Citations

Abstract Remediation of struggling learners is a challenge faced by all educators. In recognition of this reality, and in light of contemporary challenges facing infectious diseases (ID) fellowship program directors, the Infectious Diseases Society of America Training Program Directors’ Committee focused the 2018 National Fellowship Program Directors’ Meeting at IDWeek on “Remediation of the Struggling Fellow.” Small group discussions addressed 7 core topics, including feedback and evaluations, performance management and remediation, knowledge deficits, fellow well-being, efficiency and time management, teaching skills, and career development. This manuscript synthesizes those discussions around a competency-based framework to provide program directors and other educators with a roadmap for addressing common contemporary remediation challenges.

Treatment of polycythemia vera (PV) with the Murine Double Minute 2 (MDM2) antagonist, idasanutlin, in a phase 1 trial was reported by our group to be well tolerated with a high overall response rate (Mascarenhas et al, Blood. 2019 Jun 5). A global, phase 2 trial is currently underway evaluating idasanutlin in hydroxyurea (HU) resistant/intolerant PV patients (NCT03287245). MDM2, a negative regulator of TP53 is upregulated in PV CD34+ cells and inhibition of MDM2 targets PV hematopoietic stem/progenitor cells (HSPC) (Lu et al, Blood. 2014;124(5):771-90). Additional trials of MDM2 antagonists have shown promise, however, there is concern that these agents have the potential to induce TP53 mutations or promote expansion of TP53 mutated clones. Resistance to MDM2 inhibitors has been evaluated in solid tumor cell lines and attributed to either the emergence of de novoTP53 mutations or the selection of TP53 mutated clones. (Michaelis et al, Cell Death Dis. 2011;2:e243; Skalniak et al, Cancers. 2018;10(11)). The effect of MDM2 inhibition on TP53 mutant clones is of particular interest in myeloproliferative neoplasms (MPNs). TP53 mutations have been reported with a low allele burden in ~15% of chronic MPN patients (Kubesova et al, Leukemia. 2018;32(2):450-61), however, TP53 loss of heterozygosity and rapid expansion of TP53 mutant clones is associated with transformation to blast phase (Lundberg et al, Blood 2014,123:2220-8). As reported, in the idasanutlin PV trial, 1/13 patients were identified to have a baseline pathogenic TP53 mutation in hematopoietic cells (VAF 5.5%), using a deep sequencing assay with a limit of detection (LOD) of VAF 0.5%. This patient was a non-responder to idasanutlin and upon treatment had an increasing JAK2V617F and TP53 mutant VAF. End of study hematopoietic cell specimens of all patients were deep sequenced (LOD 0.1%) and revealed that 4 additional patients harbored detectable TP53 mutations after idasanutlin treatment with VAF ranging from 1-12%. In each sample, 1-5 unique TP53 mutations were identified, all within the hotspot domain of the TP53 gene. Deeper sequencing of baseline and follow-up samples revealed these mutations were present at a subclonal level (VAF 0.1-5.5%) and increased over time, indicating that treatment with the MDM2 antagonist promoted expansion of already existing TP53 mutant clones (Table 1, Figure 1). None of the patients who lacked a TP53 mutation at baseline developed a TP53 mutant clone with idasanutlin treatment. There was no clear association of presence of TP53 mutations with prior HU, anagrelide or interferon exposure. There has been careful monitoring of patients to determine whether the expanding TP53 clone has clinical ramifications. Patients were on study for a median of 54 weeks (23-131). The only patient who exemplified resistance to idasanutlin was the single patient with a high burden TP53 mutation (37%). All other patients were taken off study due to patient choice/toxicity. Furthermore, all TP53 mutant and non-mutant patients have had stable disease with no evidence of progression to MF or AML. Sequencing of 2 patients post-discontinuation of idasanutlin revealed that the VAF of the TP53 mutant clones decreased since the agent was discontinued. Updated patient molecular data post-treatment discontinuation will be reported at the meeting. To investigate whether idasanutlin induces de novo TP53 mutations in PV myeloid cells we performed long term HSPC cultures. Mononuclear cells from 6 distinct PV patients were treated continuously with idasanutlin (500 nM) over ~6 weeks and DNA from both treated and untreated colonies were analyzed using next generation sequencing with a LOD of 2% VAF and no TP53 mutations were detected. The combined in vitro and clinical data reveals that treatment with an MDM2 antagonist is not associated with the emergence of de novoTP53 mutations but rather the expansion of prior existing TP53 clones. This does not appear to have clinical repercussions, however, close monitoring of these patients is essential. We recommend that patients be screened for TP53 mutations prior to treatment with an MDM2 antagonist and that if present the TP53 mutant VAF be followed during their treatment course. Resistance to MDM2 inhibition is likely dependent on the TP53 mutant VAF and further studies will need to clarify the ideal dosing schedule of MDM2 antagonists and/or combinatorial therapy to prohibit TP53 mutant clonal expansion. Disclosures Houldsworth: Cancer Genertics: Other: stock in; Sema4: Employment. Rossi:Sema4: Employment. Kiladjian:AOP Orphan: Honoraria, Research Funding; Celgene: Consultancy; Novartis: Honoraria, Research Funding. Rampal:Agios, Apexx, Blueprint Medicines, Celgene, Constellation, and Jazz: Consultancy; Constellation, Incyte, and Stemline Therapeutics: Research Funding. Mascarenhas:Incyte: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Roche: Consultancy, Research Funding; Merck: Research Funding; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; CTI Biopharma: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Research Funding; Promedior: Research Funding; Merus: Research Funding; Pharmaessentia: Consultancy, Membership on an entity's Board of Directors or advisory committees. Hoffman:Merus: Research Funding.

