Citations

Abstract Purpose: We recently reported a 17.5% objective RECIST 1.1 response rate in a phase II study of pembrolizumab in patients with advanced sarcoma (SARC028). The majority of responses occurred in undifferentiated pleomorphic sarcoma (UPS) and dedifferentiated liposarcoma (DDLPS). We sought to determine whether we can identify immune features that correlate with clinical outcomes from tumor tissues obtained pre- and on-treatment. Patients and Methods: Pretreatment (n = 78) and 8-week on-treatment (n = 68) tumor biopsies were stained for PD-L1 and multiplex immunofluorescence panels. The density of positive cells was quantified to determine associations with anti–PD-1 response. Results: Patients that responded to pembrolizumab were more likely to have higher densities of activated T cells (CD8+ CD3+ PD-1+) and increased percentage of tumor-associated macrophages (TAM) expressing PD-L1 pre-treatment compared with non-responders. Pre-treatment tumors from responders also exhibited higher densities of effector memory cytotoxic T cells and regulatory T cells compared with non-responders. In addition, higher density of cytotoxic tumor-infiltrating T cells at baseline correlated with a better progression-free survival (PFS). Conclusions: We show that quantitative assessments of CD8+ CD3+ PD-1+ T cells, percentage of TAMs expressing PD-L1, and other T-cell densities correlate with sarcoma response to pembrolizumab and improved PFS. Our findings support that multiple cell types present at the start of treatment may enhance tumor regression following anti–PD-1 therapy in specific advanced sarcomas. Efforts to confirm the activity of pembrolizumab in an expansion cohort of patients with UPS/DDLPS are underway.

126 Background: Pharmacogenomics (PGx) is a developing field in individualized medicine concerned with understanding genetic polymorphisms that may explain inter-individual variation in drug efficacy and toxicity. Understanding these polymorphisms is a key tool in guiding clinician’s selection and dosing of specific medications to optimally manage patient symptoms. Common pharmacogenes that impact analgesic prescribing include: CYP2D6, OPRM1, and COMT; for mood disorders: CYP2C19. This cross-sectional study explored the activity of pharmacogenes of clinical significance in palliative medicine with either Level 1 or 2 evidence. Methods: We performed PGx testing on 50 new referrals to the palliative medicine clinic with an active malignancy. Each patient underwent PGx testing with clinical pharmacist review and interpretation prior to their initial office appointment. Results: In our cohort 54% were men and the mean age was 64.7 (24-87). The average number of medications, medication allergies, and creatinine clearance were 10.5 (1-22), 1.3 (0-13), and 78.4 (31-120), respectively. Among the pharmacogenes impacting opiate and antiemetic prescribing, 14% (7/50) of patients were poor metabolizers of CYP2D6 and 8% (4/50) were rapid or ultra-rapid metabolizers. Another 60% (30/50) showed intermediate metabolism which would impact initial dosing. Poor metabolism of COMT or OPRM1 was seen in 8% (4/50) with another 36% (18/50) demonstrating rapid metabolism. Activity for the pharmacogene CYP2C19, which impacts many psychotropics, revealed 32% (16/50) rapid or ultra-rapid metabolizers and no poor metabolizers. Overall, 66% (33/50) of patients had pharmacogene activity suggestive of significant clinical impact necessitating either drug avoidance due to toxicity risks or substantial dose adjustment to be efficacious. Conclusions: Polymorphisms impacting pharmacotherapy were common in our cohort. Patients with difficult-to-control symptoms or multiple medication toxicities can utilize PGx testing as a guide to symptom relief. As PGx technology becomes readily accessible and economical, opportunities for patients to have precision genomic information guide healthcare decisions is expected to increase.

