML-BP (n=11). To compare the expression of BIRC family in CML to normal hematopoietic cells, we included also cDNA from healthy blood donors (n=10). In accordance with paired samples analysis, we observed downregulation of BIRC3 and BIRC8 expression in CML-BP (as compared to CML-CP and healthy blood donors), while BIRC5 was upregulated in CML-BP patients (as compared to CML-CP and healthy blood donors). There was no difference in expression of other BIRC family members.In conclusion, this is the first comprehensive analysis of the expression of all eight BIRC genes in the course of CML. In addition to the previously described upregulation of BIRC5, we observed significant downregulation of BIRC3 and BIRC8 associated with TKI-resistance and also with progression to accelerated or blastic phase. Recently Rossi D. et al. (Blood 2012;119: 2854-62) described potential role of disruption of BIRC3 (through mutation or gene deletion) in resistance to fludarabine in chronic lymphocytic leukemia. Together with our results this shows that current view linking BIRC genes upregulation with tumor progression and drug resistance may not be true for all of BIRC genes. Our results suggest novel and unexpected role of BIRC3 and BIRC8 in the clonal evolution of CML and open a new area for further exploration of the role of BIRC in CML progression. Disclosures:No relevant conflicts of interest to declare.

Outcomes of Chronic Phase (CP) Chronic Myeloid Leukemia (CML) Patients (pts) After Surviving 5 Years of Initial Therapy with Interferon Alpha (IFN), Imatinib (IMA) or Allogeneic Stem Cell Transplantation (ASCT)

Abstract 2001▪▪This icon denotes a clinically relevant abstract Introduction:IFN and ASCT were the most commonly used treatment modalities for CML before 2001. The introduction of IMA as the preferred treatment for CML changed the treatment paradigms for this disease. CML pts are now expected to live longer and responses are prolonged in most cases. However, long-term outcomes including late relapses, durability of response, side effects, and late development of new medical conditions are largely unknown. Methods:We performed a chart review of pts with CML in CP treated at our institution who have survived at least 5 yrs of their initial IFN or IMA therapy, or 5 yrs after ASCT, to analyze their long-term outcome, risk of late relapse, and emergence of late side effects or new medical health problems. Results:469 pts with CML CP treated at our institution between 1981 and 2006 survived at least 5 yrs on their initial CML treatment. One hundred twenty five pts are described in this analysis: 25 pts in the IFN group, 50 pts in the IMA group (400 mg/d), and 50 pts in the ASCT group. Pts received their initial treatment a median of 1 month (range, 0.3 to 11), 1 month (range, 0 to 7), and 13 months (range, 1 to 126) from diagnosis, respectively. Median time on initial therapy for the IFN and IMA groups was 6.4 yrs (range, 5–8.5) and 10.8 yrs (range, 5.1–11.5). Characteristics of the pts at time of diagnosis were as follows: hypertension (HTN) was present in 12%, 30% and 2% of the IFN, IMA, and ASCT pts, respectively; cardiac disease in 12%, 8% and 2%, respectively; thyroid disease (Thy) in 8%, 8% and 2%, respectively. Median number of medications (MEDS) per patient at baseline was 1 (range, 0–5), 1 (range, 0–13) and 0 (range, 0–4), respectively. Complete cytogenetic response (CCyR) was obtained in 76% (n=19), 96% (n=48) and 100% (n=50) of the pts, respectively. Time to best CyR was 17.1 months (mos) (range, 6–59.1), 7.2 mos (range, 2.4–64.2) in the IFN and IMA groups, respectively. Loss of cytogenetic response after 5 years occurred in 91% (n=21, 2 pts had no initial response, 2 pts remained in CCyR), 10% (n=5) and 6% (n=3), respectively. Twenty pts (80%) on the IFN cohort were switched to IMA at a median of 7.4 yrs (range, 5.3–13.3) after diagnosis (19 occurring between yrs 2000 and 2001). Of these 20 pts 75% (n=15) achieved MMR or better after a median of 4 yrs (range, 0.6–10.2) on IMA. New medical problems that developed at the 5 year mark were a follows: Thyroid problems in 8%, 0% and 10%, respectively, HTN in 0%, 2% and 14%, respectively; cardiac in 0%, 4% and 0%, respectively; and other in 44%, 22%and 58%, respectively. Median MEDS per patient at the 5 year mark was 2 (range, 0–7), 4 (range, 1–12) and 2 (range, 0–15), respectively. New medical problems that developed by last follow up were a follows: Thyroid problems in 4%, 6% and 0%, respectively; HTN in 4%, 18% and 10%, respectively, cardiac in 8%, 4% and 4%, respectively; osteoporosis in 0%, 0% and 6%, respectively, and other in 44%, 32% and 26%, respectively. Median Meds per patient at last follow up was 4 (range, 0–19), 6 (range, 1–16) and 2 (range, 0–25), respectively. Secondary malignancies occurred in 8%, 10% and 12% of patients, respectively. Pts continued to be on initial treatment in 16% (n=4), 94% (n=47) and 94% (n=47), respectively. At date of last follow up, late relapses (beyond 5 yrs of initial therapy) occurred in 72% (n=18), 8% (n=4) and 2% (n=1), respectively. At median follow up of 18, 11, and 14 yrs respectively, 76% (n=19), 92% (n=46) and 92% (n=46) are alive, 64% (n=16), 86% (n=43) and 90% (n=45) in CCyR. Conclusion:CP CML pts treated with IMA or SCT and surviving 5 yrs beyond initial treatment have low incidence of late relapses. New medical problems including heart disease and secondary malignancies may occur in some pts, but most pts are still alive. Pts with CML require prolonged medical care even in the setting of lasting remissions. Disclosures:Jabbour:BMS: Honoraria; Pfizer: Honoraria, Research Funding; novartis: Honoraria. Cortes:Novartis: Consultancy, Research Funding; Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; BMS: Consultancy, Research Funding.