Summary Survival prediction in essential thrombocythaemia (ET) and polycythaemia vera (PV) is currently based on clinically‐derived variables; we examined the possibility of integrating genetic information for predicting survival. To this end, 906 molecularly‐annotated patients (416 Mayo Clinic; 490 University of Florence, Italy), including 502 ET and 404 PV, were recruited. Multivariable analysis identified spliceosome mutations to adversely affect overall ( SF3B1 , SRSF2 in ET and SRSF2 in PV) and myelofibrosis‐free ( U2AF1 , SF3B1 in ET) survival; TP53 mutations predicted leukaemic transformation in ET; “adverse” mutations occurred in 51 (10%) ET and 8 (2%) PV patients. We confirmed the independent survival effect of adverse mutations [hazard ratio (HR) 2·4, 95% CI 1·6–3·5], age >60 years (6·6, 4·6–9·7), male sex (1·8, 1·3–2·4) and leukocytosis ≥11 × 10 9 /l (1·6, 1·1–2·2), in ET, and adverse mutations (7·8, 3·1–17·0), age >67 years (5·4, 3·6–8·1), leukocytosis ≥15 × 10 9 /l (2·8, 1·8–4·2) and thrombosis history (2·0, 1·4–2·9), in PV. HR‐based risk point allocation allowed development of three‐tiered mutation‐enhanced international prognostic systems (MIPSS) which were validated in both cohorts and performance was shown to be superior to conventional scoring systems. Spliceosome mutations enhance survival prediction in ET and PV and identify patients at risk for fibrotic progression. TP53 mutations predict leukaemic transformation in ET.

Objectives:With the introduction of novel immune therapeutics for the treatment of disseminated malignancies, we sought to evaluate whether deliberate sequencing of immunotherapy before/after conventional cytotoxic chemotherapy would have an impact on clinical outcomes in patients with previously treated metastatic melanoma. We sought to evaluate whether or not ipilimumab immunotherapy administered before or after cytotoxic chemotherapy (nab-paclitaxel+bevacizumab, AB) would impact clinical outcomes.Methods:We conducted a randomized phase 2 clinical trial of patients with BRAF wild-type metastatic melanoma (up to 2 prior therapies) who received either: (A) AB followed by ipilimumab therapy at progression; or (B) ipilimumab followed by AB treatment at progression. The primary goal of the study was a comparison of AB versus ipilimumab progression-free survival, with secondary clinical and laboratory endpoints.Results:This study did not reach full accrual due to concurrent Food and Drug Administration approval of anti-programmed cell death 1 agents. Nevertheless, the available data suggests a cumulative therapeutic advantage to the sequential use of ipilimumab followed by AB. Correlative laboratory data revealed a favorable effect on systemic immune homeostasis in patients receiving AB therapy, of potential interest in further investigations, especially in the context of chemotherapy/immunotherapy combinations.Conclusion:Albeit limited in scope, our data suggest that cytotoxic therapy with nab-paclitaxel and bevacizumab appear to favorably alter systemic parameters of immune function of potential benefit in combination T-cell directed immune checkpoint inhibitor therapy.

Prior to the advent of the monoclonal antibody trastuzumab, human epidermal growth-factor receptor 2 (HER2)-positive (HER2+) breast cancer (BC) was associated with an aggressive clinical course and poor survival outcomes. In the era of effective HER2-directed therapies, median survival rates for patients with metastatic HER2+ BC now approach 5 years. Despite these improvements, the majority of affected patients unfortunately die from disease. Therapies to overcome treatment resistance are being actively pursued. One strategy has been to target the cyclin-dependent kinases 4/6 (CDK4/6), as they are downstream of HER2 and many of the cellular pathways driving resistance to HER2-targeted therapies, and play a key role in proliferation by controlling transition through the G1 restriction point to the S phase of the cell cycle. In this article, we review the published literature with regard to the rationale for CDK4/6-directed therapies in HER2+ BC and discuss ongoing clinical research and new challenges in the field.

