ALBERT

Description: Postmenopausal women have an increased risk of cardiovascular disease, and heart disease is the leading cause of death in postmenopausal American women. Conventional hormone replacement therapy has been shown to result in an increase in thrombotic events in large prospective clinical trials including HERS I, and the recently halted Women’s Health Initiative. One possible mechanism for this observed increase is the unfavorable net effects of conjugated equine estrogens and medroxyprogesterone acetate on the hemostatic balance and inflammatory factors. An estimated 50 million American women are peri or postmenopausal and clinical therapies for menopausal symptoms remain a significant challenge in light of the known thrombotic risks. In this prospective blinded study, we examined the short-term effect of topical progesterone cream on menopausal symptom relief in 30 healthy postmenopausal women. Potential adverse effects of topical progesterone on hemostatic and inflammatory factors and cortisol levels were also examined. Subjects were randomized to first receive either 20 mg of topical progesterone cream or placebo cream for 4 weeks. Following a subsequent 4-week washout period, subjects were crossed over to either placebo cream or active drug for an additional 4-week period. In each case, progesterone and cortisol levels were monitored by salivary sampling. Baseline values, 4-week follow-up values and end-of-study values were also obtained for the Greene Climacteric Scale, total factor VII:C, factor VIIa, factor V, fibrinogen, antithrombin, PAI-1, CRP, TNFα, and IL-6. For subjects receiving 20 mg of topical progesterone cream for 4 weeks, Greene Climacteric Scale scores were consistently and significantly improved (decreased) over baseline, demonstrating significant relief from menopausal symptoms. In addition, in a subpopulation of hypercortisolemic women, topical progesterone was associated with a favorable decrease in nocturnal cortisol. Surprisingly, and in sharp contrast to earlier studies with conventional hormone replacement therapy, topical progesterone had no effect on any of the hemostatic components examined: total factor VII:C, factor VIIa, factor V, fibrinogen, antithrombin, and PAI-1 levels were all unchanged. Levels of CRP, TNFα and IL-6 also remained unchanged. From this study we conclude that administration of topical progesterone cream at a daily dose of 20 mg significantly relieves menopausal symptoms in postmenopausal women without adversely altering prothrombotic potential. Since the thrombotic complications that are typically observed with conventional hormone replacement therapy do not seem to occur with topical progesterone, this treatment should be seriously considered as an effective and safe alternative clinical therapy for women suffering from menopausal symptoms.

Description: Background: Talabostat (PT-100), an orally available inhibitor of dipeptidyl peptidases, is in Phase 2 studies for B-cell malignancies and solid tumors. Talabostat increases production of cytokines and chemokines in lymph nodes and spleen, stimulating both adaptive and innate immune responses (Adams S, Cancer Research, 2004;64:5471). Talabostat may thus enhance the antibody-dependent cytotoxicity of MAbs such as rituximab. Methods: This is a Phase 1 study to evaluate the safety and activity of talabostat and rituximab in patients with indolent NHL who did not respond or progressed following rituximab. Rituximab 375mg/m2 was administered weekly x 4. Total daily doses of talabostat 400μg (n=6), 600μg (n=3), or 800μg (n=6) were administered BID for 6 days following each dose of rituximab. Cytokines and chemokines were assessed pre-, 2, and 6 hours post-talabostat on Days 1, 6, 13, 20, and 27. Flow cytometry was performed at baseline and Day 28. Clinical and laboratory evaluations were performed at specified times. Adverse events (AEs) were graded per NCI-CTC and recorded throughout the study. Disease assessments were performed on Days 28 and 84. Results: 11 men and 4 women aged 48–82 with NHL (n=10) or SLL/CLL (n=5) have been treated. 