Abstract Introduction DLBCL is the most common lymphoid neoplasm in adults (Swerdlow 2016). While durable CRs are achieved in approximately 70% of patients (pts) with frontline RCHOP therapy (Pfreundschuh 2008), pts with high-risk features often experience disease resistance or relapse. In Part 1 of an ongoing study, pts with high-intermediate or high risk DLBCL by international prognostic index (IPI) scores, regardless of CD30 expression by IHC, were treated with 1.2 or 1.8 mg/kg brentuximab vedotin (BV) combined with RCHOP. After 3 of the first 10 pts treated at 1.8 mg/kg BV+RCHOP developed Grade 3 peripheral neuropathy (per Standardized MedDRA Query [SMQ]), all pts enrolled subsequently received treatment with 1.2 mg/kg BV+RCHOP. Following completion of enrollment in Part 1, the protocol was amended to enroll a non-randomized portion of the study (Part 2) evaluating the safety and efficacy of 1.8 mg/kg BV+RCHP (Yasenchak 2015), followed by an open-label, randomized portion comparing BV+RCHP to RCHOP (Part 3). Initial results from Part 2 and updated results from Part 1 are reported here. Methods For Part 2 of the study, pts with CD30-expressing high-intermediate and high-risk DLBCL were treated with up to 6 cycles of 1.8 mg/kg BV+RCHP (NCT01925612). Key inclusion criteria were CD30 expression by IHC performed by a local pathology lab and standard IPI scores of 3-5 or age-adjusted IPI (aaIPI) scores of 2-3 (high-intermediate/high risk). CD30 expression was confirmed by a central pathology lab, although CD30 expression by local pathology lab was required for eligibility. Disease response was evaluated with PET/CT per Cheson 2007. Results At the time of analysis for this ongoing study, 11 pts in Part 2 were treated with BV+RCHP (7 male, 4 female; 22-78 yrs). Of these pts, 9 had high-intermediate risk (IPI 3, aaIPI 2) and 2 had high risk disease (IPI 4-5, aaIPI 3), 6 had Stage IV disease, and 6 had an ECOG score of 2. At the end of treatment, the overall response rate was 91% (9 CR, 1 PR); 1 pt had PD after Cycle 4. The most frequent (>20%) treatment-emergent adverse events (AEs) were alopecia and nausea (73% each); fatigue (64%); constipation and peripheral sensory neuropathy (55% each); neutropenia and throat irritation (36% each); and chills, diarrhea, headache, and stomatitis (27% each). Grade 3 or 4 AEs occurred in 8 pts and 5 pts had serious AEs, which included febrile neutropenia, bacteremia, nausea, pneumocystis jiroveci pneumonia, pulmonary embolism, and vomiting. Peripheral sensory neuropathy occurred in 6 pts and all were Grade 1 or 2 events; no peripheral motor neuropathy AEs were reported. No AEs were fatal or led to discontinuation. One pt discontinued treatment after Cycle 4 due to disease progression. For the first 51 pts in Part 1, the progression-free survival (PFS) at 18 months for pts with CD30 expression (25 pts) or without detectable CD30 expression (24 pts) by IHC was 79% (95% CI: 57%, 91%) versus 58% (95% CI: 36%, 75%), respectively. Overall survival for pts was 92% (95% CI: 71%, 98%) versus 71% (95% CI: 48%, 85%), respectively. Ten pts had pre-existing peripheral neuropathy (per SMQ) at study entry. Treatment-emergent peripheral neuropathy (per SMQ) was observed in 75% of pts (38/51) who received BV+RCHOP; 55% of these pts (21/38) had resolution of all or some peripheral neuropathy events. Conclusions 1.8 mg/kg BV+RCHP is active as frontline treatment in CD30-expressing, high-intermediate/high risk DLBCL. When combined with RCHP, 1.8 mg/kg BV appears to be well-tolerated. The PFS and OS for pts with CD30-expression who received BV+RCHOP appear promising. The study is currently ongoing in pts with CD30-expressing high-intermediate/high risk DLBCL to assess the safety and activity of 1.8 mg/kg BV+RCHP versus standard RCHOP. Disclosures Halwani: Bristol Myers-Squibb: Research Funding; Kyowa Hakko Kirin: Research Funding; Takeda: Research Funding; Genentech: Research Funding; AbbVie: Consultancy, Other: Travel Expenses, Research Funding; Seattle Genetics: Consultancy, Research Funding; Immune Design: Research Funding; Miragen: Research Funding; Pharmacyclics: Consultancy; Amgen: Research Funding. Yasenchak:Seattle Genetics: Research Funding. Farber:Seattle Genetics: Research Funding. Burke:Pfizer: Consultancy; Janssen: Consultancy; Incyte: Consultancy; TG Therapeutics: Other: Travel Expenses; Millenium: Consultancy. Fayad:Seattle Genetics: Consultancy, Research Funding. Holkova:Seattle Genetics: Research Funding. Knapp:Insys Therapeutics, Inc.: Consultancy, Other: Travel, Accommodations, Expenses; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Other: Travel, Accommodations, Expenses, Research