Comparison of Adherence Between Nilotinib and Dasatinib As Second-Line Therapies in Chronic Myeloid Leukemia

Abstract 2754 Background:According to the NCCN guidelines, the recommended treatment option for patients diagnosed with Philadelphia-positive (Ph+) chronic myeloid leukemia (CML) in chronic or accelerated phases who are resistant or develop intolerance to first-line imatinib is to switch to one of the two second-generation BCR-ABL tyrosine kinase inhibitors, nilotinib or dasatinib. There is limited information on their comparative adherence. Analysis of adherence may reveal whether these two drugs are being used as intended and how adherence issues may potentially affect clinical outcomes. Nonadherence to imatinib has been associated with loss of cytogenetic response, imatinib failure, and higher rates of inpatient visits. A prior study covering the period up to 6/2009 has revealed a better adherence profile for nilotinib versus dasatinib. Since dasatinib was approved for once daily use in addition to twice daily use in 05/2009, this study replicated the analysis using more recent data to compare adherence between nilotinib and dasatinib as second-line therapies in CML. Methods:Medical and pharmacy records from two databases from January 1997 to April 2010 were combined to identify adult patients diagnosed with CML (ICD-9 code 205.1x) with ≥1 prescription for either nilotinib or dasatinib. Patients were required to have continuous enrollment ≥1 month prior to and after the index date, defined as the first prescription for nilotinib or dasatinib, and to continue their treatment ≥1 month before discontinuing or switching to another TKI. Adherence over an up-to 180-day period was evaluated based on the proportion of days covered (PDC; sum of days of medication on hand for nilotinib or dasatinib divided by the number of calendar days in the study period). Medication possession ratio (MPR) was also evaluated in a sensitivity analysis. PDC and MPR were compared between cohorts using linear regression models. Discontinuation was defined as a treatment gap ≥30 days, and rates were compared between cohorts using Kaplan-Meier survival analyses and Cox proportional hazard regression models. In a sensitivity analysis, discontinuation was defined as a treatment gap ≥90 days. All multivariate regression models were controlled for age, gender, CML complexity, adverse events at baseline, number of inpatient days, emergency room (ER) visits and outpatient visits during baseline, medical costs during baseline, CML year of diagnosis, Charlson Comorbidity Index, and bone marrow or stem cell transplant before the index date. Results:Adherence and discontinuation were analyzed for a total of 558 CML patients receiving a second-line TKI (473 dasatinib and 85 nilotinib). Patient characteristics were generally similar. Patients in the dasatinib cohort had a longer mean follow-up period compared with those in the nilotinib cohort (162 days vs. 146 days; P = 0.0007) and greater utilization and costs associated with inpatient and ER services. The mean PDC over the study period for nilotinib was higher compared with dasatinib (0.81 vs 0.68). After adjusting for confounding factors, the nilotinib group had a 0.115 higher PDC (approximately 17% higher) compared to the dasatinib group (P = 0.0004). Additionally, patients in the nilotinib group had a significantly higher MPR compared to patients in the dasatinib group (0.90 vs. 0.77 P = 0.0043). Discontinuation rates (gap ≥30 days) were significantly higher for dasatinib users than for nilotinib users, with an adjusted hazard ratio of 2.15 (P = 0.0013). Dasatinib-treated patients had higher discontinuation rates than nilotinib-treated patients after 3 months (40% vs 22%) and 6 months (50% vs 28%). These unadjusted differences were robust in the sensitivity analysis with discontinuation defined as a treatment gap ≥90 days, but the difference between the cohorts was no longer significant after adjusting for confounding factors (HR 1.76, P = 0.1328). Conclusions:This retrospective study showed that CML patients treated with nilotinib for second-line treatment were significantly more adherent to therapy, based on PDC and MPR, and had a lower discontinuation rate than did patients receiving dasatinib in this analysis. Further studies are needed to better understand treatment-specific factors affecting adherence and persistence (e.g., treatment cost, tolerability profile, dosing convenience). Disclosures:Guerin:Novartis Pharmaceutical Corporation: Annie Guerin is an employee of Analysis Group, Inc, which has received research funds from Novartis Pharmaceuticals. Bollu:Novartis Pharmaceutical Corporation: Employment, Vamsi K. Bollu worked for the Novartis Pharmaceuticals Corporation while performing this analysis but is currently employed by Sunovion Pharmaceuticals Inc. Sunovion Pharmaceuticals Inc. was not in any way associated with this study. Guo:Novartis Pharmaceutical Corporation: Employment. Stepner:Novartis Pharmaceutical Corporation: Michael Stepner is an employee of Analysis Group, Inc, which has received research funds from Novartis Pharmaceuticals. Griffin:Novartis Pharmaceutical Corporation: James D. Griffin is an employee of the Dana Farber Institute which has received consultancy fees from Analysis Group, Inc, which has received research funds from Novartis Pharmaceuticals Corporation. Wu:Novartis Pharmaceutical Corporation: Eric Q. Wu is an employee of Analysis Group, Inc, which has received consultancy funds from Novartis Pharmaceutical Corporation.