9 patients completed the 28-day study: 4 at 400μg, 1 at 600μg, and 4 at 800μg. Enrollment continues at 400μg/day. The most frequent AEs have been edema (67%), nausea (47%), dizziness (40%), hypotension (33%), fatigue (33%), vomiting (33%), constipation (33%), thrombocytopenia (27%), and weight gain (27%). Grade 3 toxicities include: dizziness, myopathy (400μg/day), and 2 events of thrombocytopenia (600μg/day). Grade 3 peripheral edema, myalgia, dehydration, electrolyte imbalance, hypereosinophilia, elevated CPK (primarily CK-MM), and rhabdomyolysis were seen in 2/6 patients at 800μg/day; these events were DLTs. One partial response (PR) lasting 7 months was seen in one patient (800μg/day). A PR was seen in a second patient at 800μg/day but did not meet the strict NCI-WG criteria for response. Elevations in cytokines 〉ULN were reported across all doses following talabostat: G-CSF (13/15), IL-1β (10/15), IL-2 (7/15), IL-6 (8/15), IL-8 (8/15), IL-10 (11/15), TNF-α (11/15), and IFN-γ (3/15). At Day 28 or early termination, CD20 was decreased in most (12/15) patients. Increases were seen in the percentage of CD3 (12/15), CD3/4 (11/15) and CD3/8 (9/15). In all 5 patients with SLL/CLL, CD5+/CD20+ was

Description: Background: T cells can be activated and expanded ex vivo using the Xcellerate™ Process, in which peripheral blood mononuclear cells (PBMC) are incubated with anti-CD3 and anti-CD28 antibody-coated magnetic beads (Xcyte™-Dynabeads®). In an ongoing trial of Xcellerated T Cells in subjects with chronic lymphocytic leukemia, marked and sustained reductions in lymphadenopathy and splenomegaly were observed (Wierda et al., ASCO 2004). Increases in neutrophil, platelet and NK cell counts were also documented. This study is designed to determine if similar effects can be observed in subjects with indolent non-Hodgkin’s lymphoma (NHL). Methods: Subjects must have indolent NHL (follicular, small lymphocytic, marginal zone, or mantle cell lymphoma), have relapsed or refractory disease, and have received at least 1 but not more than 4 prior treatment regimens. PBMC are collected by leukapheresis for the Xcellerate Process, and subjects subsequently receive two infusions of 20–60 x 109 Xcellerated T Cells separated by 6–8 weeks. Approximately 40 subjects will be treated. Results: Seven subjects have been enrolled and Xcellerated T Cells have been manufactured in 5 subjects to date. T cells expanded 181.8 ± 88.5 fold and the final product was 〉99.0 ± 0.0% T cells (mean + SD). One subject with small lymphocytic lymphoma has been treated with two infusions of 38.6 x 109 Xcellerated T Cells. There have been no serious adverse events to date. Following the first treatment, the lymphocyte count increased from 1.8 x 109/L to 2.9 x 109/L on Day 28. The neutrophil count also increased from 2.9 x 109/L to 5.5 x 109/L six weeks following infusion. The subject had a significant reduction in cervical lymphadenopathy and a slight decrease in bulky mesenteric lymphadenopathy six weeks following the first infusion. Conclusions: Xcellerated T Cells can be manufactured in subjects with indolent NHL. Treatment leads to significant increases in T cell and neutrophil counts. Preliminary data suggest a reduction in peripheral lymphadenopathy. Data on additional subjects will be presented.