Funding. Kolibaba:Gilead: Consultancy, Research Funding; Celgene: Research Funding; TG Therapeutics: Research Funding; Takeda Pharmaceuticals International Co.: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; janssen: Research Funding; GSK: Research Funding; Genentech: Research Funding; Acerta: Research Funding. Patel-Donnelly:Seattle Genetics: Research Funding. Yimer:Ariad Pharmaceuticals: Consultancy; Biotheranostics: Consultancy; Bluebird Bio: Equity Ownership; Kite Pharma: Equity Ownership; Clovis Oncology: Equity Ownership; Juno Therpeutics: Equity Ownership; Seattle Genetics: Research Funding. Smith:Celgene: Consultancy, Speakers Bureau; Seattle Genetics: Research Funding. Levy:Janssen: Speakers Bureau; Amgen: Speakers Bureau; Takeda Pharmaceuticals International Co.: Speakers Bureau; Seattle Genetics: Research Funding; Actinium Pharmaceuticals, Inc.: Research Funding. Seetharam:Seattle Genetics: Research Funding. Belada:Seattle Genetics: Research Funding. Brooks:Seattle Genetics: Research Funding. Kingsley:Gilead: Equity Ownership; Pharmacyclics LLC, an AbbVie Company: Equity Ownership. Wagner-Johnston:Seattle Genetics: Research Funding. Ruffner:Forma Therapeutics: Consultancy; Sydnax: Consultancy; Seattle Genetics: Employment, Equity Ownership; Array Biopharma: Employment; Medivation: Employment. Bartlett:Gilead: Consultancy.

Abstract Introduction: Relapse is the primary cause of death after reduced intensity conditioning (RIC) hematopoietic cell transplantation (HCT). Documented responses have been reported after combination chemotherapy, hypomethylating agents, donor lymphocyte infusions, and second transplants. For patients with early relapse after RIC HCT while still on immunosuppression (IS), IS taper alone may induce significant graft-versus-tumor (GVT) activity. We describe the clinical characteristics and subsequent course of 48 patients with disease recurrence that responsed to IS taper alone without any additional chemotherapy, radiation, or donor lymphocyte infusion. Methods: We reviewed medical records of all patients with frank histologic or radiographic evidence of relapse (n=477) and those with impending relapse defined by development of cytopenias with a fall in donor derived hematopoietic cell chimerism (n=87) within one year of allogeneic RIC HCT who were on IS at time of relapse between January 1, 2004 and December 31, 2013 at Dana Farber Cancer Institute/Brigham and Women's Hospital. Complete response after IS taper was defined as complete recovery of peripheral blood counts, bone marrow biopsy with absence of disease, negative radiologic imaging, or chimerism recovery to above 90 percent. Partial response was defined as improvement in disease burden in bone marrow or by imaging. Survival probabilities were calculated using the Kaplan Meier method. Results: Forty-eight patients (37 male, 11 female) who relapsed within one year of HCT responded to IS taper alone. Of these, 14 had impending relapse and 34 had frank relapse at time of IS taper. The median age of patients was 62 years at time of transplant. The most frequent indication for transplant was MDS (n=14) followed by AML (n=11), non-Hodgkin's lymphoma (n=8), CLL (n=6), Hodgkin's disease (n=4), CML (n=3) and multiple myeloma (n= 2). At time of transplant, 9 patients had standard risk disease and 39 had high risk disease. All patients except one underwent conditioning with busulfan (≤ 6.4 mg/kg) and fludarabine. Five patients had graft versus host disease (GVHD) prior to relapse. The median time to frank or impending relapse was 105 days (range 57-360) after HCT. The median interval between starting and completing IS taper was 30 days (range 0-251), but 13 patients could not come off IS completely due to GVHD. The median time to documented response after initiation of IS taper was 77 days (range 14-189). Thirty-five patients had a complete response and the remaining 13 patients had a partial response. Nine patients subsequently relapsed late after initial response to IS taper at a median time of 2.38 years (range 0.88-3.95). Forty-five of the 48 patients developed or had a flare of previous GVHD as a consequence of IS taper. Of these, 26 patients had grade II-IV acute GVHD and 19 had chronic GVHD. The median time to developing GVHD after starting IS taper was 39 days (range 7-261 days). Twenty-five patients died during follow-up (10 from GVHD, 6 from disease, 7 from infection, 1 from congestive heart failure and 1 unknown). The median follow-up time among survivors was 4 years (range 1.6, 9.4). The median overall survival (OS) time from IS taper was 4.78 years (95% CI 2.93-7.35, see figure). The 4 year overall survival was 56%. There was no difference in survival for those with frank or impending relapse. Conclusion: Immunosuppression taper alone in patients who relapse early after RIC HCT can produce durable remissions but is almost always associated with development of GVHD. Understanding the clinical, molecular and immunologic characteristics of underlying disease will allow us to better predict who will respond to this manipulation. When feasible, this strategy should be given sufficient time to allow for a GVT response to develop in order to possibly avoid the adverse effects of more aggressive therapies. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Abstract BACKGROUND Treatment options and prognosis are limited for patients with high grade glioma (pwHGG), underscoring the importance of patient and caregiver understanding to prioritize goals of care and quality of life (QOL). Although addressed by multiple providers, patients and caregivers may experience discordance in understanding the prognosis. This may be related to patient/caregiver perception, cognitive decline as a result of the tumor and/or treatment, or failure by the clinician to clearly articulate this information under emotional circumstances. AIMS: To evaluate the longitudinal perception of prognosis of patients compared to their caregivers and their providers during the adjuvant treatment of newly diagnosed HGG. METHODS After IRB approval, 16 pwHGG, their caregivers and their providers reported an overall survival estimate at each monthly visit during adjuvant treatment, as part of a larger survey. Options included “weeks,” “weeks to several months,” “several months to years,” “indefinite number of years”, or “I do not wish to answer.” RESULTS Seven of the sixteen patient/caregiver clusters have completed the appropriate duration of the study with the remaining completing in November. The perception of the patient differs from the caregiver at almost each visit. Regardless of the counseling provided by provider, the perception of both tends to change at each visit and can vary from dismal to overtly optimistic. There does not appear to be discrepancy between the neuro-oncology and palliative care provider’s perception of prognosis. CONCLUSION Newly diagnosed pwHGG and caregivers vary in their perception of prognosis, deviating not only from each other but also differing at each visit throughout the course of their illness. The providers’ perception appeared to remain consistent but often varied from that of the patient and caregiver. Providers need to be aware that prognostic understanding appears to fluctuate throughout the course of illness and cannot be clarified via a single discussion.

Abstract BACKGROUND Early involvement of palliative care (PC) in patients with metastatic cancer has been associated with improved quality of life (QOL). Patients with high grade glioma (pwHGG) and their caregivers have unique needs such that similar results are anticipated in this population but cannot be extrapolated. Recognizing that pwHGG often require a caregiver early in the course of disease, this patient population also experiences significant personal and caregiver distress that has been given limited attention and resources. AIM: To assess the feasibility of implementation of a novel patient reported outcomes (PRO) quality of life (QOL) tool administered by smart device in routine office visit (OV) and early integration of palliative care (PC) for pwHGG and their caregivers to improve QOL for both. DESIGN: Prospective, single-center cluster-randomized pilot conducted for 6 months during completion of adjuvant therapy for newly diagnosed high grade glioma. After informed consent was obtained, 15 pwHGG and their caregivers were randomized to: routine OV with basic QOL survey; OV with PROQOL; or PC consultation, in addition to OV with PROQOL. RESULTS Two elderly patients with declining performance status transitioned to hospice after initial visit, and one moved out of state prior to adjuvant visits. Thus far 5/15 patients/caregivers have successfully completed the pilot with the 6 remaining participants due to complete in November 2019. DISCUSSION The PROQOL appears to be easily integrated into OV without significant patient, caregiver, or provider burden. Providers confirmed utility in prioritizing symptoms and concerns. Thus far, it appears that patients (and caregivers) appeared to benefit from the PROQOL and PC support as evidenced by longitudinal improvement in QOL scores over the control group. CONCLUSIONS A unique PROQOL tool and early PC can be easily integrated into practice, and may improve the QOL of pwHGG and their caregivers.

