Molecular Response In Patients Research Articles

CD302 predicts achievement of deep molecular response in patients with chronic myeloid leukemia treated with imatinib

AbstractAchieving a deep molecular response (DMR) is a prerequisite for treatment-free remission in chronic myeloid leukemia (CML) and a key milestone for patients with CML. This study identified patients unlikely to achieve a 5-year DMR through differential expression of cluster of differentiation (CD) genes, and clinical variables at diagnosis. Peripheral blood samples (n = 131) from patients treated with imatinib or nilotinib underwent transcriptomic microarray profiling. The decision-tree analysis delineated 2 distinct poor-risk (PR) cohorts, distinguished by high 3-month BCR::ABL1% (PR-1), or high CD302 expression (PR-2). The 5-years DMR achievement rate was significantly lower in both PR groups than in the good-risk (GR) group in patients treated frontline with imatinib (0% vs 27% vs 83%; P < .0001) or nilotinib (PR-2 vs GR, 17% vs 83%; P = .02). Gene-set enrichment analysis revealed reduced expression of cell cycle–related genes in PR-2, as well as increased metabolism and STAT3 pathway genes, which has previously been linked to leukemic cell persistence and resistance to tyrosine kinase inhibitors. Moreover, PR-2 had a higher frequency of CD34+CD302+ and CD14+CD302+ cells than GR samples. Strategies aimed at targeting STAT3 and/or metabolic pathways associated with high CD302 may provide novel therapeutic approaches that could help improve treatment outcomes and eradicate residual disease.

The Depth of the Molecular Response in Patients with Chronic Myeloid Leukemia Correlates with Changes in Humoral Immunity.

Background and Objectives: The effective treatment of chronic myeloid leukemia leads to the restoration of proper immune system function. We aimed to investigate fluctuations in circulating cytokines, angiogenic factors and complement components in patients with CML during the first year of treatment with TKI and correlate them with the degree of achieved molecular response. Material and Methods: We recruited 31 patients with newly diagnosed CML. Peripheral blood and bone marrow samples were obtained, and concentrations of serum proteins were measured using an immunology multiplex assay. Results: The study cohort was divided into two groups of optimal or non-optimal in accordance with the European Leukemia Net (ELN) guidelines. We found significantly higher concentrations of C1q, C4 and C5a in serum after 3 months of TKI treatment in patients who achieved optimal responses in the 6 months after diagnosis. The most alterations were observed during 12 months of therapy. Patients in the optimal response group were characterized by higher serum concentrations of TGF-β, EGF, VEGF, Angiopoietin 1, IFN-γ and IL-8. Conclusions: The later plasma concentrations of complement components were significantly increased in patients with optimal responses. The changes after 12 months of treatment were particularly significant. Similar changes in bone marrow samples were observed.

Evaluating Effectiveness and Safety of Flumatinib for Chronic Phase Chronic Myeloid Leukemia in (CML-CP) without Optimal Response (Warning, Failure) to Imatinib or/and Dasatinib

Introduction Flumatinib is a novel second-generation BCR-ABL1 targeted kinase inhibitors (TKI) with better efficacy and safety than first generation TKIs in first-line treatment of chronic myeloid leukemia in chronic phase (CML-CP). In the previous phase III study, newly diagnosed CML-CP patients receiving flumatinib achieved higher treatment responses and safety than imatinib. When it comes to the patients not achieving the optimal response to TKIs, flumatinib is potentially a better option, nonetheless the robust evidence is unavailable. This study reports the effectiveness and safety of switching to flumatinib in patients who have not achieved the optimal molecular response to imatinib or/and dasatinib. Methods This prospective, multicentre study enrolled Philadelphia Chromosome-Positive (Ph+) CML-CP patients aged ≥18 years and who failed to achieve the optimal response with imatinib or/and dasatinib between March 2021 to October 2022. All patients were treated with flumatinib 600 mg once a day and followed up to 24 months. The primary endpoint of the study was rate of major molecular response (MMR) at 12 months as defined by European LeukemiaNet 2020 recommendations (BCR-ABL1 transcript level ≤0.1% in peripheral blood on RT-PCR assay on International Scale [IS]) and safety was the secondary endpoint assessed with CTCAE 4.03 version. In addition, the optimal molecular response in either the warning or failure patients was evaluated at 3, 6 and 12 months respectively, after switching to flumatinib, and the difference in effectiveness was also analyzed from the available mutation subtypes. Results Overall, 94 patients with Ph+ CML-CP were included in the study. The median (range) age of the patients were 53 (19.0-84.0) years old and 61.7% of the patients were males. A total of 38 (40.4%) patients reported warning response from the previous TKIs whereas 56 (59.6%) of patients reported treatment failure to the previous TKIs. Seventy-seven (81.9%) patients have been treated with one TKI, either imatinib or dasatinib, and 17 (18.1%) have been treated with both prior to the study. Overall, 25 (54%) patients achieved MMR at 12-months follow-up compared to the baseline (Figure 1). The rates of optimal molecular response at 3- and 6-months were also improved compared to the baseline. The optimal molecular response was 76(88%) at 3 months, and 52(73%) at 6 months. Subgroup analysis with previous response to TKIs revealed that flumatinib improved the rates of optimal molecular response in both warning and failure groups. Switching to flumatinib from imatinib or/and dasatinib have been reported with an enhanced optimal molecular response in patients who experienced warning compared with those who had treatment failure after the TKIs with 38 (100%) vs 38 (79%), 29 (91%) vs 23 (59%) and 15 (68%) vs 10 (42%) at 3-, 6- and 12-months respectively (Figure 2). Similarly, the rates of optimal molecular response were improved in patients without mutations compared to those having mutations, 65 (90%) vs 9 (75%) at 3 months, 46 (77%) vs 5 (56%) at 6 months and 23 (59%) vs 1 (20%) at 12 months respectively. The most common adverse events (AEs) were diarrhea in 17 (18%), rash in 11 (12%), bloating in 11 (12%), and thrombocytopenia in 11 (12%) patients. Common hematological AEs of grade 3/4 were thrombocytopenia in 7 (7%), anemia in 3 (3%) and leucopenia in 1 (1%) patients. Conclusion For Ph+ CML-CP patients without the optimal molecular response in previous imatinib or/and dasatinib, flumatinib is a better alternative to the existing treatments. In addition, if the patients were switched to flumatinib earlier, the optimal response was achieved faster. The grade 3/4 AEs were mainly hematologically related, whereas the gastrointestinal events were mostly of grade 1-2.