Imatinib Resistance Mutation Analysis Pattern In Chronic Myeloid Leukemia (CML) Patients on Imatinib In Indian Population.

AbstractAbstract 4491 Background-Imatinib has revolutionized the treatment of CML. Still there are hurdles with the drug, as, with the passage of time patients are either not responding or showing loss of response. The nonresponsiveness has been proved to be due to genetic mutations which may be primary or acquired. Still less is known about the pattern of mutations especially in asian countries. So there is a need to identify the pattern of mutations, so that second line tyrosine kinase inhibitors' response may be studied with respect to these mutations and new drugs can be designed concentrating on the most common mutations. In an attempt to identify a pattern of mutation in asian population we carried out an analysis at our centre. Methods-The patients who were on imatinib at Kidwai memorial institute of oncology, underwent testing for hematological response(HR) every month, cytogenetic response (CyR) every 6 month and molecular response(MR) every year. Patients who did not achieve either hematologic or cytogenetic or molecular milestones or had loss of response underwent imatinib resistance mutation analysis(IRMA). We analyzed a total of 102 patients. The IRMA was done at Oncquest Laboratories Ltd.,New Delhi, India. The method used at the laboratory is a combination of RTPCR and double pass sequencing. The sequence results were analyzed using BLAST software from NCBI and GRAPH ANALYSIS software from applied biosystems. Results-Between Jan. 2007 to May 2010, a total of 102 patients were analysed for imatinib resistance. Out of these 102 patients, 5(4.9 %) patients presented in blast crisis, 7(6.86%) in accelerated phase and 90(88.23%) in chronic phase. Male to female ratio was 1.7:1. 95 patients had achieved complete hematological response(CHR) at the end of 3 mths but 7 patients did not achieve CHR at 3 mths. So these were the candidates of IRMA. 2 patient had loss of HR. 42 patients did not achieve cytogenetic milestones. 28 patients had loss of cytogenetic response. 15 patients did not achieve major molecular response. and 8 had loss of molecular response. So these 102 patients were candidates for IRMA. Analysis revealed: No mutation - 74 patients. F 359 I – 3 patients, T 315 I(Thr to Ile) – 4 patients, M 351 T (Met to Thr) – 5 patients, M 244 V (Met to Val) – 2patients, H 395 R – 1 patients, Y 253 H – 2 patients, 355 G(GLU to GLY) – 1 patient, 250 E (GLY to GLU)- 1 patient, G250 E (GLY to GLY) - 1patient, F 359 C (Phe to Cys) – 1 patient, F 311 L(Phe to Leu) – 1 patient, Y 253 F(Tyr to Phe) – 1 patient, E 275 K (Glu to Lys) – 2 patients, V 253 F – 2 patients and F317L- 1 patient. Conclusions-Most of the patients (74/102 patients) did not show any mutations. Most common mutation seen was M 351 T in 5 patients. T 315 I mutation was seen in 4 patients and all these patients had a loss of response. All these mutations should be studied with respect to response to second line tyrosine kinase inhibitors particularly in asian Indian population. Disclosures:No relevant conflicts of interest to declare.

