First Interim Analysis of the Italian Dante Study: De-Escalation before Treatment-Free Remission in Patients with Chronic Myeloid Leukemia Treated with First-Line Nilotinib

Introduction: Treatment-free remission (TFR) in chronic myeloid leukemia (CML) is demonstrated to be achievable and recommended for patients (pts) in sustained deep molecular response (sDMR) who can discontinue tyrosine kinase inhibitor (TKI) treatment and maintain responses in ~50% of cases. While the feasibility and safety of TKI cessation have been largely demonstrated, the strategies of TFR optimization are yet to be clarified. Studies (eg. DESTINY) investigating de-escalation, mainly after imatinib, suggested that a stepwise approach may favor TFR outcome. We present the interim results of the phase 2, prospective, multicenter DANTE study (NCT03874858) evaluating de-escalation and TFR in Italian pts with CML in chronic phase (CML-CP) treated with nilotinib (NIL). Methods: Adults with CML-CP treated with NIL 300 mg twice daily (bid) in first-line for ≥3 years who achieved sDMR for ≥1 year (≥MR 4.0;BCR-ABL level ≤0.01% IS) were enrolled in 27 centers. The study consisted of 4 phases: screening (week [wk] −4-0), consolidation (wk 0-48), TFR (wk 48-144), and follow-up (until wk 144). Ongoing treatment with ≥400 mg/day dose was allowed at study entry. During consolidation, pts were treated with NIL 300 mg once daily (qd). At the end of consolidation phase, pts with sDMR entered TFR phase and discontinued NIL;indeed, pts with at least major molecular response (MMR;BCR-ABL ≤0.1% IS), but without sDMR, continued NIL 300 mg qd. At any time, pts with loss of MMR returned to NIL 300 mg bid. During TFR phase, BCR-ABL levels were monitored monthly from wk 52-96, and then every 3 months. Pts on half-dose or full-dose NIL were monitored every 3 months. The primary endpoint is the percentage of pts in full treatment-free remission (FTFR) 96 wks after the start of consolidation phase. FTFR is defined as pts with MMR or better, including those who remained in discontinuation during TFR phase and those who are treated with half the standard dose. Key secondary endpoints include percentage of pts with sDMR at wk 48;TFR rate at wk 96 and 144;BCR-ABL kinetics and safety. The predictive role of digital droplet PCR is also evaluated as an exploratory objective. Results: Overall, 113 pts were screened and 107 entered consolidation phase. This interim analysis included 52 pts who reached the end of consolidation phase by data cut-off period (February 8, 2021). Of these 52 pts, 49 (94.2%) were ongoing by data cut-off and 3 (5.8%) discontinued the study (1 patient due to adverse event (AE) and 2 per patient's decision). Median age at study entry was 49.5 years. Median time from diagnosis was 5.6 years and median dose of prior NIL treatment was 600 mg/day for all pts except one who was on NIL 450 mg/day at baseline. Median duration of last sustained MR4 and MR4.5 were 30 and 16.5 months, respectively. Further details are listed in Table 1. At screening, molecular response categories were MR4.0 in 13.7%, MR4.5 in 23.1% and undetectable MR4.5 in 63.5% of pts. During consolidation phase, 5 (9.6%) pts discontinued prematurely: 2 pts restarted NIL full dose (3.8%) for MMR loss, 2 (3.8%) discontinued for AEs and 1 (1.9%) for pt decision. Overall, 47 pts completed consolidation: of them 40 (76.9%) sustained DMR and 7 (13.5%) maintained MMR but not sDMR. Of the 7 pts not sustaining DMR during consolidation, 6 regained DMR after a median of 4.4 months, while 1 pt was still in MMR by data cutoff. The 2 pts who lost MMR after 5 and 8 months regained MMR and 1 regained DMR by data cutoff after increasing NIL to 300 mg bid. Median time spent in consolidation phase was 11.7 months, and the evolution of response categories over time is shown in Figure 1. During consolidation phase, AEs were observed in 16 pts (30.8%), of them 2 (3.8%) pts had serious AEs: 1 patient had skin ulcers and COVID-19 related pneumonia, while 1 patient had unstable angina. No deaths and disease progressions were observed. Conclusions: DANTE is the first study that showed the safety and feasibility of NIL de-escalation before TFR in CML-CP pts with sDMR. Inter m results suggest that loss of MMR during de-escalation is rare. De-escalation strategy may lead to further improvement of TFR outcome and tolerability and may also preemptively support the identification of pts who may not be ready for discontinuation, with a tailored approach. To date, accuracy in predicting TFR outcome is still low, and the de-escalation setting may sharpen biological and clinical predictive factors, including the potential role of digital PCR. [Formula presented] Disclosures: Breccia: Abbvie: Honoraria;Pfizer: Honoraria;Novartis: Honoraria;Incyte: Honoraria;Bristol Myers Squibb/Celgene: Honoraria. Abruzzese: Incyte: Consultancy, Honoraria;Novartis: Consultancy, Honoraria;Pfizer: Consultancy, Honoraria;Bristol Myers Squibb: Consultancy, Honoraria. Stagno: InCyte: Consultancy, Honoraria;Pfizer: Consultancy, Honoraria, Other: Support for attending meetings and/or travel;Novartis: Consultancy, Honoraria, Other: Support for attending meetings and/or travel, Research Funding. Iurlo: Incyte: Speakers Bureau;Novartis: Speakers Bureau;Pfizer: Speakers Bureau;Bristol Myers Squibb: Speakers Bureau. Sportoletti: AstraZeneca: Consultancy, Honoraria;Janssen: Consultancy, Honoraria;AbbVie: Consultancy, Honoraria. Lemoli: Jazz, Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau;AbbVie, Daiichi Sankyo, Servier: Honoraria, Speakers Bureau;Celgene: Other: Support for attending meetings and/or travel. Siragusa: Novartis, CSL, Behring, Amgen, Novonoridsk, SOBI, Bayer: Consultancy, Honoraria, Speakers Bureau. Chiodi: Novartis: Current Employment.