POSTER: MDS-345 Nature of Clinical Response and Depth of Molecular Response in Patients With TP53-Mutant Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Treated With Magrolimab With Azacitidine

POSTER: MDS-345 Nature of Clinical Response and Depth of Molecular Response in Patients With TP53-Mutant Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Treated With Magrolimab With Azacitidine

MDS-345 Nature of Clinical Response and Depth of Molecular Response in Patients With TP53-Mutant Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Treated With Magrolimab With Azacitidine

MDS-345 Nature of Clinical Response and Depth of Molecular Response in Patients With TP53-Mutant Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Treated With Magrolimab With Azacitidine

A scoring system to predict molecular responses in patients with chronic myeloid leukemia in the chronic phase receiving initial imatinib therapy

Objective: To develop a scoring system to predict molecular responses in patients with chronic myeloid leukemia in the chronic phase (CML-CP) receiving initial imatinib therapy. Methods: Data from consecutive adults with newly diagnosed CML-CP treated by initial imatinib was interrogated and subjects were distributed randomly into training and validation cohort, in a ratio of 2∶1. Fine-gray models were applied in the training cohort to identify co-variates of predictive value for major molecular response (MMR) and MR4. A predictive system was built using significant co-variates. The predictive system was then tested in the validation cohort and the area under the receiver-operator characteristic curve (AUROC) was used to estimate accuracy of the predictive system. Results: 1 364 CML-CP subjects receiving initial imatinib were included in this study. Subjects were distributed randomly into training cohort (n=909) and validation cohort (n=455) . In the training cohort, the male gender, European Treatment and Outcome Study for CML (EUTOS) Long-Term Survival (ELTS) intermediate-risk, ELTS high-risk, high WBC (≥130×10(9)/L or 120×10(9)/L, MMR or MR4) and low HGB (<110 g/L) at diagnosis were significantly related with poor molecular responses and were given points based on their regression coefficients. For MMR, male gender, ELTS intermediate-risk and low HGB (<110 g/L) were given 1 point; ELTS high-risk and high WBC (≥130×10(9)/L) , 2 points. For MR4, male gender was given 1 point; ELTS intermediate-risk and low HGB (<110 g/L) were given 2 points; high WBC (≥120×10(9)/L) , 3 points; ELTS high-risk, 4 points. We divided all subjects into 3 risk subgroups according to the predictive system above. Cumulative incidence of achieving MMR and MR4 in 3 risk subgroups was significantly different in both training and validation cohort (all P values <0.001) . In the training and validation cohorts, the time-dependent AUROC ranges of MMR and MR4 predictive systems were 0.70-0.84 and 0.64-0.81, respectively. Conclusions: A scoring system combining gender, WBC, HGB level and ELTS risk was built to predict MMR and MR4 in CML-CP patients receiving initial imatinib therapy. This system had good discrimination and accuracy, which could help phsicians optimize the selsction of initial TKI-therapy.

Practical Application of Circulating Tumor-Related DNA of Human Papillomavirus in Liquid Biopsy to Evaluate the Molecular Response in Patients with Oropharyngeal Cancer.

Recent findings have shown that human papillomavirus (HPV) DNA is present in the blood as a tumor-specific biomarker (circulating tumor-related HPV; ctHPV) in patients with HPV-related oropharyngeal cancer (HPV-related OPC). The molecular response (MR) in patients with HPV-related OPC can be defined as the change in the number of ctHPV copies in relation to its initial quantity. The optimal model for assessing the MR using a liquid biopsy (LB) should be based on the E6/E7 sequences of the viral genome. MR assessment can help to evaluate the intensity of ongoing treatments in relation to the tumor response. The evaluation of the residual disease at the end of therapy may also be performed by MR assessment. If a partial MR (pMR) is found, caution is indicated and a subsequent LB should be considered, due to the likelihood of disease progression. Complete radiological and clinical responses together with a complete MR (cMR) convincingly indicate a low risk of treatment failure. Moreover, molecular recurrence (Mrec) during a follow-up, confirmed in two consecutive assays, even despite the lack of any other clinical or radiological symptoms of progression, indicates patients at high risk of disease recurrence. In conclusion, MR by ctHPV assessment may hasten the early detection of disease progression, at any stage of the management of the patient with HPV-related OPC.

Radiotherapy Induces Innate Immune Responses in Patients Treated for Prostate Cancers.

