A limited body of published evidence from retrospective studies and case reports suggests a potential role for dexmedetomidine as an adjunct therapy to provide sedation and analgesia to reduce narcotic withdrawal symptoms in pediatric patients.

Background The addition of tyrosine kinase inhibitors (TKIs) to chemotherapy improves the prognosis of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Single agent blinatumomab, a bi-specific T-cell engaging CD3-CD19 antibody construct, is more effective than multi-agent chemotherapy in relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL) and successfully achieves minimal residual disease (MRD) negativity in MRD positive patients. Limited data is available on the safety and efficacy of these agents in combination and uncertainties remain regarding the optimal use of blinatumomab +TKIs. Dual therapy with blinatumomab and TKIs may offer a safe and effective treatment option for relapsed and refractory patients without the incorporation of chemotherapy. Patients and Methods We report our retrospective experience in 18 patients who received blinatumomab +TKI for relapsed/refractory (R/R) Ph+ ALL (n=14), MRD+ Ph+ ALL (n=2) and chronic myeloid leukemia in lymphoid blast crisis (CML-LBC) (n=2). Ten patients received ponatinib; 8 patients received second generation TKIs (dasatinib, n=5; nilotinib, n=2; bosutinib, n=1). Blinatumomab was administered according to the package insert and TKI was initiated on day 1. Median follow up was 15 months and median number of blinatumomab +TKI cycles was 2 (range, 1-5). The median age was 47 years (range, 22-77). The median number of prior therapies was 2 (range, 1-8) and the median number of prior TKIs was 2 (range 1-4). Preexisting T315I mutations were present in one third of patients and 5 patients had relapsed following allogeneic stem cell transplant (alloHSCT). Results Transient grade 2-3 transaminase elevation was observed in 3 patients (ponatinib=2, dasatinib=1). Cytokine Release syndrome was observed in 2 patients. Transient neurotoxicity was observed in 3 patients (1patient with grade 3). All grade 2 and 3 toxicities were observed during the first cycle and all patients were successfully able to complete induction with blinatumomab +TKI. One patient on dasatinib experienced a PICC-associated DVT. There were no other vascular events observed. For patients with r/r disease the CR rate was 88% (14/16) with most of these remissions being MRD negative by flow and PCR (12/14). Both of the patients treated for MRD positivity achieved an MRD negative response. Among T315I mutated patients, 5/6 achieved a CR and 4/5 were MRD negative. The median time to remission was 35 days. The 1 year survival was 80% and the median overall survival following blinatumomab therapy was 45 months. Among 16 pts who achieved an initial response to blinatumomab +TKI, six have expired at the time of this analysis. At the time of relapse on combination therapy, 3/8 pts exhibited new T315I mutations. Of note, all of these were treated with blinatumomab in combination with a second generation TKI. All patients maintained their CD19 positivity at the time of relapse. Both pts with CML-LBC were able to move to a transplant following therapy with blinatumomab +TKI and both attained MRD negative status as measured by Bcr/Abl PCR values. In total, 10 patients treated with blinatumomab +TKI proceeded to alloHSCT, 7 of these are still alive. Median duration of response (DOR) was 5.1 months with maximum DOR of 23.3 months. Discussion While limited due to its retrospective nature and relatively small sample size, this data set begins to answer important regarding the safety and efficacy of blinatumomab +TKI. Combination therapy was effective at achieving rapid and deep responses in this refractory patient population. The toxicities observed with blinatumomab +TKI were in keeping with those seen with blinatumomab alone. However, care should be taken in regard to potential overlapping toxicities of TKIs and blinatumomab, such as hepatotoxicity. The study also suggests a role for blinatumomab treatment in patients with CML-LBC, a rare and difficult disease state to treat. The identification of T315I mutation at relapse in 40% of patients on blinatumomab +second generation TKIs supports further prospective studies with ponatinib and blinatumomab in combination. Finally, loss of C19, which has relevance with regards to the potential benefit of subsequent CD19-directed therapies such as chimeric antigen receptor T-cell therapy was not seen in patients treated with blinatumomab +TKI. Disclosures McCloskey: Jazz: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Takeda: Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Abbvie: Speakers Bureau; Novartis: Speakers Bureau. Gagnon:Amgen: Speakers Bureau. Goldberg:Cancer Outcomes Tracking and Analysis (COTA) Inc.: Equity Ownership; Bristol-Myers Squibb: Consultancy; COTA: Equity Ownership. Koprivnikar:Amgen: Speakers Bureau; Pfizer: Honoraria; Novartis: Speakers Bureau; Abbvie: Speakers Bureau.

