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Purpose of review To summarize the recent literature related to female hemophilia A carriers with respect to prevalence in the population, the impact of baseline factor VIII levels and other influences on bleeding phenotype, and clinical management needs. Recent findings Many female hemophilia A carriers are at risk for abnormal bleeding, yet they are underrecognized by healthcare providers and their bleeding symptoms are underreported. Low FVIII levels are consistently associated with clinically significant bleeding and correlate well with skewed X chromosome inactivation (XCI). Most interestingly, bleeding tendency is also observed in some hemophilia A carriers with normal factor VIII levels and requires further investigation. Well controlled studies investigating peripartum and periprocedural FVIII levels and adequate hemostatic treatment are necessary to inform management guidelines. Summary Prevalence and bleeding tendency of hemophilia A carriers remain underreported, despite a significant proportion having low FVIII levels. Skewed XCI may explain low FVIII but does not explain the bleeding risk encountered in a larger proportion of hemophilia A carriers with random XCI and borderline/normal FVIII.

Purpose The cost of cancer therapies continues to increase, raising concerns of distributive justice and sustainability of our health-care system. We propose a simple set of cost effectiveness calculations using the concept of number needed to treat (NNT) to frame this debate in objective terms for practicing physicians and policy makers. We then apply this strategy to all monoclonal antibodies approved for adult hematology/oncology indications as of July 2015. Methods Monoclonal antibodies were identified from the “FDA Approved Drug Products”. Approved hematology/oncology indications for each antibody were extracted from package inserts. All comparative studies used to support each drug’s approval for each indication were analyzed. Overall survival (OS) was our preferred outcome measure. If OS data was not collected, the primary endpoint used in the trial was substituted. Average Wholesale Price was used to calculate the cost. Number Needed to Treat (NNT), “Incremental Cost” and “Cost Index” were calculated for each antibody and each disease indication. Results Forty-eight unique monoclonal antibodies were identified. Sixteen met inclusion/exclusion criteria. Forty-seven trials provided relevant comparative data. We report Overall Survival (OS), Progression Free Survival, and alternative endpoints for each trial. In aggregate, mean NNT for an OS advantage was 12 (range 5–25), mean “Incremental Cost” per improved OS was $788,876 (range $164,399-$2,469,012), and mean “Cost Index” per improved OS was $51,382/month (range $3245 - $205,751). Drug efficacy did not correlate with drug pricing. Conclusion The “common currency” of NNT provides a concise, clinically relevant approach for framing the debate between individual benefit and public health priorities. Some monoclonal antibodies for some hematology/oncology indications may not meet reasonable thresholds for widespread use.