Nursing Management of Frail Patients with Hematologic Malignancies during COVID-19 Pandemia in the Viterbo Domiciliary Care Unit: Data Analysis from March 2020 to March 2021

Introduction In the Viterbo province (3612 Km 2 divided into 60 municipalities) is operative a Domiciliary Hematologic Care Unit (DHCU) for clinical assistance to frail patients (pts) with hemopathies: DHCU nursing activity is done by 4 units who were employed during Covid-19 pandemia to avoid as possible risks of viral contagium due to hospital admissions of our pts. Aims To evaluate the entity and type of nursing management for frail pts followed by DHCU during the first year of Covid-19 pandemia. Methods All nursing activities from 3/2020 to 3/2021 in the lockdown framework were analysed. On the whole, 107 pts in 43 municipalities of Viterbo province were followed by DHCU nurses in the study period. Results Main features of the pts at baseline of domiciliary assistance are reported in the Table. At beginning of the study period (08/03/2020), 37 pts (34.5%) were already followed by DHCU, while 70 pts (65.5%) entered domiciliary assistance during the year of study. Median distance from DHCU central site to pts house was 25 Km [Interquartile range (IQR) 16 - 34]: distance from DHCU was < 20 Km in 32 cases (29.9%), ≥ 20 < 40 Km in 57 (53.2%) and ≥ 40 Km in 18 (16.9%). A total number of 2609 nursing accesses was done in the whole period. According to different procedures, 1152 blood samples were performed, with a median number of 7 (IQR 3 - 15) for each pts: in addition, there were 1040 accesses for chemotherapy (CHT) administration (108 cycles of azacytidine in 15 pts, 87 bortezomib-based cycles in 30 pts, 16 administrations of other CHTs in 2 pts) and 417 accesses for other procedures (260 venous catheter medications, 125 therapy other than CHT, 32 nursing assistances of transfusions or marrow aspirates). Finally, 20 pts were vaccinated at home with respective caregivers. During the entire study period, 2 pts (1.8%) developed Covid-19 infection while in home care. At the last follow-up (31/03/2021), 59 pts (55.1%) were alive and still followed by DHCU, 20 pts (18.6%) were alive and returned to sDay-Hospital (DH) setting due to improvement of clinical conditions and 28 pts (26.3%) died while in domiciliary assistance. Conclusions Domiciliary nurse assistance during Covid-19 pandemia allowed to follow in a safer way compared to standard DH/ordinary admission settings > 100 frail pts with hemopathies, most of them in 1 st or subsequent active lines of therapy, in a wide geographic area. In our opinion, this approach should represent the best type of assistance for a high rate of hematologic pts even beyond Covid-19 period of pandemia. [Formula presented] Disclosures: Stagno: Novartis: Consultancy, Honoraria, Other: Support for attending meetings and/or travel, Research Funding;Pfizer: Consultancy, Honoraria, Other: Support for attending meetings and/or travel;InCyte: Consultancy, Honoraria. Latagliata: BMS Cellgene: Honoraria;Pfizer: Honoraria;Novartis: Honoraria.

COVID-19 Infection in chronic myeloid leukemia after 1 year of the pandemic in Italy. A campus CML analysis