Abstract Background Even though obstructive sleep apnea (OSA) is strongly associated with atrial fibrillation (AF), the use of traditional OSA scoring by apnea hypopnea index (AHI) did not result in improved arrhythmia outcomes in recent randomized trials. Longer OSA episodes lead to stronger pro-arrhythmic changes, and whether very long OSA episodes are more prevalent in AF patients remains unknown. Purpose We hypothesized that AF patients with mild-moderate OSA manifest greater percentage of long (>20s), very long (>30s), and extremely long (>40s) OSA episodes, compared to control OSA patients matched to AHI, age and sex. Methods From patients studied with diagnostic polysomnography in our laboratory between 2016 and 2018, we selected 22 patients with mild-moderate untreated OSA of which 11 patients had history of paroxysmal AF and 11 patients did not have any cardiac history. The length, oxygen desaturation, and relationship to neighboring events was manually re-measured in all recorded apnea and hypopnea events. Results In the 22 included patients (age 62.5±9.1 years, AHI 12.8±6.1, 40% female) we recorded 1021 apneas: 508 in the AF group and 513 in the control group. AF patients had longer apneas compared to the patients without AF history (mean length 28.7±11.7s vs. 23.3±9.9s; p<0.0001). The proportion of apneas that were long (>20s), very long (>30s), and extremely long (>40s) was greater in the AF group as compared to the control (p=0.0039, p=0.0215, p=0.0104, respectively; see figure). The acute oxygen saturation drops (>2%) during apneas were comparable between the AF group and control groups (p=0.13), but the long (>20s) apneas were prone to greater oxygen desaturations. Length of Apneas Conclusions While traditional scoring of OSA focuses on episodes lasting >10s, our data newly show that longer durations of OSA events are particularly prevalent in AF patients. These results, combined with recent mechanistic studies showing that longer apneas exert greater pro-arrhythmic effect on atrial conduction, suggest that novel scoring of OSA placing more weight on longer apneas should be explored, especially when screening and titrating OSA therapy in patients at risk of AF.

Abstract Introduction: Allogeneic hematopoietic stem cell transplantation (HCT) is the only curative therapy for myelofibrosis (MF). Consideration of HCT is recommended by international working groups and national guidelines for MF patients (pts) age <70 with intermediate-1 with adverse indicators, intermediate-2 or high-risk disease by the Dynamic International Prognostic Scoring System (DIPSS) for MF- a recommendation made in the absence of clear data indicating the optimal timing of HCT for MF. In this large multicenter retrospective study, we analyze overall survival in MF pts treated with and without HCT. Methods: Disease characteristics, treatments, and outcome data from MF pts receiving non-transplant therapy at 14 US academic medical centers between 2000-2014 were retrospectively collected. MF pts who underwent HCT were identified from the Center for International Blood and Marrow Transplant Research (CIBMTR). The Cox proportional hazards model was used. The reference time point (time zero) was time of referral for the non-transplant (non-HCT) arm and the time of transplant for the HCT arm. The main effect variable (HCT vs. non-HCT) violated the proportionality assumption where comparing to non-HCT, mortality was higher with HCT in early time period from time zero but then was lower in late time period; therefore, the comparison is presented as early time period and late time period. The Cox model identified 14 months from time zero as the ideal cut point to define early and late time periods. The proportionality assumption is satisfied within each of these two periods. Results: A total of 1377 and 551 pts were included in the non-HCT and HCT arms, respectively (Table 1). In the overall cohort, survival was higher with non-HCT vs. HCT in early time period (relative risk [RR]: 0.34, P< .0001, Figure 1D), but in late time period survival was lower with non-HCT vs. HCT (RR: 2.37, P< 0.001) (Table 2). In the DIPSS low-risk MF group, while survival was higher with non-HCT vs. HCT in the early time period (RR: 0.19, P=0.007, Figure 1A), survival was lower with non-HCT in the late time period, but the latter did not reach statistical significance (RR: 1.45, P=0.39). In the DIPSS intermediate-1 risk group, a survival advantage was present with non-HCT treatments vs. HCT in the early time period (RR: 0.27, P < .0001, Figure 1B), however survival was lower with non-HCT in the late time period (RR: 3.13, P < .0001). Similarly, in those with DIPSS intermediate-2 and high-risk MF, survival advantage was observed with non-HCT in the early time period (RR: 0.41, P< .0001, Figure IC), but survival was lower with non-HCT in the late time period (RR: 2.82, P < .0001). Conclusion: A long-term survival advantage with transplant was observed for pts with intermediate-1 or higher risk MF, but at the cost of potential early mortality. The magnitude of benefit increased as DIPSS risk score increased. Although this retrospective study has limitations, the results have an impact on clinical practice by suggesting that transplantation could be considered earlier in the disease course and supports the recommendation for consideration of HCT in the setting of intermediate-1 risk MF. Disclosures Gowin: Incyte: Consultancy, Other: Scientific Advisory Board, Speakers Bureau. Verstovsek:Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Incyte: Consultancy; Italfarmaco: Membership on an entity's Board of Directors or advisory committees. Ali:Incyte Corporation: Membership on an entity's Board of Directors or advisory committees. Gupta:Novartis: Consultancy, Honoraria, Research Funding; Incyte: Research Funding. Gerds:Celgene: Consultancy; Apexx Oncology: Consultancy; CTI Biopharma: Consultancy; Incyte: Consultancy.