The Use of 2nd generation Tyrosine Kinase Inhibitors (TKI) after Failure to 2 Prior TKI: Long-Term Follow-up.

The 2nd generation tyrosine kinase inhibitors (TKI), nilotinib and dasatinib, are effective after imatinib failure. These agents are now also being used as 3rd line therapy after failure to 2 prior TKI. Preliminary data suggests responses can be achieved with this strategy, but the long-term benefit is unknown.To investigate the long-term benefit of using a 2nd generation TKI after having failed imatinib and another TKI.Patients with CML who were sequentially treated with 3 different TKI's at M.D. Anderson Cancer Center were reviewed. Response to the 3rd TKI were scored according to standard definitions. Event-free survival (EFS) was considered from the time the 3rd TKI was started to loss of major hematologic response, loss of cytogenetic response, transformation to accelerated (AP) or blast (BP) phase, or death. Failure-free survival (FFS) was considered from start of 3rd TKI to event as defined for EFS, or loss of complete cytogenetic response (CCyR) or discontinuation because of toxicity.37 patients were treated: 29 with dasatinib after imatinib and nilotinib failure, and 8 with nilotinib after imatinib and dasatinib failure. The median age was 61 years (yrs) (range, 19 to 70). The median time on imatinib was 33 months (mo) and 15 (41%) had transformation before starting 2nd TKI. Median time on 2nd TKI was 7.7 mo. At the start of 3rd TKI, 16 pts (43%) were in chronic phase (CP), 9 (24%) in AP, and 12 (32%) in BP. Best response to 3rd TKI in CP was 1 major molecular response (MMR), 2 CCyR, 1 partial cytogenetic response (PCyR), 5 minor cytogenetic response (mCyR), 2 complete hematologic response (CHR), and 5 no responses (NR); in AP, there was 1 CCyR, 2 PCyR, 1 mCyR, 4 CHR, and 1 NR; in BP, 2 CCyR, 1 PCyR, 1 mCyR, 2 return to CP (RCP), and 6 NR. Four patients discontinued treatment because of toxicity despite an acceptable response. The median CCyR duration was 28 mo; only 2 pts in CP who achieved CCyR (1 had MMR) had a sustained response lasting 20 and 24 mo, respectively. Both received dasatinib after imatinib and nilotinib failure, and had G250E and H396R at start of dasatinib, respectively. The table shows median (in months) OS, EFS and FFS by disease stage.CPAPBPOVERALLNo.1691237OSNR19.64.818EFSNR4.748FFS204.7247 pts continue on therapy (all CP): 2 sustained CCyR (1 MMR), 1 PCyR (lost CCyR), 2 mCyR, 2 no cytogenetic response (1 lost mCyR).Use of 2nd generation TKI after failure to 2 TKI may induce responses in some pts but these are usually not durable except in some pts in CP. New treatment options are needed for these pts.

Imatinib Trough Plasma Concentration and Its Correlation with Clinical Response in Chronic Phase and Accelerated Phase of CML