Abstract Background: Polycythemia vera (PV) is characterized by erythrocytosis and overactive JAK/STAT activity. The RESPONSE trial compared ruxolitinib (RUX), a JAK1/JAK2 inhibitor, with best available therapy (BAT) in patients (pts) with PV intolerant of or resistant to hydroxyurea according to modified European LeukemiaNet criteria. RUX was superior to BAT in achieving the primary endpoint (21% vs 1%; P<0.0001), and 60% of pts randomized to RUX achieved protocol-defined hematocrit (HCT) control through Wk 32 vs 20% of pts randomized to BAT (J Clin Oncol32:5s, 2014; suppl, abstract 7026). However, the actual phlebotomy rate between Wks 8−32 was only 20% in pts randomized to RUX compared with 62% in pts randomized to BAT, and 85% of pts in the RUX arm continued to receive treatment at the median 81-wk follow-up, suggesting most pts derived some benefit from RUX. Therefore, an analysis was conducted to evaluate the clinical efficacy of RUX in pts who did and did not achieve protocol-defined HCT control. Methods: Phlebotomy-dependent PV pts with splenomegaly, aged ≥18 years, and resistant to or intolerant of HU were enrolled. Pts were required to have HCT between 40%−45% 14 days prior to randomization; those who did not could enter a phlebotomy control period to achieve a HCT in this range within 14 days of randomization. Eligible pts were randomized 1:1 to RUX or BAT. BAT pts could cross over to receive RUX from Wk 32 if they had not met the primary endpoint, or after Wk 32 due to protocol-defined disease progression. The primary composite endpoint comprised HCT control and a ≥35% reduction from baseline in spleen volume (SV) at Wk 32. HCT control was defined as lack of phlebotomy eligibility between Wks 8−32 with no more than 1 phlebotomy eligibility between randomization and Wk 8. Phlebotomy eligibility was based on protocol-defined HCT values (regardless of receipt of phlebotomy), and pts with missing data or assessments outside of protocol-defined time windows were considered non-responders. In pts who were HCT control non-responders (HCT-N) as defined by protocol, time to second phlebotomy eligibility was evaluated. For this analysis, pts without phlebotomy eligibility were excluded and phlebotomies in the first 8 wks were not considered. Patient-reported outcomes were evaluated in both HCT control responders (HCT-R) and HCT-N, including the 14-item modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and the Patient Global Impression of Change (PGIC). Results: Of 222 randomized pts (RUX, n=110; BAT, n=112), most were male (RUX, 60%; BAT, 71%) and the median age (range) was similar between treatment arms (RUX, 62.0 [34.0–90.0]; BAT, 60.0 [33.0–84.0]). Although pts had a HCT between 40% and 45% within 14 days prior to randomization (with or without phlebotomy), 24% of pts had a HCT >45% on Day 1 (similar between treatment arms) illustrating that many pts have poor HCT control over short intervals of observation. RUX treatment resulted in long-term benefits on HCT levels, even in pts who did not achieve protocol-defined HCT control through Wk 32. Among the RUX HCT-R group, the probability of maintaining HCT response was 97% at 48 wks and 87% at 80 wks. Most BAT pts crossed over to receive RUX immediately after the Wk 32 visit (84% between Wks 32 and 48). In the RUX HCT-N pts, the median time to subsequent phlebotomy eligibility was 52 wks, compared with 21 wks for BAT HCT-N pts (Figure). Compared with the entire BAT group, more RUX-R and RUX-N pts had a ≥50% improvement in the MPN-SAF total symptom score at Wk 32 (RUX-N, 38%; RUX-R, 40%; BAT, 4%). Median changes from baseline at Wk 32 in key symptoms such as tiredness (RUX-N; −50%; RUX-R, −49%; BAT, −4%), itching (RUX-N, −88%; RUX-R, −97%; BAT, −2%), and night sweats (RUX-N, −100%; RUX-R, −97%; BAT, 4%) were also greater among RUX-R and RUX-N pts than BAT pts. RUX-N and RUX-R pts were also more likely to consider their symptoms to be “much improved” or “very much improved” on the PGIC compared with BAT pts (RUX-N, 57%; RUX-R, 74%; BAT, 13%). Conclusion: Among pts receiving RUX who did not achieve protocol-defined HCT control, the median time to subsequent phlebotomy eligibility was 1 year. In contrast, pts on BAT had a median time to subsequent phlebotomy eligibility of 21 wks. Furthermore, pts in the RUX arm achieved meaningful improvements in PV-related symptoms, regardless of meeting the endpoint of HCT control, while pts treated