Background: An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) started in December 2019 in the province of Hubei in China. Italy was one of the most affected countries with many cases diagnosed already in February 2020 and a lockdown was declared on March 9th. Limited information has been reported with regard to the impact of the pandemic on chronic myeloid leukemia (CML) patients. Aims: To observe the temporal course of Covid-19 infection and the characteristics of positive patients. Methods: The Campus CML Italian group carried out a first survey on the management of CML patients during the lockdown. We launched a second survey during the pandemic phases 2 and 3, between May 2020 and January 2021. Results: We collected retrospective information on 8665 CML patients followed at 46 centers throughout the country. Within this cohort, we recorded 217 Covid-19-positive symptomatic patients (2.5%). Most patients (57%) were diagnosed as having Covid-19 infection between September 2020 and January 2021;30% were diagnosed in phase 1 (March-April 2020) and only 13% between May and August. Most of the positive patients were between 50 and 65 years (35%), while 26% had less than 50 years, 18.8% were between 65 and 75 years, and 11% had more than 75 years. A male prevalence was observed (73%). The median time from CML diagnosis to Covid-19 infection was 6 years (3 months-18 years). Fifty-six percent of patients presented concomitant comorbidities at the time of infection. When Covid-19 was diagnosed, 27% of patients were receiving imatinib, 26% nilotinib, 18% dasatinib, 8% ponatinib, 8% bosutinib, 2% asciminib, while 11% were not receive treatment. At the time of the infection, 74% of patients were in molecular remission, 6% in complete cytogenetic remission, 3% in partial cytogenetic remission, 6% in complete hematological response and 11% in treatment-free remission. At diagnosis, 28% of patients presented fever and respiratory symptoms, 13% cough, 10% isolated fever, 13% ageusia, 12% anosmia, 4% had more than 1 symptom, while 20% were completely asymptomatic. Twenty-one patients (9.6%) required hospitalization without the need of respiratory assistance, 18 (8.2%) were hospitalized for respiratory assistance, 8 (3.6%) were admitted to an ICU, while 150 patients (69%) were only quarantined. Twenty-three percent of patients discontinued TKI therapy during the infection. The source of contagion was familiar in 49% of patients, 18% due to work, 3% in healthcare professionals, whereas in 30% was not known. Twelve patients died due to Covid-19 infection with a mortality rate of 5.5% in the positive cohort and of 0.13% in the whole cohort. Five patients reported consequences post-infection: 1 patient reported a Guillan-Barrè syndrome, 1 patient a maculopapular rash, 1 patient a pulmonary fibrosis, 1 patient a bacterial endocarditis and 1 patient was diagnosed as having alterations of the microcirculation. Summary/Conclusion: This study reports the 1-year of data on the Covid- 19 infection in a specific hematological malignancy in the European country first hit by the pandemic. A longer follow-up is needed to further define the impact of Covid-19 infection sequelae in CML patients.

Second-Line Bosutinib in Elderly CML Patients: Final Results of Best Study

Introduction: The median age of CML patients failing a first-line TKI because of resistance or intolerance is higher than 60 years. Bosutinib (BOS), dasatinib (DAS) and nilotinib (NIL) have similar second-line efficacy, but in elderly patients DAS and NIL toxicity is more frequent and more clinically relevant. BOS safety profile may be an added value in this setting, but the approved initial dose of 500 mg OAD may be higher than necessary. Aims: All TKIs have been tested in CML patients at a fixed initial dose, with dose reductions in case of toxicity. On the contrary, the aim of our study was to evaluate the efficacy and the tolerability of low-dose second-line BOS in elderly CML patients, using the molecular response at given timepoints to increase the dose only in selected patients, thus finding the minimum effective dose. Methods: A prospective phase 2 single-arm multicenter study has been designed by the GIMEMA CML Working Party (NCT02810990). Study design: All patients started BOS 200 mg OAD for 2 weeks (ârun-inâ period), then the dose was increased to 300 mg OAD;after 3 months, patients with BCR-ABLIS transcript ≤ 1% continued 300 mg OAD, while in patients with transcript > 1% the dose is furtherly increased to 400 mg OAD, in absence of relevant toxicity. The primary endpoint was the rate of MR3 at 12 months. Key inclusion criteria: > 60 yrs old, chronic phase CML, intolerance or failure of any first-line TKI (2013 ELN criteria), absence of T315I or V299L mutation. Results: Sixty-three patients have been enrolled. Median age: 73 yrs (range 60-90). Reasons for switching to BOS: Intolerance 63%, resistance 37%. First-line TKI: Imatinib 83%, DAS 11%, NIL 6%. All patients reached at least 1-year observation. Due to the emergency situation caused by SARS CoV2 spread in Italy, few data are still missing, but final results will be presented onsite. Maximum BOS dose: 400 mg OAD, 19%;300 mg OAD, 76%;200 mg OAD, 5%. At baseline, 17% of patients were already in MR3;MR3 rates at 3, 6 and 12 months were 44%, 54% and 59%, respectively. The cumulative rate of patients achieving or maintaining a MR3 by 12 months was 67%;patients achieving MR4 or MR4.5 by 12 months were 44% and 24%, respectively. Overall, 30%, 29% and 8% of patients had 1 log, 2 logs or > 3 logs reduction from baseline BCR-ABLIS transcript level (67% of patients had a molecular improvement from baseline). Selected adverse events: Acute coronary syndromes, 4 patients;pericarditis, 2 patients;peripheral arterial thrombosis, 1 patient;no pleural effusions were observed. Events leading to permanent treatment discontinuation: 2 unrelated deaths, 7 adverse events, 4 unsatisfactory responses (without progressions), 1 second neoplasia. Fourty-nine patients are still on BOS at the last contact: 10% of them on 400 mg OAD, 61% on 300 mg OAD, 29% on 200 mg OAD. Conclusions: These results trial showed that in elderly patients intolerant to or failing a first-line TKI BOS may be highly effective and better tolerated at a dose lower than 500 mg OAD, namely at 300 mg OAD.