Description: CD74, also known as HLA-DR-associated invariant chain, is a type II transmembrane glycoprotein highly expressed in many B-cell malignancies. The limited expression of CD74 in normal tissues suggests it may be a suitable ADC target for these tumor types. Accordingly, we engineered an anti-CD74 human IgG1 antibody (SP7219) using novel Fab-based ribosome display methods. The selected Fabs were readily reformatted and directly screened as IgGs using Sutro's unique high-throughput, cell-free protein synthesis platform, Xpress CFTM. We then developed novel, potent ADCs, SP7676 and SP7675 (STRO-001), comprised of our lead antibody (SP7219) conjugated to non-cleavable DBCO-maytansinoid linker-warheads with an average drug-antibody ratios (DAR) of 2. We used site-specific conjugation technology which results in a high degree of homogeneity characterized by the drug linker covalently binding to a single defined site. The sites for conjugation were selected based on highest cell killing activity and stablity in vitro and in vivo. Both ADCs demonstrate potent cell killing activity across multiple B-cell tumor lines in vitro, and anti-tumor activity in preclinical multiple myeloma xenograft models. In vitro cytotoxicity assays show nanomolar potency of STRO-001 in four MM cell lines: Mc/CAR (IC50 0.8 nM), MM.1S (IC50 10-11 nM), U266B1 (IC50 8.5 -9.3 nM), and ARP-1 (IC50 4.3-22 nM). CD74 cell surface expression is required for ADC anti-proliferative effect but the expression level does not seem to correlate with in vitro potency. SP7676 elicited a robust anti-tumor response in the ANBL-6 multiple myeloma xenograft model. Durable regressions were observed in all mice at ≥ 3 mg/kg, with equivalent efficacy (regression) at 3 mg/kg (every 3 days x5) and 10 mg/kg (every 3 days x5 or weekly x3). SP7676 also elicited a clear survival benefit in a disseminated multiple myeloma CAG xenograft model starting at 1mg/kg every 3 days x 5 doses. Similarly, both SP7676 and STRO-001 inhibited the formation of internal visceral tumors in the ARP-1 xenograft model after 3 weekly doses of 3 mg/kg. Evaluation of our lead candidate, STRO-001 in additional MM cell lines and primary patient samples is planned. The tolerability of STRO-001 in non-human primates is under evaluation. STRO-001 was administered to cynomolgous monkeys in an exploratory dose-escalating study up to 30 mg/kg x 2 doses on Day 1 and 15. STRO-001 reduces normal B-cell populations at ≥1 mg/kg after a single dose, providing pharmacodynamic evidence of B-cell targeting while other hematopoietic lineages are mostly affected only at the highest dose studied. Anticipated hematologic toxicities were readily reversible at 1, 3 and 10 mg/kg and target organs of interest were identified. Based on these encouraging data, STRO-001 is advancing to IND-enabling studies for the treatment of CD74 expressing multiple myeloma and other B-cell malignancies. Disclosures Abrahams: Sutro Biopharma: Employment. Li:Sutro Biopharma: Employment. Yu:Sutro Biopharma: Employment. Krimm:Sutro Biopharma: Employment. Kahana:Celgene: Employment. Narla:Celgene: Employment. Schwartz:Celgene: Employment. Boylan:Celgene: Employment. Hoffmann:Sutro Biopharma: Employment. Steiner:Sutro Biopharma: Employment. Zawada:Sutro Biopharma: Employment. Stephenson:Sutro Biopharma: Employment. Bruhns:Sutro Biopharma: Employment. DeAlmeida:Sutro Biopharma: Employment. Matheny:Sutro Biopharma: Employment. Bussell:Sutro Biopharma: Employment. Galan:Sutro Biopharma: Employment. Kline:Sutro Biopharma: Employment. Vasquez:Sutro Biopharma: Employment. Yam:Sutro Biopharma: Employment. Stafford:Sutro Biopharma: Employment. Heinsohn:Sutro Biopharma: Employment. Sato:Sutro Biopharma: Employment. Molina:Sutro Biopharma: Employment. Hallam:Sutro Biopharma: Employment. Lupher:Sutro Biopharma: Employment.