with BAT showed worsening or no improvement. Figure 1 Figure 1. Disclosures Verstovsek: Incyte Corporation: Research Funding. Off Label Use: Ruxolitinib is a JAK1/JAK2 inhibitor approved for the treatment of patients with intermediate or high-risk myelofibrosis, including primary myelofibrosis, post polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Kiladjian:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Mesa:Incyte Corporation: Research Funding; CTI: Research Funding; Gilead: Research Funding; Genentech: Research Funding; Eli Lilly: Research Funding; Promedior: Research Funding; NS Pharma: Research Funding; Sanofi: Research Funding; Celgene: Research Funding. Jones:Incyte Corporation: Employment, Equity Ownership. He:Incyte Corporation: Employment, Equity Ownership. Li:Novartis Pharmaceuticals: Employment, Equity Ownership. Habr:Novartis Pharmaceuticals: Employment, Equity Ownership. Vannucchi:Novartis Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract Introduction: The clinical phenotype of patients with myeloproliferative neoplasms (MPNs) including primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocytosis (ET) who manifest WHO grade 1 (on a 0-3 scale) for intramedullary fibrosis is poorly defined, and may represent MPN patients in a transitional state. We have specifically observed patients with existing PV and ET who manifest clinical progression towards a post PV/ET phenotype (IWG-MRT criteria) yet fail to progress to a 2+ marrow fibrosis. In contrast, the 2008 WHO definition of PMF does not require a minimum fibrosis threshold as long as patients meet the diagnostic criteria. In this study, we retrospectively analyzed the clinical characteristics and outcomes of MPN patients with 1+ marrow fibrosis. Methods: MPN patients with WHO grade 1 (scale 0-3) fibrosis within two institutional databases were identified. The clinical characteristics, laboratory, and outcome data were collected. Data were compared between PMF and PV/ET patients. 2008 IWG-MRT criteria were applied to PV/ET patients with exclusion of fibrosis component. Results: 91 MPN patients with WHO grade 1 fibrosis were identified, PMF in 33 patients (36%), PV in 37 (41%), ET in 20 (22%), and MPN-U in 1 (1%). The population characteristics are reported in Table 1. The majority (56%) of patients exhibited one or more symptoms (weight loss, night sweats, early satiety, bone pain, fatigue). The presence of symptomatic disease was similar between groups, with 52% PMF versus 57% PV/ET exhibiting at least one symptom. Symptoms were more severe in the PMF group with DIPSS risk of intermediate 2 or higher being present in 39%(PMF) versus 29% (PV/ET). Erythrocyte transfusion dependence occurred in a small percentage of overall population (9%), and was seen primarily in the PMF group (6/8 patients). Incidence and severity of splenomegaly was higher in the PMF group, with 55% having splenomegaly versus 43% of the PV/ET group. A higher incidence of a leukoerythoblastic blood smears was seen in PMF (45%) than PV/ET (38%). Two or more prior medical therapies were utilized in 45/90 (49%) of patients, with the most common prior therapies including hydroxyurea (71%), pegylated interferon (28%), anagrelide (18%), Jak inhibitor (13%), lenalidomide (4%), and prednisone (4%). At the time of this analysis, 78/91 patients (86%) were alive. When IWG-MRT criteria were applied to the PV/ET group, 38/58 (66%) of patients fulfilled criteria for diagnosis of post-PV/ET myelofibrosis (except for the 2+fibrosis requirement). Table 1 Patient characteristics UPN Age (yrs) Sex System Risk Activity Tx BRAFV600E (%) 1 56 F Multi High Inactive Yes 0 2 38 F Single High Inactive Yes 0 3 65 F Multi High Active Yes 2.59 4 48 M Single High Inactive Yes 0 5 41 F Single High Inactive Yes 0 6 28 M Multi High Inactive Yes 0 7 29 M Multi High Active No 1.00 8 47 F Multi High Active Yes 6.16 Discussion and Conclusion: PV and ET patients with WHO grade 1 marrow fibrosis manifest a phenotype that suggests progression to post-PV/ET myelofibrosis, and clinically overlap with PMF phenotype; however, these patients currently fail to meet 2008 IWG-MRT diagnostic criteria for this diagnosis on basis of sub-threshold fibrosis. MPN progression represents a biological spectrum and definitions of progression in ET/PV may benefit from other criteria not restricted by degree of fibrosis. Disclosures Mesa: Incyte, CTI, NS pharma, Gilead, Celgene: Research Funding.