Radiotherapy is a curative therapeutic modality used to treat cancers as a single agent or in combination with surgery and chemotherapy. Advanced radiotherapy technologies enable treatment with large fractions and highly conformal radiation doses to effect free-radical damage to cellular DNA leading to cell-cycle arrest, cell death, and innate immune response (IIR) stimulation. To understand systemic clinical responses after radiation exposure, proteomic and metabolomic analyses were performed on plasma obtained from patients with cancer at intervals after prostate stereotactic body radiotherapy. Pathway and multivariate analyses were used to delineate molecular alterations following radiotherapy and its correlation with clinical outcomes. DNA damage response increased within the first hour after treatment and returned to baseline by 1 month. IIR signaling also increased within 1 hour of treatment but persisted for up to 3 months thereafter. Furthermore, robust IIR and metabolite elevations, consistent with an early proinflammatory M1-mediated innate immune activation, were observed in patients in remission, whereas patients experiencing prostate serum antigen-determined disease progression demonstrated less robust immune responses and M2-mediated metabolite elevations. To our knowledge, these data are the first report of longitudinal proteomic and metabolomic molecular responses in patients after radiotherapy for cancers. The data supports innate immune activation as a critical clinical response of patients receiving radiotherapy for prostate cancer. Furthermore, we propose that the observed IIR may be generalized to the treatment of other cancer types, potentially informing multidisciplinary therapeutic strategies for cancer treatment.

Ponatinib and blinatumomab for Philadelphia chromosome-positive acute lymphoblastic leukaemia: a US, single-centre, single-arm, phase 2 trial

Ponatinib and blinatumomab are effective therapies in patients with Philadelphia chromosome-positive (Ph-positive) acute lymphoblastic leukaemia, and their combination might be a promising treatment option. In this study, we aimed to evaluate this chemotherapy-free strategy. We did a single-centre, single-arm, phase 2 study at the University of Texas MD Anderson Cancer Center, Houston, TX, USA, in patients aged 18 years or older with newly diagnosed or relapsed or refractory Ph-positive acute lymphoblastic leukaemia or chronic myeloid leukaemia in lymphoid blast phase. Patients with an ECOG performance status of 2 or less who had a total bilirubin concentration two-times the upper limit of normal (ULN) or less (≤2·4 mg/dL), alanine aminotransferase and aspartate aminotransferase concentration no more than three-times the ULN, and serum lipase and amylase concentrations no more than three-times the ULN were eligible for inclusion. Ponatinib 30 mg orally and continuous intravenous blinatumomab 28 μg over 24 h (for 28 days each cycle) were given in combination for up to five 42-day cycles, followed by ponatinib monotherapy. Patients received 12 doses of intrathecal chemotherapy as CNS prophylaxis. The primary endpoints were complete molecular response (defined as absence of a detectable BCR-ABL1 transcript by PCR at a sensitivity of 0·01%) in patients with newly diagnosed disease and overall response in patients with relapsed or refractory disease or chronic myeloid leukaemia in lymphoid blast phase. All assessments were done according to the intention-to-treat principle. The trial completed its original target accrual and was amended on March 23, 2022, to enrol an additional 30 patients, thus increasing the sample size to 90 patients. The trial is registered with ClinicalTrials.gov, NCT03263572, and it is ongoing. Between Feb 6, 2018, to May 6, 2022, 60 (83%) of 72 patients assessed were enrolled and received ponatinib and blinatumomab (40 [67%] patients had newly diagnosed Ph-positive acute lymphoblastic leukaemia, 14 [23%] had relapsed or refractory Ph-positive acute lymphoblastic leukaemia, and six [10%] had chronic myeloid leukaemia in lymphoid blast phase). 32 (53%) patients were men and 28 (47%) were women; 51 (85%) patients were White or Hispanic; and the median age of participants was 51 years (IQR 36-68). The median duration of follow-up for the entire cohort was 16 months (IQR 11-24). Of patients with newly diagnosed Ph-positive acute lymphoblastic leukaemia, 33 (87%) of 38 evaluable patients had a complete molecular response. 12 (92%) of 13 evaluable patients with relapsed or refractory Ph-positive acute lymphoblastic leukaemia had an overall response. 11 (79%) had a complete molecular response. Five (83%) of six patients with chronic myeloid leukaemia in lymphoid blast phase had an overall response. Two (33%) had a complete molecular response. The most common grade 3-4 adverse events that occurred in more than 5% of patients were infection (22 [37%] patients), increased amylase or lipase concentration (five [8%] patients), increased alanine aminotransferase or aspartate aminotransferase concentration (four [7%] patients), pain (four [7%] patients), and hypertension (four [7%] patients). One (2%) patient discontinued blinatumomab due to tremor. Three (5%) patients discontinued ponatinib secondary to cerebrovascular ischaemia, portal vein thrombosis, and coronary artery stenosis in one patient each. No treatment-related deaths were observed. The chemotherapy-free combination of ponatinib and blinatumomab resulted in high rates of complete molecular response in patients with newly diagnosed and relapsed or refractory Ph-positive acute lymphoblastic leukaemia. Patients with newly diagnosed Ph-positive acute lymphoblastic leukaemia could be spared the toxicities associated with chemotherapy and the need for allogeneic haematopoietic stem-cell transplantation in first response. Takeda Oncology and Amgen.

Nature of Clinical Response and Depth of Molecular Response in Patients with TP53 Mutant Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Treated with Magrolimab with Azacitidine

Nature of Clinical Response and Depth of Molecular Response in Patients with TP53 Mutant Myelodysplastic Syndromes (MDS) and Acute Myeloid Leukemia (AML) Treated with Magrolimab with Azacitidine

CML-466 Asciminib Provides Durable Molecular Responses in Patients With Chronic Myeloid Leukemia in Chronic Phase (CML-CP) With the T315I Mutation: Updated Efficacy and Safety Data From a Phase I Trial