Description: Invasive surgery brings with it a unique set of post-surgical risks that are directly dependent on various factors including the specific surgical approach used, pre-existing comorbidities and features such as gender and age. Pulmonary thromboembolism is one of the most feared complications following surgery, and diagnosis and treatment of this entity is a challenging task for the clinician. Here we describe a case of massive pulmonary thromboembolism and associated coronary artery thromboemboli status post spinal fusion surgery in a 68 year-old man with an undetected patent foramen ovale (PFO). Although the decedent was managed clinically with proper deep venous thrombosis prophylaxis protocols and physical rehabilitation, he went into cardiorespiratory arrest after experiencing acute oxygen desaturation and newly detected right bundle branch block. PFO can be incidentally found in 25% of the adult population. Several clinical syndromes including stroke, migraine headaches and obstructive sleep apnea have been associated in patients with PFO, the last two from which the decedent suffered. The pathology of this unique case of massive pulmonary thromboembolism resulting in coronary artery thromboemboli in the setting of an undetected PFO is discussed. The discovery of PFO in patients prior to surgery, if detected early, may improve post-surgical outcomes. Figure 1. Massive pulmonary artery thromboembolism in situ, gross examination. Figure 1. Massive pulmonary artery thromboembolism in situ, gross examination. Figure 2. Histology, hematoxylin and eosin. A. Pulmonary thromboembolus at the bifurcation of the pulmonary arteries and pulmonary trunk. B. Hemorrhagic infarct and thromboemboli in varying stages of organization, right lower lobe, lung. C. Cross section of the proximal left anterior descending coronary artery with thromboembolus. D. Cross section of the posterior descending coronary artery with thromboembolus. Figure 2. Histology, hematoxylin and eosin. A. Pulmonary thromboembolus at the bifurcation of the pulmonary arteries and pulmonary trunk. B. Hemorrhagic infarct and thromboemboli in varying stages of organization, right lower lobe, lung. C. Cross section of the proximal left anterior descending coronary artery with thromboembolus. D. Cross section of the posterior descending coronary artery with thromboembolus. Figure 3. Patent foramen ovale, gross examination. Figure 3. Patent foramen ovale, gross examination. Disclosures No relevant conflicts of interest to declare.

Description: INTRODUCTION The incidence of secondary cancer (SC) in patients with myeloproliferative neoplasms (MPN) is high and comparable to that of thrombosis. However, the identification of patient subgroups that might be at increased susceptibility of developing SC has not been systematically addressed. We report here the results of an international case-control study (MPN-K) aimed at comparing the frequency of exposure to possible causes of SC in patients with classical MPN, polycythemia vera (PV), essential thrombocythemia (ET) and myelofibrosis (MF). METHODS This European Leukaemia Network (ELN) study reports MPN patients from 28 sites of 5 European countries and Israel, diagnosed in the period from 2000 to 2016. Cases were MPN patients with concomitant diagnosis of a non-myeloid SC (n=15) or its presentation during the course of the disease (n=412). Controls were MPN patients cancer-free, matched to the paired case for sex, age (±5 years), date of MPN diagnosis (±5 years), and MPN disease duration (±6 years). A multivariable conditional logistic regression model was used to estimate the effect of selected variables on total SC risk and in different types of SC. RESULTS Among 1,259 MPN patients, there were 427 cases and 832 matched controls. Cases presented melanoma (n=20; 4.7%), non-melanoma skin cancer (n=69; 16.2% - basal/squamous cell carcinoma), non-skin solid cancer (n=290; 67.9%) including breast, ovary/uterus, colorectal, upper gastrointestinal, liver/pancreas, lung, prostate/urinary, other and lymphoproliferative diseases (n=48; 11.2%) including multiple myeloma, chronic lymphocytic leukemia, low and high grade B- and