Introduction: While Factor VIII (FVIII) activity correlates with phenotype in most Hemophilia A (HA) males, the study of rare individuals with discrepant bleeding phenotypes can provide insight into F8 genotype-bleeding phenotype relationships, refine HA classification and improve clinical management. We present an adult male subject who carries a F8 missense mutation, c.5999G>C (p.Gly2000Ala), but remarkably has had no bleeding despite numerous challenges, including multiple surgeries. To resolve genotype-phenotype discrepancy, we evaluated F8 transcripts and screened for additional gene variants by exome sequencing. Methods: We performed clinical laboratory assays including one-stage FVIII:C and chromogenic FVIII assays, FVIII antigen ELISA, VWF antigen and activity assays, and von Willebrand Disease (VWD) Type 2 Normandy binding activity assay. The F8 c.5999G>C mutation is proposed to affect F8 splicing, and result in a transcript that deletes exon 19. To evaluate F8 splice variants, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed using primers that distinguish FVIII isoforms. Samples were normalized relative to a housekeeping gene, GAPDH. Normalized relative fold expression for each primer pair was calculated by the 2−ΔΔCT Livak method. Whole exome sequencing was performed at 80X coverage. Sequencing reads were mapped to the GRCh37/hg19 reference genome with BWA-MEM, and high-quality variant calls were made using GATK4.0 with annotation based on refSeq 1.9, employing best practice recommendations. Results: Clinical assays confirmed reduced FVIII activity levels consistent with mild HA. By qRT-PCR, the F8 mutation results in a partial splicing defect. Exon 19 deleted transcripts predominate, but are likely not secreted. Indeed, the reduced levels of full-length F8 isoform closely mirror measured FVIII protein and activity levels. These findings explain FVIII levels, but to do not explain the absent phenotype. Exome sequencing analysis first confirmed the F8 mutation and excluded other genetic causes of FVIII deficiency. Additionally, we excluded thrombophilic mutations proposed to attenuate bleeding severity in HA, including Factor V Leiden (c.1601G>A, p. R534Q) and the c.*97G>A (p.G20210A) mutation in the F2 gene encoding prothrombin. To identify additional variants that may modify hemostasis, we then screened for non-pathogenic variants in 96 genes that are known to be mutated in bleeding disorders or that alter FVIII clearance or half-life. Of 352 single nucleotide variants (SNVs) in these genes, we prioritized 10 non-synonymous variants with annotated effects on hemostasis. Of these, four are associated with functional effects that would potentiate bleeding phenotype in coagulation factor deficiency. In contrast, five variants are associated with prothrombotic effects and are strong candidates for ameliorating bleeding. Of these, two non-pathogenic VWF variants, rs1063856 and rs7962217, have been shown to increase FVIII. Three other variants in F5 reside within the R2 haplotype. R2 has effects in the absence of Factor V Leiden and can increase thrombin generation and FVIII levels. Conclusion: The identification of multiple variants that are expected to attenuate bleeding suggests that a single gene variant is unlikely to ameliorate bleeding phenotype in this subject, particularly in the presence of additional variants that promote bleeding. These results suggest evaluation of non-pathogenic variants in non-F8 genes may further explain other cases of discrepant HA not resolved by clinical assays. While these new modulators of HA phenotype require functional confirmation, they provide new avenues for therapeutic development. Disclosures Eyster: Bayer: Other: research support; Baxalta: Other: research support; Shire: Other: research support; NovoNordisk: Other: research support; SPARK: Other: research support.

Introduction: Although FVIII activity (FVIII:C) correlates with phenotype in most Hemophilia A males, some have bleeding phenotypes milder than predicted by FVIII:C. Analysis of these individuals may provide additional insight into the relationship between F8 genotype and bleeding phenotype, identify additional factors that modulate FVIII, refine the classification of Hemophilia A and improve clinical management. We present a male subject who carries a c.5999G>C mutation in F8. This mutation has been reported in an individual with a severe bleeding phenotype in the EAHAD F8 Variant Database (www.factorviii-db.org). Our subject was serendipitously diagnosed at age 80, and has never had abnormal bleeding despite numerous challenges, including multiple dental extractions, adult circumcision, internal hemorrhoid ligation and cardiac catheterization. In an effort to resolve this genotype-phenotype discrepancy, we performed FVIII and von Willebrand Factor (VWF) assays, quantitated the extent of alternative splicing in F8, and screened for mutations in additional genes known to impact hemostasis. We validated a partial splicing defect that is consistent with mild Hemophilia A, but surprisingly cannot explain the lack of a bleeding phenotype. Methods: Peripheral blood was tested by one-stage FVIII:C and chromogenic FVIII assays, FVIII antigen ELISA, VWF antigen and activity assays, and von Willebrand Disease (VWD) Type 2 Normandy binding assay. To evaluate F8 splice variants, quantitative RT-PCR (qRT-PCR) was performed on RNA isolated from peripheral blood using primers that distinguish FVIII isoforms. Samples were tested in quadruplicate, with sample input normalized relative to GAPDH. Screening for exonic mutations in F8, F5, F2 and VWF genes was undertaken by Next Generation Sequencing (NGS). Results and Conclusions: In contrast to the previously reported severe c.5999G>C patient, this subject has reduced FVIII activity consistent with mild Hemophilia A measured by both FVIII activity assays. FVIII antigen assessment by ELISA gave similar results (0.35 IU/mL). To better understand FVIII:C levels in this individual, we sought to characterize F8 transcript isoforms. The c.5999G>C resides within the splice acceptor site of exon 19 and may result in two FVIII isoforms. One isoform produces a full-length FVIII containing a missense mutation (p.Gly2000Ala). The second isoform skips the 117 bp exon 19, but is predicted to retain an open reading frame; however, its location in the A3 domain likely disrupts secretion or function (Donadon et al., Haematologica 2018). The relative abundance of F8 variants evaluated by qRT-PCR demonstrated that despite a modest overall increase in F8 transcript relative to a normal control (1.6 fold higher expression of F8 at exon 18), the predominant isoform in this subject lacks exon 19, resulting in substantial depletion of the full-length isoform (0.3 relative to a normal control). These data indicate the full-length protein likely retains function, with transcript levels that explain residual FVIII activity. In an effort to explain absent bleeding phenotype, NGS was performed. The c.5999G>C F8 mutation was confirmed, while the thrombophilic Factor V Leiden and Prothrombin G20210A mutations were excluded. Sequencing also excluded mutations implicated in Type 2 Normandy VWD. Additional clinical testing may provide an explanation. VWF was elevated as indicated by VWF antigen and Ristocetin cofactor activity (>400%, >100%, respectively). Furthermore, VWF:FVIII binding activity by ELISA showed a higher than normal binding ratio (>1.42). VWF multimer analysis indicated normal distribution. Therefore, we propose elevated VWF abrogates this subject's bleeding phenotype. Altogether, our study expands our understanding of the functional consequences of this mutation by demonstrating that this mutation can result in FVIII levels predicting mild Hemophilia A. This case also underscores the complexities of predicting phenotype for mutations that result in partial splicing defects. Perhaps more intriguing is the lack of bleeding phenotype in this elderly individual with numerous hemostatic challenges, that might be related to increased VWF. These data support additional studies investigating the role of VWF in ameliorating bleeding risk in Hemophilia A. Disclosures No relevant conflicts of interest to declare.