In CML-CP, the BCR::ABL1 T315I mutation confers resistance to previously approved ATP-competitive tyrosine kinase inhibitors (TKIs), except ponatinib and olverembatinib. In a previous analysis of the phase I, dose-escalation trial X2101, asciminib-a BCR::ABL1 inhibitor that binds to the ABL myristoyl pocket-demonstrated efficacy and a favorable safety profile in heavily pretreated patients with T315I-mutated CML. We report updated efficacy and safety data in patients with CML-CP with the T315I mutation (data cutoff: January 6, 2021). Provide updated safety and efficacy data for patients with T315I-mutated CML-CP after added exposure. Patients with T315I-mutated CML-CP and treated with ≥1 prior TKI were enrolled and received asciminib 200mg twice daily (BID). 48 patients were included; 25 patients (52.1%) received ≥3 prior TKIs. At data cutoff, treatment was ongoing in 27 patients (56.3%). 45 of 48 patients were evaluable (BCR::ABL1IS >0.1% at baseline) for major molecular response (MMR); 3 were excluded for BCR::ABL1 atypical transcripts. Among evaluable patients, 19 (42.2%) achieved MMR by week 24 and 22 (48.9%) by week 96. Evaluable patients included 26 ponatinib-pretreated and 19 ponatinib-naive patients; 34.6% and 68.4%, respectively, achieved MMR by week 96. The probability of maintaining MMR for ≥96 weeks was 84% (95% CI, 68.1%-100.0%). 23 of 37 patients (62.2%) with BCR::ABL1IS >1% at baseline achieved BCR::ABL1IS ≤1% by week 96. The safety/tolerability profile of asciminib remained favorable after ≈9 months of added exposure (median duration of exposure, 2.08 years; range, 0.04-4.13 years). The most common (≥10%) grade ≥3 adverse events (AEs) were lipase increase (18.8%, all asymptomatic elevations) and thrombocytopenia (14.6%). Arterial occlusive events occurred in 4 patients (8.3%); none led to dose adjustment/interruption/discontinuation. AEs leading to discontinuation occurred in 5 patients (10.4%). Only 2 study deaths, both due to COVID-19, occurred in this patient population. After a median exposure of >2 years, asciminib monotherapy 200mg BID exhibited a sustained, favorable safety profile and clinical efficacy in patients with T315I-mutated CML-CP-a population with high unmet medical need. This updated analysis confirms asciminib as a treatment option for patients with T315I-mutated CML-CP, including those previously treated with ponatinib.

Deep molecular response in patients with chronic phase chronic myeloid leukemia treated with the plasminogen activator inhibitor-1 inhibitor TM5614 combined with a tyrosine kinase inhibitor.

We recently showed that pharmacological inhibition of plasminogen activator inhibitor-1 (PAI-1) activity, based on TM5614, increases cell motility and induces the detachment of hematopoietic stem cells from their niches. In this TM5614 phase II clinical trial, we investigated whether the combination of a PAI-1 inhibitor and tyrosine kinase inhibitors (TKIs) would induce a deep molecular response (DMR) in patients affected by chronic myeloid leukemia (CML) by quantifying BCR-ABL1 transcripts. Patients with chronic phase CML treated with a stable daily dose of TKIs for at least 1year and yielding a major molecular response (MMR) but not achieving MR4.5 were eligible for this study. After inclusion, patients began to receive TM5614 as well as a TKI. The primary objective was an evaluation of the cumulative incidence of patient progression from an MMR/MR4 to MR4.5 by 12 months. Thirty-three patients were enrolled in the study. The median age was 59.0 years and 58% were male. No Sokal high-risk patients were enrolled in this trial. The median TKI treatment duration was 4.8 years. At the start of this study, seven patients and 26 patients received imatinib and second-generation TKIs, respectively. The cumulative MR4.5 incidence by 12 months was 33.3% (95% confidence interval, 18.0%-51.8%). The cumulative MR4.5 spontaneous conversion over 12 months was estimated as 8% with TKIs alone based on historical controls. The halving time of BCR-ABL1 at 2months was significantly shorter for patients who achieved an MR4.5 , by 12 months than for the other patients (cutoff value: 48 days; sensitivity: 0.80; specificity: 0.91; ROC-AUC: 0.83). During this study, bleeding events and abnormal coagulation related to the drug were not reported, and TM5614 was found to be highly safe. TM5614 combined with TKI was well tolerated and induced MR4.5 in more patients than stand-alone TKI treatment.

Natural killer cell dynamics and its association with response to imatinib-treated patients with chronic myeloid leukemia

ObjectiveThis study aims to assess the effect of natural killer (NK) cells and natural killer T (NKT) cells on response to imatinib (IM) therapy in patients with chronic myeloid leukemia (CML).BackgroundNK cells and NKT cells play a vital role in innate immunity against tumors. NKT cells recognize tumor cells by receptor-ligand interaction. After contact with the ligand, NKT cells activate NK cells through inflammatory cytokines [interferon-gamma (IFN-γ) and interleukin 2].Patients and methodsA total of 48 newly diagnosed patients with CML (chronic phase) were included. They were followed up for 1 year after the start of IM therapy and were categorized into IM-responder patients with CML (n = 23) and IM-resistant patients with CML (n = 25). Flow cytometry was used to measure NK and NKT cells. Serum levels of IFN-γ were determined by enzyme-linked immunoassay.ResultsWe found that NK cell% and NKT cell% were increased in the IM-responder group after 1 month of IM therapy. IFN-γ was increased at both presentation and 1 month after the start of IM therapy. Major molecular response was achieved earlier in the IM-responder group, with increased NK cell%, absolute count of NK cell, and IFN-γ.ConclusionWe conclude that NK cells have a critical role in the response of patients with CML to IM therapy and are a predictor of major molecular response in patients with CML.