T-lymphoma. At diagnosis, there were slightly more patients with PV among SC cases (n= 152; 35.6%) than controls (n=256; 30.8%), while conversely there were slightly less ET patients among cases (n=196; 45.9%) than controls (n=426; 51.2%). Cases and controls presented similar proportion of MF diagnosis (n=79 cases, 18.5% and 150 controls, 18.0%). Driver mutations (JAK2 V617, EXON-12, CALR, MPL), non-driver mutations and abnormal karyotype were equally represented in cases and controls. Other variables such as cardiovascular risk factors, exposure to cancerogens, family history of cancer and chronic inflammatory diseases were reported with similar frequency in cases and controls. After MPN diagnosis, exposure to first and other lines of treatments until the index event, with Phlebotomy (n=193; 15.3%), Hydroxyurea (n=814; 64.7%), Anagrelide (n=14; 1.1%), Interferon (n=30; 2.4%), Pipobroman (n=8; 0.6%), Busulphan (n=13; 1.0%), Ruxolitinib (n=11; 0.9%), was similar in the two groups except for aspirin that was used less frequently (p=0.043) in cases (n=320; 74.9%) compared to controls (n=664; 79.9%). In particular, the lower use of aspirin was circumscribed to non-skin solid tumors. A multivariable analysis was carried out in all patients and stratified by different type of tumors (Table). In non-skin solid cancers, the time to exposure of the MPN disease 〉 5 years (OR=2.95; 95% CI 1.54-5.66, p=0.001) and the PV phenotype (OR=2.40, 95% CI 1.15-5.01, p=0.020) were more burdened by the incidence of events than the reference ET group. No difference in SC risk was found for MF patients compared to patients with ET. Interestingly, the independent protective role of aspirin retained its statistical significance only in non-skin SC. In non-melanoma skin cancer, multivariable analysis revealed that the presence of JAK2 mutation was less associated with SC (OR=0.32, 95% CI 0.13-0.81, p=0.016) and confirmed that exposure to HU and other cytotoxic agents was associated with a significantly higher risk of SC (OR=6.00, 95% CI 1.23-29.28, p=0.027 and OR=9.80, 95% CI 1.24-77.78, p=0.031, respectively). This finding was not seen in non-skin SC and in lymphoma. CONCLUSION The considered clinical and biological features, at MPN diagnosis, were not different in cases with SC and controls. During the course of the disease, three factors significantly and independently affected the risk of SC in these MPN patients: 1) patients with PV had a 77% higher risk than those with ET, 2) patients with MPN duration of more than 5 years had a twice higher risk than those with lower duration, 3) for the first time, we documented that in non-skin solid cancers, aspirin treatment reduced SC risk of 38%. Exposure to HU and other cytoreductive drugs was confirmed as a risk factor for non-melanoma skin cancer. Disclosures Palandri: Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Marchetti:Gilead: Consultancy; takeda: Speakers Bureau; amgen: Speakers Bureau; janssen: Speakers Bureau. Griesshammer:Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: A case of erythremic myelosis is described which was characterized by a severe anemia from the beginning. There was irregular remitting fever, splenomegaly and hepatomegaly. The peripheral blood showed immature erythroblasts, granulopenia and thrombocytopenia. The bone marrow showed hyperplasia of erythropoiesis with maturation arrest, and a persistent megaloblastic type of nucleus in abnormal red cells. There was also a well defined proliferation of the reticulo-endothelial system. The course was that of the subacute variety of erythremic myelosis, but it began with an acute phase and ended acutely. A remission of nearly three months without transfusion followed a transfusion of fresh blood. While this may be coincidental with a spontaneous remission we feel that it is probable that a maturation factor in the fresh blood was responsible. For this reason we feel it is reasonable to suppose that other cases of erythremic myelosis will benefit more from fresh blood than from stored blood; and, as in our case, the inevitable fatal outcome after two months or less can be postponed for an appreciable number of months.