Neurotoxicity related to the use of ifosfamide is a well-known complication. While the use of methylene blue is a known antidote, symptomatic treatment of the central nervous system (CNS) effects can be challenging. We present a case of class IV neurotoxicity with the successful treatment of symptomology. In this case report we present a 2-year-old female with relapsed alveolar rhabdomyosarcoma undergoing palliative chemotherapy. Patient received ifosfamide in addition to etoposide and mesna. The patient developed acute hallucinations, agitation, and delirium. The patient was transferred to the pediatric intensive care unit where she was administered dexmedetomidine overnight in addition to methylene blue. The patient awoke the next morning following discontinuation of the dexmedetomidine infustion and subsequently had no further central nervous system effects. This case demonstrates the novel use of an alpha-2 agonist in the treatment of neurotoxicity related to ifosfamide administration.

Background Patients with secondary acute myeloid leukemia (sAML) have poor outcomes compared to those with de novo AML. In 2017, liposomal daunorubicin and cytarabine (CPX-351) was FDA approved for the treatment of adults with newly diagnosed AML with myelodysplasia-related change (AML-MRC) or therapy-related AML (t-AML). In its landmark trial, CPX-351 has displayed significant improvement in overall survival (OS) compared to conventional 7+3 in patients 60-75 years of age with sAML. Gaps remain in the literature regarding the clinical use of CPX-351 in context of the FDA approved label. Here we evaluate real-world outcomes with disease response and molecular monitoring in patients treated with CPX-351. Methods Adults who received CPX-351 between September 2017 and December 2019 were identified. The primary endpoint was overall response rate (ORR), defined by complete remission (CR) and CR with incomplete hematologic recovery (CRi) according to the Revised IWG criteria. Additional outcomes of interest included molecular minimal residual disease (MRD) status post induction as measured by next-generation sequencing (NGS), ORR in patients with baseline TP53, and progression-free survival (PFS) in patients with CR/CRi, with and without MRD after induction. Mutations associated with clonal hematopoiesis (TET2, ASXL1, DNMT3A) were excluded from analysis of molecular MRD. Results Fifty-four patients were identified with baseline characteristics as shown in Table 1. Overall, the study population was elderly with the median age of 64 [IQR: 60-68], and 13 patients were younger than 60 years old. Six patients developed AML in the setting of a pre-existing myeloproliferative neoplasm (MPN). The most common indication for treatment with CPX-351 was antecedent MDS (42.6%), followed by de novo AML with MDS karyotype (24.1%), therapy-related AML (13%), and antecedent MPN (11.1%). NGS was performed prior to treatment with CPX-351 in all but one patient, and 88.7% had at least one molecular marker that is not identified as one of the mutations associated with clonal hematopoiesis. Most commonly identified molecular markers were TP53 (16/53, 30.2%), RUNX1 (10/53, 18.9%), SRSF2 (8/53, 15.1%), NRAS (7/53, 13.2%), and IDH2 and JAK2 (6/53, 11.3%, each). Most patients were hospitalized until hematologic recovery. However, 5 patients received induction in the outpatient setting, and an additional 6 patients were discharged early before hematologic recovery. Among the patients who were discharged early or underwent outpatient induction, 81.8% (9/11) were admitted for a complication. There were no deaths associated with outpatient induction. Overall, 46 patients (85.2%) experienced febrile neutropenia and 17 patients (31.5%) had bacteremia. Thirty-day and 60-day mortality were 9.3% and 14.8%, respectively. The ORR was 54%, and the response rates observed in patients who were younger vs older than 60 years were similar (41.7% vs. 57.9%, p=0.508). In patients who achieved a remission after induction, 56% (14/25) were MRD positive by NGS. Among those who had TP53 mutation at baseline, 14 were available for response assessment after induction. The ORR in this subgroup was 57% (8/14) and all but 3 (63%) were MRD negative by NGS. Consolidation with allogeneic transplant was performed in 18 patients (33%). Median OS was 10.4 mos. Median OS was similar for patients older or younger than 60 years (p=0.76). For patients achieving a CR/CRi, median OS had not been reached at the time of analysis but was significantly improved compared to those with refractory disease (6.1 mos, p=0.0007). Median OS or PFS did not differ significantly (p=0.68) based on MRD negativity (Figure 1). Conclusion This analysis demonstrates comparable response rates to the landmark trial (54% in our analysis vs. 47.7%). Outpatient induction and/or early discharge was safe and feasible in appropriately selected patients. While this analysis is limited by the small sample size, CPX-351 appeared effective in populations that were not included in the published randomized studies, such as patients below the age of 60 years old and those with antecedent MPN. Remission rates and MRD clearance was high among TP53 mutants. A considerable number of patients who achieved a remission remained MRD positive by NGS, but this did not impact PFS. Future studies should evaluate the impact of molecular MRD and allele frequency to further guide treatment. Disclosures Koprivnikar: Alexion: Speakers Bureau; BMS: Speakers Bureau; Novartis: Speakers Bureau; Amgen: Speakers Bureau. McCloskey:Takeda: Consultancy, Honoraria, Speakers Bureau; Novartis: Speakers Bureau; Abbvie: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Jazz: Consultancy, Honoraria, Speakers Bureau.