Introduction: Imatinib mesylate trough plasma level is suggested to be one of the determinants of clinical efficacy in the treatment of patients with CML. Maintaining an imatinib trough level at or higher than 1000 ng/mL is suggested to be important for achieving optimal response.Aim: Evaluation of clinical relevance of monitoring imatinib trough plasma level.Material: Forty-seven imatinib treated CML patients (23 male/24 female, mean age 50±15.8 (SD) years) were included. Fifty one blood samples for pharmacokinetic analysis were taken. Patients treated with 400 mg of imatinib were in the first chronic phase. Patients treated with 600 mg of imatinib were in the first chronic phase resistant to imatinib 400 mg (loss of cytogenetic response) or accelerated phase at diagnosis. Mean imatinib treatment duration was 20 months (range 0.75–84 months). Blood samples were collected at 24 hours (most within ±3 hours) after the last dose of imatinib (steady state trough level).Results: Mean trough imatinib plasma levels (Cmin) in patients treated with 400 mg and with 600 mg were 1102±574 (SD) ng/mL (females 1091ng/mL, males 1118 ng/mL) and 1337±577 (SD) ng/mL (females 1498 ng/mL, males 1287 ng/mL) respectively. In patients treated with 400 mg of imatinib optimal response was achieved in 82.8% (N=29) with Cmin=1153 ng/mL (range 370 –2524). Suboptimal response was achieved in 2.8% (N=1) of patients with Cmin=820 ng/mL. Resistance was showed in 14% (N=5) with Cmin=865 ng/mL (range 10–2436). In patients achieving CCyR and MMR Cmin was 731.4 ng/mL and 1305 ng/mL respectively. In patients treated with 600 mg of imatinib optimal response was achieved in 58.8% (N=10) with Cmin=1358 ng/mL (range 790–2133). Suboptimal response was achieved in 11.7% (N=2) of patients with Cmin=1347 ng/mL (range 1302–1392). Resistance was found in 17.6% (N=3) with Cmin=1007 ng/mL (range 250–2085). There was no correlation between Cmin and age, body mass or body surface area.Discussion: Imatinib is the drug of choice for most patients with chronic and accelerated phase of CML. The mechanisms of resistance to imatinib are being investigated and the issue of non-compliance is considered. The data presented confirms the opinion that mean imatinib trough plasma level results should be analyzed together with other clinical data. In previous papers the importance of imatinib concentration monitoring in compliance evaluation was emphasized. The analysis presented suggests moreover considerable value of imatinib serum level monitoring in early diagnosis of resistance to treatment when analyzed together with fluctuations of the transcript level. High serum imatinib levels in resistant patients provide other than noncompliance mechanisms of resistance. Isolated cases when CMR is achieved and imatinib level is significantly below desirable value (581 and 383 ng/mL) remain remarkable. Imatinib serum level monitoring may appear particularly useful in monitoring of response in slow responders, when CCR and MMR is achieved beyond 12 months and 18 months of treatment respectively.Conclusions: The data presented confirms the importance of monitoring imatinib trough plasma level as an adequate evaluation of treatment efficacy and allows taking optimal therapeutical decisions when considered together with cytogenetic and molecular assessments.

Allogeneic Transplant Outcomes in Imatinib-Refractory Chronic Myeloid Leukaemia (CML) Are Similar to Transplant Outcomes in Imatinib-Responsive/Imatinib-Naïve CML and Appear To Be Predicted by the EBMT Risk Score.

Aims: To review the outcome of allogeneic stem cell transplantation (SCT) in imatinib refractory chronic myeloid leukaemia (CML).Methods: Outcomes of all allogeneic transplants performed after January 2001 for CML at our institution were retrospectively reviewed. Imatinib-refractory CML was defined as either lack of any cytogenetic response (CGR) after at least 6mths of imatinib, loss of CGR or progression to a more advanced disease stage (accelerated or blast phase) during imatinib therapy. Using the EBMT risk score (Lancet 1998; 352: 1087), transplant outcomes for imatinib refractory CML were compared with all other CML transplants performed during the same time period. Survival analysis was performed using the Kaplan-Meier product-limit and comparison of survival data via the log-rank test.Results: Of 31 allogeneic transplants (19M; 12F) performed for CML, 12 had been performed for imatinib refractory CML (no CGR to imatinib n=3; loss of CGR n=3; progression to AP n=3; progression to BC n=3), 5 in patients with imatinib responsive CML, and 14 in patients never exposed to imatinib. Median age at SCT was 40yrs (range 19–63yrs). Donor source included HLA-matched unrelated donors in 14 cases, HLA-identical siblings in 16 and other matched family donors in 1. Conditioning regimens included Cy/TBI (20 cases), Bu/Cy (8 cases), Flu/Mel (2 cases) and Flu/Cy (1 case); CsA + MTX was used as standard GVHD prophylaxis. EBMT risk scores were 1 (4 cases), 2 (6 cases), 3 (8 cases), 4 (5 cases), 5 (3 cases) and 6 (5 cases). At median follow-up post-SCT of 37mths (range 6–64mths), median PFS and OS are not reached; at 2yrs PFS, EFS and OS are 81%, 58% and 61% respectively. For patients with EBMT risk scores of 1–2 versus 3–4 versus 5–6, OS at 2 yrs post-SCT is 80%, 62% and 38% respectively (p=0.03). Based on EBMT risk score, no significant differences in PFS, EFS or OS were observed when comparing SCT for imatinib-refractory versus imatinib-responsive / imatinib-naïve CML.Conclusion: Our experience suggests that survival post-SCT for imatinib-refractory CML is similar to SCT for imatinib-responsive / imatinib-naïve CML. The EBMT risk score appears to remain useful in predicting survival post-SCT in imatinib-refractory CML.