Description: Introduction Malignancy can be heralded by unprovoked venous thromboembolism (VTE) but also by arterial thrombosis. To date it is unknown whether this association is present also in myeloproliferative neoplasms (MPN), in which arterial thrombosis is more frequent that venous thrombosis and solid tumors are reported with an increased frequency. The MPN-K nested case-control study addressed the impact of cytoreductive drugs on the risk of developing second cancer in MPN patients (Barbui T et al, Leukemia 2019); here we re-examined the study database to evaluate the frequency and type of vascular complications in MPN patients with second cancer excluding leukemia and to establish whether arterial and venous thrombosis during follow-up after diagnosis of MPN could predict the occurrence of a second cancer. Patients and methods Cases were patients with second cancer diagnosed concurrently or subsequent to the diagnosis of MPN. Controls were MPN patients without second cancer. For each case with second cancer, up to 3 cancer-free controls were matched by each center for sex, age at MPN diagnosis, date of MPN diagnosis, and MPN disease duration. Each set consisting of one case and their matched-controls had a similar observational period (from MPN diagnosis until the index date of diagnosis for the second cancer). The study included 647 cases with second cancer (carcinoma, non-melanoma-skin cancers, hematological secondary cancer and melanoma). The most frequent category was carcinoma (n=426, 65.8%). Cases were comparable with the 1,234 matched controls for demographics, type of MPN, and exposure to potential confounders such as mutational profile, abnormal karyotype and cardiovascular risk factors. The thrombotic events of interest were ischemic stroke, transient ischemic attacks, acute coronary syndromes, peripheral arterial thrombosis, deep venous thrombosis (including thrombosis of cerebral and splanchnic veins) and pulmonary embolism. Thrombosis had to be concurrent with or in the 2 years before MPN diagnosis or occurring after MPN diagnosis. The cumulative incidence of either arterial or venous thrombosis from MPN diagnosis was estimated by the Kaplan-Meier method and was compared between cases and controls using the log-rank test. A conditional logistic regression model estimated the Odds Ratio (OR) with 95% Confidence Interval (CI) of second cancer associated with the occurrence of thrombosis before/at diagnosis of MPN and during follow-up. Other covariates were patient age, cardiovascular risk factors, the JAK2V617F mutation, and treatment during follow-up. Results Approximately 20% of either MPN cases or controls had thrombosis before MPN or at diagnosis (19.8% vs. 21.1%, respectively, p=0.462). After a median observation time from diagnosis of MPN to an index date of 4.5 years (interquartile range 1.5-8.2) in cases and 3.7 years (interquartile range 1.5-7.5) in controls, cases showed a percentage of thrombosis higher than in controls (75/647, 11.6% vs. 100/1234, 8.1%, respectively, p=0.013). Approximately one-third of thrombosis preceding cancer occurred in the 12 months before the diagnosis of second cancer (22/75, 29.3%). The excess of thrombosis in cases was due to a higher frequency of arterial thrombosis (6.2% vs. 3.7%, p=0.015), whereas no significant difference was found for venous thrombosis (5.4% vs. 4.3%, p=0.277). While the cumulative incidence of venous thrombosis over time was similar among cases and controls (p=0.864), the cumulative incidence of arterial thrombosis was higher in cases with second cancer (p=0.006) (Figure 1). The excess of arterial thrombosis after MPN diagnosis was limited to cases with carcinoma (6.8% vs 3.9%, p=0.027). In a multivariable model, arterial thrombosis during the follow-up was confirmed to be an independent predictor factor for carcinoma, with an odds ratio of 1.97 (95%CI 1.14-3.41, p=0.015). Conclusions. These findings reveal an association of arterial thrombosis with subsequent second cancer (namely carcinoma) in MPN patients. A possible biological plausibility for this link may be related to an underlying common pathogenic mechanism such as an aberrant inflammatory response consistently found in MPN. This observation may have practical implications and suggests careful clinical surveillance for early diagnosis of second cancer in MPN patients with arterial thrombosis during the follow-up. Disclosures Palandri: Novartis: Consultancy, Honoraria. Iurlo:Novartis: Other: Speaker Honoraria; Incyte: Other: Speaker Honoraria; Pfizer: Other: Speaker Honoraria. Bonifacio:Incyte: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Pfizer: Honoraria; BMS: Honoraria. Rumi:novartis: Honoraria, Research Funding. Elli:Novartis: Membership on an entity's Board of Directors or advisory committees. Lunghi:Pfizer: Honoraria; Novartis: Honoraria; Incyte: Honoraria. Benevolo:Novartis Pharmaceuticals: Consultancy. McMullin:Italopharma: Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Speakers Bureau; Daiko Sanyo: Membership on an entity's Board of Directors or advisory committees. Griesshammer:Novartis: Consultancy, Honoraria, Speakers Bureau. Vannucchi:CTI: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Membership on an entity's Board of Directors or advisory committees; Italfarmaco: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene Corporation: Membership on an entity's Board of Directors or advisory committees. Rambaldi:Pfizer: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau.