Treatment of Ropeginterferon Alpha-2b Achieves Hematologic Remission and Molecular Response in Patients with Hydroxyurea- and/or Anagrelide-Resistant/Intolerant Myeloproliferative Neoplasms

▪Background:Ropeginterferon alpha-2b (Ropeg) is a novel pegylated interferon-alpha approved for the treatment of polycythemia vera (PV) in Europe and Taiwan. Prior to its approval in Taiwan, the major options for patients with myeloproliferative neoplasms (MPNs) included hydroxyurea (HU) and/or anagrelide. Patients who are HU/anagrelide resistant/intolerant have limited options, as ruxolitinib is not subsidized by the national health insurance in Taiwan for PV. In 2017, the manufacturer provided a compassionate use program (CUP) for patients who were HU and/or anagrelide resistant/intolerant. Herein, we assessed the efficacy and safety of Ropeg in 20 MPN patients.Methods:To be eligible, patients must be resistant or intolerant to currently available therapies for MPN in Taiwan, mainly HU and anagrelide. Patients with autoimmune disorders, psychiatric illness, and acute/chronic infections were excluded. An accelerated dosing regimen was used, starting from 250 µg, and increased by 100 µg every two weeks until it reached the target dose of 500 µg, if no self-reported discomforts or abnormalities in biochemical or hematological profiles were observed. Efficacy assessments included hematologic parameters, phlebotomy need, and JAK2V617F allele burden. Hematologic remission was defined as platelets ≤400 x 10^9/L and white blood cells <9.5 x 10^9/L for essential thrombocythemia (ET), and platelets ≤400 x 10^9/L, white blood cells <10 x 10^9/L, and hematocrit <45% with no phlebotomy in the past 3 months for PV. Molecular response was defined as a reduction in JAK2V617F allele burden of at least 50% from baseline if baseline value was less than 50%, and a reduction of at least 25% from baseline if the baseline level was at least 50%. Each case was independently reviewed and approved for the use of Ropeg by both Institutional Review Board and the Ministry of Health and Welfare in Taiwan.Results:A total of 20 patients received treatment, which included 14 PV, 4 ET, 1 post-ET myelofibrosis (MF), and 1 pre-fibrotic primary MF (Table 1). There were 12 female and 8 male patients with a median age of 56.1 years old. Of these 20 patients, 18 had JAK2V617F mutation and 5 had a history of thrombosis. Of the 18 ET and PV patients, 13 achieved hematologic remission. The ET patients seemed to achieve hematologic remission faster than PV patients (19.3 vs. 33.2 weeks). Of the 18 patients with JAK2V617F mutation, 7 PV patients and 1 post-ET MF patient achieved molecular response, which took a median of 46 weeks after Ropeg treatment. Reduction in JAK2V617F allele burden was observed in 12 patients. One MF patient discontinued treatment due to disease progression. Another PV patient discontinued treatment due to acute myeloid leukemia transformation, although after treatment, the patient returned to PV state and continued Ropeg treatment. Overall, the drug was well tolerated, as most of the treatment-related adverse events (AEs) were mild to moderate. The AE profile was consistent with those from the phase 3 PROUD/CONTI-PV study. There were no unbearable side effects that led to treatment discontinuation.Conclusion:Our study provided evidence in the efficacy and safety of Ropeg for the treatment of HU-/anagrelide-resistant/intolerant MPNs. Hematologic remission was observed in ET and PV patients, whereas molecular response was observed in only PV patients, possibly due to the small sample size of ET patients. Our experience with Ropeg suggests it to be a promising option for the treatment of MPNs with drug-resistance/intolerance. [Display omitted] DisclosuresChen: PharmaEssentia: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Amgen, Celgene, Novartis, and Panco Healthcare: Honoraria. Shih: PharmaEssentia Co: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene Ltd: Research Funding; Ltd: Research Funding; Novartis: Research Funding. OffLabel Disclosure:Ropeginterferon alfa-2b is a novel interferon alpha indicated for the treatment of polycythemia vera in Europe and in Taiwan. This abstract describes the use of this agent for the treatment of myeloproliferative neoplasm patients with hydroxyurea/anagrelide resistance/intolerance.

The Impact of Somatic Mutations upon the Response to Combination Therapy with Ruxolitinib and Interferon in MPN Patients