Diffuse large B-cell non-Hodgkin lymphoma (DLBCL) is a disease of the elderly, but our current guidelines and treatment paradigms for this disease are based on studies that have mainly enrolled younger patients. Because the number of people living beyond the age of 80 increased by more than 250% between 1960 and 2000, and since it is expected that the population over the age of 75 will triple by 2030, understanding how these elderly patients should be treated is paramount to improving outcomes for this potentially curable lymphoma. In this review, we outline the scope of the problem; we define "the elderly" and identify challenges in assessing this patient population. We also summarize pivotal studies that have been conducted in these elderly patients and suggest an algorithm to aid clinicians in making treatment decisions when faced with DLBCL patients older than 80.

Background: Hemophilia A (HA) is an X-linked recessive disorder that affects males, whereas female carriers are presumed asymptomatic if Factor VIII activity levels (FVIII:C) fall within normal range. However, FVIII:C does not always correlate with bleeding phenotype, leading to an underappreciation of bleeding sequelae in females. Therefore, it is clinically important to identify HA carriers at higher bleeding risk. FVIII expression in HA carriers is influenced by X chromosome inactivation (XCI), a process that silences one X in XX females such that each cell has a random probability of inactivating either parental X. However, rare female carriers of X-linked disorders can be severely affected if XCI is skewed and the mutant X is preferentially active. How XCI skewing modulates bleeding in mild/moderate HA is less well understood. HA bleeding may be also affected by variants in factors influencing FVIII binding and clearance, including Von Willebrand Factor (VWF) and ABO blood type. To better understand HA carrier bleeding tendency, we analyzed a family that segregates a mild/moderate HA mutation (F8: c.2167G>A). Four carriers in this pedigree have FVIII:C that approach affected males, necessitating prophylaxis prior to surgical procedures. We hypothesized that bleeding in these carriers can be largely explained by XCI skewing, but additional variants may fine tune FVIII:C. Methodology: FVIII levels were assessed by one stage (FVIII:C) and chromogenic (FVIII:CR) assays. At least two plasma samples spanning >3 years from each female were tested in duplicate with each FVIII assay. To address XCI skewing, we performed methylation-based assays at the Androgen Receptor (AR) and Fragile X Mental Retardation 1 (FMR1) loci. At least three independent PBMC DNA samples from each female were evaluated. Additionally, we screened VWF regions known to influence FVIII:C (exons 18-20, 24-27). Results: For each female, results between XCI assays were indistinguishable (r2 = 0.99). Two of four females had pronounced skewing (≥80:20); a third had measurable skewing (67:33). Importantly, all three predominantly expressed the mutant paternal allele. Familial XCI skewing argues for a genetic cause. However, XIST, the major regulator of XCI, lacked promoter alterations. Importantly, there was linear correlation between XCI skewing and FVIII:C measured by FVIII:C or FVIII:CR assays (r2 = 0.77 and 0.83, respectively). One female with random XCI, had FVIII:C considered hemostatic (median 51%, range 43-67), whereas the other females with skewed XCI had levels Conclusions: Our results indicate that HA carrier bleeding phenotypes are multifaceted, and the major determinant of FVIII:C is XCI. These results also suggest that even moderate XCI skewing could influence clinical bleeding in HA carriers. However, random XCI in one female explains FVIII:C but does not fully negate bleeding tendency, emphasizing the complexity of carrier phenotype. These findings provide justification for an expanded study of carriers in unrelated pedigrees using a comprehensive approach to include XCI assays. Disclosures No relevant conflicts of interest to declare.