Description: Hemochromatosis is a common disorder characterized by excess iron absorption and accumulation of iron in tissues. Usually hemochromatosis is inherited in an autosomal recessive pattern and is caused by mutations in the HFE gene. Less common non-HFE–related forms of hemochromatosis have been reported and are caused by mutations in the transferrin receptor 2 gene and in a gene localized to chromosome 1q. Autosomal dominant forms of hemochromatosis have also been described. Recently, 2 mutations in theferroportin1 gene, which encodes the iron transport protein ferroportin1, have been implicated in families with autosomal dominant hemochromatosis from the Netherlands and Italy. We report the finding of a novel mutation (V162del) in ferroportin1 in an Australian family with autosomal dominant hemochromatosis. We propose that this mutation disrupts the function of the ferroportin1 protein, leading to impaired iron homeostasis and iron overload.

Description: Cytogenetics has proven an essential tool not only for confirming a diagnosis/classification, but for providing prognostic value as well in myelodysplastic syndromes (MDS). However, approximately 50% of primary MDS do not show discernible chromosome changes. In recent years, the fluorescence in situ hybridization (FISH) technique using gene or chromosome locus/region specific probes has emerged as a promising test in various hematopoietic and lymphoid neoplasms. To evaluate the application of FISH panels and cytogenetic studies in MDS, we retrospectively analyzed 1,885 consecutive bone marrow results from patients with suspected MDS due to cytopenia(s). In particular, we assessed the additional information a FISH reflex testing might have given in cytogenetically normal cases. The probes used in the panel included the EGR1 at 5q31, the D7S522 at 7q31, the D8Z2 for the centromere of chromosome 8, the MLL at 11q23 and the D20S108 at 20q12 (Vysis, Inc.). Among all patients, 190 (10%) had clonal chromosome abnormalities, mostly as reported in the literatures, eg, -5/5q- accounted for 34.7% of abnormalities, trisomy 8 29.5%, -7/7q- 14.2%, 20q- 13.7%. Of 345 cases with a FISH reflex test ordered and performed, only 3 (0.87%) showed positive results: a deletion of 7q31, a deletion of 20q12 and a deletion of 5q31 in 9.6%, 8.2% and 71.5% of interphase cells respectively. For the case with 5q- detected by FISH, only 12 metaphases were available for cytogenetic analysis. From our data and experience, at present, interphase FISH panel testing seems not to be an efficient and cost-effective method used as a screening test for cytopenia(s) in the diagnosis of MDS, different from its applications in B-cell chronic lymphoid leukemias, non-Hodgkin lymphomas and plasma cell neoplasms where neoplastic cells inherited not to divide easily in culture for metaphase analysis. Rather, it should be used for suspected MDS cases as a technique of choice for problematic specimens compromised for cytogenetic analysis such as cellular insufficiency, extended transit time and extremely low mitotic index or poor chromosome morphology. Until more genetic defect targeted probes become available with a better understanding of the stem cell biology and pathogenesis in MDS, cytogenetics is still the best and a “must” technique for detecting genomic aberrations in MDS and nearly all other myeloid hematopoietic neoplastic disorders.