Introduction: The Philadelphia-negative myeloproliferative neoplasms (MPN) are associated with driver mutations in JAK2, CALR, and MPL genes. Non-driver mutations affect disease progression and treatment response. Combination therapy with pegylated interferon-alpha2 (IFN) and ruxolitinib has recently been shown to induce hematologic and molecular responses in patients (pts) with MPN. We studied 25 pts by targeted next generation sequencing (NGS) of 42 genes and investigated the impact of somatic mutations (mut) on treatment response.Methods: Twenty-five MPN pts with polycythemia vera (PV) (n=16, all JAK2V617F) and myelofibrosis (MF) (n=9, JAK2V617F (6), CALR (1), MPL (1), triple-negative (1)) participated in the study. NGS was performed on the Illumina platform on DNA from peripheral blood at baseline and after 24 months of combination therapy. Data were analyzed using Biomedical Genomics workbench and VarSeq. Variants with coverage <100x, variant allele frequency (VAF) <1%, introns and germline variants, and SNPs with minor allele frequency >1% were excluded. A mut with VAF <1% in either a pre- or post-treatment sample was retained if VAF was >1% in the paired sample. However, a mut with a number of mutated reads below 7 was considered absent. Only pathogenic mut were reported. Statistical analysis was done using either chi-square test or Wilcoxon signed rank/rank sum test in R 4.0.2. A p-value <0.05 was considered significant. The ELN and IWG-MRT response criteria were used.Results: At baseline and 24 months, PV-pts had a mean number of mut of 2.3 and 2.4, and MF-pts 2.2 and 3.0, respectively. In all pts, 0 and 1 (0/4%) patient had no mut, 10 and 7 (40/28%) had 1 mut, 10 and 9 (40/36%) had 2 mut, and 5 and 8 (20/32%) had ≥ 3 mut at baseline and 24 months, respectively.In PV, 1 (6%) achieved CR and 3 (19%) achieved PR and 12 (75%) achieved NR. In MF, 4 (44%) achieved CR and 1 (11%) achieved PR and 4 either NR, PD, SD or CI. There was no association between pts achieving CR/PR or NR and median number of mut at baseline (CR/PR: 1, range 1-3) or (NR: 2, range 1-8), (p=0.28). Excluding driver mut, there was still no significant association.In all JAK2V617F positive pts, the median JAK2V617F allele burden (%JAK2V617F) decreased from 37% (range: 1.9-95) at baseline to 22.5% (range: 0-85) at 24 months. In pts achieving CR or PR (n=7), the reduction in %JAK2V617F was greater (median: 42% to 18%, p<0.05) compared with pts achieving NR (n=12) (median: 30% to 22%, p<0.005).Stratified according to molecular response (MR) (n=4) or non-MR (n=13), median % JAK2V617F at baseline was 40 (21-95) and 43 (42-70) in non-MR and MR, respectively, and 31 (11-85) and 13 (1.8-25) in non-MR and MR, respectively during treatment. At baseline, pts achieving MR had no non-driver mut and pts achieving non-MR had a median number of non-driver mut of 1 (range: 0-7) (p<0.02). Eight pts were not evaluable because they were either CALR or MPL positive, triple-negative, or had a baseline JAK2V617F ≤ 20%.In all pts, there were 30 non-driver mut in 15 genes at baseline and 40 non-driver mut in 19 genes at 24 months of therapy. At baseline and at 24 months, TP53 occurred in 6 and 6 (24%), TET2, ASXL1, RUNX1, or SF3B1 in 2 and 3 (8/12%), and CBL, DNMT3A, or SRSF2 in 2 and 2 (8%) pts, respectively. Eleven new non-driver post-treatment mut occurred in 9 pts and were more prevalent in pts with MF (6/9, 66%) compared to pts with PV (3/16, 19%), p<0.02. However, the VAF was low (median 1.2%, range 1.02% - 3.6%) and none of the new 11 post-treatment mut appeared in the same gene.Discussion and Conclusions: Earlier studies have shown an association between poor response to IFN and number of mut or high molecular risk mut. In this study, the presence of non-driver mut was associated with a significantly poorer molecular response. However, there was no association between the presence or type of non-driver mut and clinico-hematologic response. At 24 months, there was an evolution of subclones with a significantly higher number of new subclones appearing in pts with MF compared to pts with PV. However, the VAF was low and none of the acquired mut appeared in the same gene contradictory to another study showing an association between treatment-emergent mut in DNMT3A and treatment with IFN. In conclusion, these data show that a clinico-hematologic response is achievable during combination therapy despite the presence of non-driver mutations at baseline. DisclosuresBjørn: Novartis: Other: Ruxolitnib. Hasselbalch: Novartis, AOP Orphan: Consultancy, Other: Advisory Board. OffLabel Disclosure:Interferon-alpha for treatment

Thyroid autoimmunity and hypothyroidism are associated with deep molecular response in patients with chronic myeloid leukemia on tyrosine kinase inhibitors

PurposeThyroid alterations including de novo appearance of thyroid autoimmunity are adverse effects of tyrosine kinase inhibitors, used in solid and hematologic cancer therapy, but the relationship between thyroid alterations during this treatment and the outcome of chronic myeloid leukemia remains unclear. Aim of this study was to investigate whether the presence of thyroid alterations may affect the clinical outcome of chronic myeloid leukemia on tyrosine kinase inhibitors.MethodsWe evaluated thyroid function and autoimmunity in 69 chronic myeloid leukemia patients on long-term therapy looking at the association between thyroid abnormalities and disease molecular response.ResultsOverall, 24 of 69 (34.8%) had one or more thyroid abnormalities during therapy. A high percentage of patients (21/69, 30.4%) showed thyroid autoimmunity (positive thyroid autoantibodies with ultrasound hypoechogenicity), while clinical and subclinical hypothyroidism and subclinical hyperthyroidism were, respectively, found in 4 of 69 (5.8%) and 3 of 69 (4.3%) of cases. Second-generation tyrosine kinase inhibitors resulted significantly associated (14/32, 43.7%) with Hashimoto’s thyroiditis, compared to first generation (7/37, 18.9%; p = 0.03). Interestingly, we also found a significant association between euthyroid (14/26, 53.8%) and hypothyroid Hashimoto’s thyroiditis (4/26, 15.4%) in patients with deep molecular response, as compared to euthyroid (3/43, 7%; p = 0.0001) and hypothyroid (0/43, 0%; p = 0.02) Hashimoto’s thyroiditis patients with major molecular response.ConclusionsOur study confirms and extends our knowledge on the tyrosine kinase inhibitors effects on thyroid, showing that thyroid autoimmunity is frequently observed in chronic myeloid leukemia patients on long-term therapy and is associated with a better oncological response.

Abstract LB054: Confirmation of target inhibition and anti-tumor activity of the SHP2 inhibitor RMC-4630 via longitudinal analysis of ctDNA in a phase 1 clinical study