Background: Hemophilia A (HA) is an X-linked disorder that primarily affects males, although female carriers can exhibit bleeding phenotypes. Factor VIII activity levels (FVIII:C) in XX females are influenced by X chromosome inactivation (XCI), a process that silences each parental X in a proportion of cells. XCI skewing can decrease FVIII expression by preferentially inactivating the normal X chromosome. FVIII:C is further modulated by factors such as ABO blood groups and von Willebrand factor (VWF). The D'/D3 domain of VWF binds circulating FVIII protein, preventing proteolytic degradation. In type 2 Normandy von Willebrand disease (2N VWD), D'/D3 mutations decrease affinity to FVIII and result in bleeding events similar to mild/moderate HA. Variants in VWF also affect the pharmacokinetics of recombinant FVIII. Current clinical screening tests detect the 3 VWF mutations responsible for >90% of 2N, but report variants not directly responsible for 2N as clinically benign. However, common polymorphisms are known to affect FVIII:C in normal individuals. Therefore, a better understanding of how specific alterations in VWF modulate HA phenotype is necessary to interpret clinical presentation and refine management with factor concentrates. This is particularly important in HA individuals carrying mild/moderate mutations. To evaluate VWF variants in HA carriers, we focused on an extended pedigree that includes four obligate carriers from a family with mild/moderate HA (FVIII: p.Ala723Thr). FVIII:C varied and largely correlated with XCI skewing. Nevertheless, the FVIII:VWF interaction prompted us to identify VWF gene variants that could further modulate FVIII:C and contribute to bleeding in this family. Methods: To identify D'/D3 VWF variants that impact FVIII binding, primers were designed to amplify exons 17-20 and 24-27 on chromosome 12. A chromosome 22 pseudogene, with 97% identity to VWF exons 24-34, complicated primer design. Primers specific to VWF were selected by targeting regions that differed from the pseudogene and were verified by digestion with a restriction enzyme unique to each chromosome 12 exon. The PCR products were amplified and sequenced from the four female carriers and a control male relative. Results: After excluding the three most common mutations responsible for 2N, seven other variants were identified. Four of these were intronic polymorphisms and a synonymous variant at p.Asn1138 not associated with VWD and presumed to be clinically benign. All but one of these have been described in normal individuals. Two females were heterozygous for missense variant rs1063856 (p.Thr789Ala) and synonymous polymorphism rs1063857 (p.Tyr795=) that are in linkage disequilibrium and are likely to impact FVIII:C and VWF antigen (VWF:Ag) levels. These common variants, found in up to 36% of Caucasians and 58% of African Americans, are reported to increase VWF:Ag and FVIII:C jn heterozygotes (9 IU/dL and 7 IU/dL respectively). Neither ABO blood groups nor XCI skewing could fully explain the differences in FVIII:C activity observed with this variant. Conclusions: We propose that VWF variants rs1063856/rs1063857 may contribute to FVIII:C differences between two females in the pedigree with similar XCI skewing. We conclude that consideration of VWF variants is important for fully understanding bleeding phenotype and treatment responses in female carriers and males in families with mild/moderate HA. These findings support the need for expanded studies into the role of FVIII and VWF variant interactions in additional unrelated HA individuals. Disclosures No relevant conflicts of interest to declare.

6598 Background: Monoclonal antibodies (mabs) have great clinical potential for individual patients, but also substantial cost to society. We propose a very simple, transparent calculation to frame...