Abstract Abstract 2877 FLC assay measures circulating unbound k and l light chains and is of diagnostic and prognostic value in plasma cell disorders. Normalization of FLC ratio is considered a higher level of complete response (CR) in MM but this has not been well validated prospectively. HLC is a novel antibody based assay that targets the unique junctional epitopes between the heavy chain and light chain constant regions of intact immunoglobulin (Ig) molecules. It separately measures in pairs the light chain types of each immunoglobulin class generating ratios of monoclonal Ig/background polyclonal Ig concentrations (i.e IgGκ/IgGλ, IgAκ/IgAλ and IgMκ/IgMλ); potentially simplifying assessment of monoclonal protein response. To assess the prognostic impact of these assays and to correlate them with electrophoretic/immunofixation (SPE/IFE) assessment, we analyzed 497 stored serum samples from patients enrolled in the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0102 clinical trial, sponsored by the NHLBI and NCI, of tandem autologous (autoHCT) vs. tandem autoHCT- allogeneic (alloHCT). Samples were collected prior to the first autoHCT and analyzed for FLC (Freelite™) and HLC (Hevylite™) at The Binding Site, UK. Corresponding disease status determination was centrally performed by an expert data review committee using uniform response criteria and correlated with FLC and HLC results. HLC remission was defined as normalization of composite heavy and light chain ratios across all 3 measured heavy/light chain pairs or the normalization of clonal isotype with normal ratios of uninvolved pairs. The demographics of 497 patients with HLC/FLC samples at baseline were concordant with the main study and showed similar patient proportions from the 2 study arms. Of the 211 pts with baseline SPE response better than or equal to a very good partial response (>VGPR), 188 also had an HLC remission (Sensitivity=89%). Comparison of the HLC remission with the >VGPR disease state also identified a specificity of 52%, positive predictive value (PPV) of 58% and a negative predictive value (NPV) of 87%. Similarly, all 56 patients in complete remission (CR) by SPE/IFE were in HLC remission. Compared with conventional CR assessment, sensitivity of HLC remission was 100%, specificity 39%, PPV and NPV values of 17% and 100% respectively. FLC remission correlated with >VGPR disease state had a sensitivity of 47%, specificity of 81% and a PPV and NPV of 64% and 67% respectively. Multivariate models for post transplant progression free survival (PFS) indicated that baseline disease response (>VGPR vs. partial remission (PR) or<PR) was associated with longer PFS. Adjusted models including baseline response, myeloma stage and study arm were used to compare the predictive utility of HLC and FLC assays. There was a lower risk of treatment failure (HR 0.74, p=0.02) and superior PFS for patients who achieved an HLC remission. When stratified by baseline disease response states, there was no additional prognostic impact for HLC remissions on PFS. Normalization of FLC ratio among patients with >VGPR disease state did not impact PFS (HR 0.96, p=0.83). Abnormal HLC after induction therapy has a high negative predictive value (100%) for identifying patients not achieving CR by uniform response criteria and is also associated with shorter PFS after transplant. FLC ratio normalization had no impact suggesting that stringent CR criteria may need further validation. Disclosures: Krishnan: Celgene: Speakers Bureau; Millenium: Speakers Bureau. Alvi:the binding site: Employment. Harding:The Binding Site Group Ltd: Employment. Maloney:Cellgene: Consultancy.

Abstract Five cases of erythroleukemia of the acute or incomplete variety form the basis of this report. Four of the patients were women. The ages of these five patients ranged from 19 to 73 years at time of admission to the Mayo Clinic. Studies were made on the blood and peripheral marrow for varying periods throughout the course of the disease. All five patients had anemia and extreme immaturity of the erythrocytes in the peripheral blood and bone marrow. Leukopenia was eventually present in four cases as was thrombopenia. Splenectomy was performed on one patient. One patient lived six years after the condition developed, two died within thirteen months of the time of diagnosis, one was not followed, and the fifth was still living at last report. Relatively few cases of erythroleukemia have been reported in the literature and most of those reported have been cases of the chronic variety. The erythrocytic picture in the chronic variety differs from that in the acute variety. In the acute type acute erythremia is associated with leukemia and in the chronic type polycythemia is associated with it. Either the erythrocytic abnormality or the leukocytic may appear first. Our studies and those reported in the literature suggest excessive activity of the blast cell in two directions.