Abstract RMC-4630 is a potent, selective, orally bioavailable allosteric inhibitor of SHP2, a central node in the RAS signaling pathway. Preclinical data have demonstrated that RMC-4630 can shrink tumors carrying certain mutations in the RAS pathway such as KRASG12C, NF1LOF, and BRAFClass3. Longitudinal circulating tumor DNA (ctDNA) was isolated from blood using GuardantOMNI in 80 patients with relapsed/refractory solid tumors in the phase 1 dose-escalation trial of RMC-4630 (NCT03634982) to characterize and confirm RAS pathway mutations and to evaluate molecular responses in patients receiving RMC-4630 monotherapy. Safety, PK and efficacy findings from this study are reported in a separate abstract. 78 of 80 patients had baseline somatic mutations detected in plasma, of which 60 were either KRASG12X, NF1LOF, or BRAFClass3; 48 of these 60 patients also had on-treatment ctDNA assessments and these patients constitute the population reported here. 9 of 48 patients (19%) had KRASG12C detected at baseline, available scan results and a ctDNA sample after 4 weeks of receiving RMC-4630. A decrease in KRASG12C variant allele frequency (VAF) was detected in 5/9 patients (56%) with clearance in 1 patient with a partial response. Decrease in KRASG12C VAF was associated with change in tumor volume (PCC=0.85, p=0.008), preceding scan results by approximately 1 month, suggesting that change in KRASG12C VAF may be an early measure of drug activity or possibly response. 5 of 48 patients (10%) had NF1LOF detected at baseline. A decrease, or stability in NF1LOF VAF on treatment compared to baseline was detected in 4 (80% of all NF1LOF patients). The decrease in NF1LOF VAF was not associated with change in tumor volume and may represent effects of RMC-4630 on a subclone harboring NF1LOF. One patient had a detectable BRAFClass3 mutation at baseline, which decreased in VAF on treatment compared to baseline. Of the remaining patients there were 12 KRASG12D, 9 KRASG12V and other KRASG12X. The majority progressed with an increase in VAF of all mutations including KRASG12X, suggesting that the KRASG12X-containing clone is responsible for escape from single agent RMC-4630. In most instances the increase in KRASG12X VAF in blood preceded determination of clinical progression. Longitudinal assessment of ctDNA indicates that some patients with RAS-addicted tumors undergo a molecular response on treatment with the SHP2 inhibitor RMC-4630. Citation Format: Josie L. Hayes, Marianna Koczywas, Sai-Hong Ignatius Ou, Pasi A. Janne, Jose M. Pacheco, Susanna Ulahannan, Judy S. Wang, Howard A. Burris, Jonathan W. Riess, Caroline McCoach, Michael S. Gordon, Anna Capasso, Ariel Chen, Richa Dua, Bojena Bitman, Martha Guerra, Hongfang Wang, Xiaolin Wang, Eric Haura. Confirmation of target inhibition and anti-tumor activity of the SHP2 inhibitor RMC-4630 via longitudinal analysis of ctDNA in a phase 1 clinical study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB054.

Proteomic Profiling Identifies c-KIT and 53BP1 As Resistance Factors of AML Relapse Post Allogeneic Stem Cell Transplantation with G-CSF/Plerixafor/Busulfan-Fludarabine Conditioning

The CXCR4 inhibitor plerixafor in combination with G-CSF disrupts stroma-leukemia interactions, mobilizing leukemia cells from their niche microenvironment. This combination in conjunction with chemotherapy has been investigated in clinical trials in AML. We recently reported a phase 1/2 study of CXCR4 inhibition combined with chemotherapy prior to allogeneic stem cell transplantation (allo-SCT) (G-CSF-plerixafor (G+P) plus busulfan-fludarabine (Bu+Flu), Konopleva, et al. BMT 2015) and confirmed that patients who had not achieved remission at the time of transplant (“non-CR”) had poorer outcome than patients who were in remission at the time of allo-SCT (“CR”). Similar results have been reported in other clinical studies. Risk factors, such as the presence of circulating blasts and unfavorable cytogenetics are associated with poor outcome, but the molecular responses in patients treated with CXCR4 inhibitor and conditioning chemotherapy prior to allo-SCT are unknown. We investigated the hypothesis that the CXCR4 inhibition-driven preparative regimen modulates distinct signaling networks, which vary depending on disease status.Utilizing reverse phase protein array (RPPA), we profiled 157 proteins in 36 cellular signaling and functional groups in samples collected from ten AML patients who were studied in the phase 1/2 trial (Table1). Five CR patients had less than 1% blasts in bone marrow (BM) and no blasts in peripheral blood (PB) before conditioning regimen (baseline, day -9). Five non-CR patients had BM blasts ranging from 10-72% and PB blasts from 0-45%. Here we denote samples from “CR” patients as “normal” and from “non-CR” patient as “AML”. All “AML” patients with blasts had persistent blasts after G+P plus conditioning, ranging from 4-64%. However, four of five “AML” and five “normal” patients achieved complete response to allo-SCT. Engraftment was observed in all patients. Disease progression following allo-SCT was observed in four of five “AML” but not in “normal” patients. Overall survival in “AML” was significantly shorter than in “normal” patients (non-CR = 260 ± 55 days, CR = 2028 ± 103 days, P < 0.001).RPPA analysis of samples prior to conditioning (day -9) revealed that 9 proteins in 9 signaling pathways were expressed differently in “normal” and “AML” samples. Among them, c-KIT, 53BP1, a P53-binding DNA repair protein, and CIAP (a SMAC and IAP family member) had significantly higher expression in “AML”.G+P treatment significantly modulated 7 proteins in 4 pathways in “AML” samples, and 22 proteins in 13 signaling and functional groups in “normal” samples (Fig 1A). As a result, 22 proteins in 14 signaling and functional groups were differentially expressed in “AML” and “normal” samples post G+P treatment (day -7) (Fig 1B). Among the top 10 distinct proteins, PI3Kp110A, P53BP1, SMAD1 and p-C-JUN S73 had higher expression, and P38MAPK, p-HER2 Y1248, P-CADHERIN, SYK, P21 and TAU had lower expression in “AML” samples.Treatment with G+P plus Bu+Flu conditioning modulated 10 proteins in 7 signaling pathways in “AML” samples, and altered 40 proteins in 13 signaling pathways in “normal” samples (Fig 1C). As a result, G+P plus Bu+Flu conditioning caused significant differences in expression of 16 proteins in 14 signaling and functional groups in “AML” vs. “normal” samples (day -3) (Fig 1D). Among the top 10 distinct proteins, PI3Kp110A, XRCC1, p-ERA S118, 53BP1, and BCL2 had higher expression, and MIG6, SYK, TAU, p-AKT T308 and MEK1 had lower expression in “AML” samples. Notably, c-KIT and 53BP1 in “AML” baseline samples were persistently expressed at high levels in samples from G+P and G+P plus Bu+Flu treated patients, suggesting that c-KIT and 53BP1 mediated signaling might play a role in therapeutic resistance and disease relapse in patients with active disease at the time of transplant.In summary, CXCR4 inhibition combined with Bu+Flu conditioning triggered distinct molecular responses, resulting in differential signaling between “normal” and “AML” cells prior to allo-SCT. The persistence of c-KIT and 53BP1 might play a role in resistance and contribute to relapse in AML. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Deeper Molecular Response in Patients (pts) with Newly Diagnosed Chronic Myeloid Leukemia Chronic Phase (CML-CP) Patients Receiving Radotinib 300 Mg BID or Imatinib: Rerise 36 Months Follow-up