Abstract 2728 Background: TCLs are uncommon malignancies consisting of heterogeneous pathologic subtypes and outcomes. Despite development of prognostic models, there is little data of outcomes in large cohorts examining the impact of frontline therapy and the role of consolidative stem cell transplantation (SCT). Methods: We performed a multi-center retrospective analysis of a large cohort of newly diagnosed mature TCLs (non-cutaneous) from 2000–2010 across 9 U.S. academic centers. We examined detailed information regarding patient characteristics and treatment(s) received. Further, we determined prognostic factors for associations with survival in univariate analysis and multivariate Cox regression proportional models. Results: Among 402 cases of mature TCL, 341 had complete treatment and follow-up data. This included 107 cases of peripheral TCL (PTCL NOS), 89 anaplastic large cell lymphoma (ALCL), 77 angioimmunoblastic TCL (AITL), 23 NK/TCL, 20 acute t-cell leukemia/lymphoma (ATLL), 10 enteropathy-associated TCL (EATCL), 7 subcutaneous panniculitis-like TCL (SCPTCL), 5 hepatosplenic TCL (HSL), and 4 transformed CTCL (t-CTCL) cases. 60% of pts were men and the median age was 62 years (range 18–95). At initial diagnosis, performance status was 2–4 in 36%, B symptoms in 47%, elevated LDH in 55%, anemia in 64%, and hypoalbuminemia in 46% at baseline. 74% of pts had advanced-stage disease, 29% had bone marrow involvement, 52% had other (non-marrow) extranodal sites, and only 9% had bulky disease >7cm. Twenty-three pts received only palliative therapy all of whom survived Conclusions: In this large US cohort of TCL, response, PFS, and OS compared favorably with historical controls. Further, we documented that NK/TCL, AITL, and ALCL (ALK+ and negative) were all associated with improved OS vs PTCL NOS. On multivariable analysis, limited-stage disease was the predominant predictive factor for survival. Additionally, consolidative SCT was associated with improved PFS and OS, however this benefit appeared to be nullified after controlling for initial response. Disclosures: No relevant conflicts of interest to declare.

127 Background: SOR is an oral multi kinase inhibitor that promotes apoptosis through downstream pathways that can be deregulated in CRPC leading to chemotherapy resistance. We hypothesized that SOR Could overcome chemotherapy resistance in non-responders or in those who progress shortly after stopping chemotherapy. Methods: Eligible pts were those who progressed while receiving chemotherapy [docetaxel (D) or mitoxantrone (M)] or within 12 weeks from stopping it. Pts were then continued or resumed on their last chemotherapy with the addition of SOR at 400 mg PO BID. Pts were allowed a maximum of 6 cycles of chemotherapy +SOR followed by SOR as monotherapy until progression. Primary end point: Safety of SOR+ chemotherapy. Secondary end points: Toxicity, time to progression (TTP). And responses (biochemical and radiographic) Results: Twenty-two pts were enrolled; 21 evaluable (73% Gleason ≥ 7). Median age was 68 (59-83). Median PSA was 142 ng/dl (13.6-9,584). Median time from last chemotherapy to SOR was 4 weeks. Visceral and bone disease was present in 64%. D was given in 16 pts while M in 6. Ten pts (45%) showed biochemical response (18% with >50% PSA decline). Despite progression before being on study, 16 pts (76%) achieved SD after starting SOR for a median duration of 6 months (4-12). The combination of SOR with either chemotherapy agent proved safe. Main grade 3/4 non-hematologic toxicities: Fatigue 7 (32%), 4 (18%) hand/foot syndrome, hypocalcemia and hyperglycemia in 2 pts (9%) each. Grade 3/4 leukopenia was seen in 7 (31%), neutropenia in 6 (27%), and thrombocytopenia in 2 (9%). Dose reduction of SOR occurred at least once in 15 pts (68%). Major reasons are hand/foot syndrome (22%), fatigue (22%), rash (13%), and neutropenia (9%). With a median follow-up of 19 months (3-46), 5 pts (23%) remain alive for a median OS of 8 months. TTP by PSA was 3 months (2-6) and TTP by imaging and/or clinically was 6 months (2-12). Median number of treatment cycles given was 6 (1-10). Conclusions: SOR can safely be combined with chemotherapy. SOR overcomes chemotherapy-resistance and shows biochemical and radiographic stability in this refractory pt population.