BackgroundIn RERISE phase 3 study, radotinib demonstrated significantly higher and faster rates of major molecular response (MMR) than imatinib in patients with newly diagnosed CML-CP. By 12 and 24 months follow up, MMR (BCR-ABL1IS≤ 0.1%) and MR4.5 (BCR-ABL1IS ≤ 0.0032%) in radotinib 300 mg twice daily (bid) were higher than imatinib group. Also, early molecular response (EMR) at 3- or 6- months could predict better outcomes in both radotinib or imatinib groups. To confirm the long-term benefits and risks of radotinib 300mg bid and imatinib 400mg qd, we update the results from RERISE phase 3 study based on a minimum follow-up of 36 months.Methods241 patients were randomized 1:1:1 to radotinib 300 mg bid (n=79), radotinib 400 mg bid (n=81), or imatinib 400 mg once daily (qd) (n=81). Methods have been previously reported (Blood 2015 126:476). We evaluated MMR and MR4.5, overall survival (OS), and progression-free survival (PFS) by 36 months. Also, we analyzed the clinical impacts of early and deeper molecular response in radotinib 300mg bid and imatinib 400mg qd groups.ResultsBy 36 months, MMR was significantly higher in patients receiving radotinib 300 mg bid compared with imatinib 400mg qd (Table). The MR4.5 rate by 36 months was also higher for radotinib compared to imatinib (43% vs 28%; P=0.0538). More patients treated with radotinib achieved additional MMR and MR4.5 since 12 months and time to MR4.5 was faster in radotinib than imatinib (median 924 vs 1,095 days; P=0.2534). Of 59 patients who had MMR by 36 months, 18 patients achieved MMR, and of 34 patients who had MR4.5 by 36 months, 22 patients achieved MR4.5 since 12 months. Estimated OS and PFS rate at 36 months were not significantly different in two groups (98% vs 97%; P=0.0554, 99% vs 95%; P=0.4707). Treatment failure was lower in radotinib group compared with imatinib group (Table).The safety profiles were consistent with those previously reported and most of adverse events (AEs) have developed within 12 months. Since 12 months, newly developed AEs such as rash, nausea/vomiting, pruritis, musculoskeletal pain, fatigue, hyperbilirubinemia, and ALT elevation, etc have shown minimal increase by 36 months FU.ConclusionsWith a minimum 36 months follow-up, radotinib continued to demonstrate significantly higher rates of MMR and MR4.5 than imatinib in newly diagnosed CML-CP. Also, these responses with radotinib were earlier and deeper compared with imatinib. These results still demonstrate that radotinib can be one of the standards of care in newly diagnosed CML-CP and support the higher possibility of treatment- free remission (TFR) on frontline therapy with radotinib. [Display omitted] DisclosuresKim:Il-Yang: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

The impact of FLT3 mutation clearance and treatment response after gilteritinib therapy on overall survival in patients with FLT3 mutation-positive relapsed/refractory acute myeloid leukemia.

The FLT3 inhibitor gilteritinib has clinical activity in patients with FLT3‐mutated (FLT3 mut+) relapsed/refractory (R/R) acute myeloid leukemia (AML). The impact of FLT3 mutation clearance and the achievement of composite complete remission (CRc) and complete remission/complete remission with partial hematologic recovery (CR/CRh) on overall survival (OS) in patients with FLT3 mut+ R/R AML treated with single‐agent gilteritinib in a phase 1/2 trial were evaluated. Using next‐generation sequencing, a FLT3‐ITD variant allele frequency of ≤10−4 was used to define FLT3‐ITD clearance in patients with no morphologic leukemia (ie, CRc). A total of 108 patients with FLT3‐ITD‐positive (FLT3‐ITD+) R/R AML were analyzed; 95 of these patients had received ≥80‐mg/day gilteritinib. Ten of the 95 patients had FLT3‐ITD clearance; eight of these 10 patients achieved CRc and were considered negative for measurable residual disease. There was a trend toward longer OS in patients who attained CRc with FLT3‐ITD clearance (131.4 weeks) versus those who achieved CRc and did not have FLT3‐ITD clearance (n = 41; 43.3 weeks; HR = 0.416; p = 0.066). Among patients treated with ≥80‐mg/day gilteritinib who achieved CR/CRh (n = 24), seven had FLT3‐ITD clearance. Among patients who received 120‐mg/day gilteritinib, those who achieved CR/CRh had a longer median OS (70.6 weeks) and higher 52‐week survival probability (66.7%) than patients who did not achieve CR/CRh (n = 71; median OS, 41.7 weeks; 52‐week survival probability, 20.2%). Overall, these data suggest that gilteritinib can induce deep molecular responses in patients with FLT3‐ITD+ R/R AML, and in the setting of CRc or CR/CRh, these responses may be associated with prolonged survival.