Continuing to strengthen FDA's science approach to emerging technologies.

Emerging technologies result when advances and innovation in technology lead to discoveries. Often emerging technologies stimulate novel research in medical product development that contribute to new approaches to manufacturing and can improve the quality of products. By supporting investments in agency coordination, staff training and professional development, regulatory science research, stakeholder engagement, and enhancing opportunities for expert input, the U.S. Food and Drug Administration plays a critical role in translating innovations into novel safe and effective medical products that improve the public health.

Regulation of xenogeneic porcine pancreatic islets.

The use of xenogeneic porcine pancreatic islets has been shown to be a potentially promising alternative to using human allogeneic islets to treat insulin-dependent type 1 diabetes (T1D). This article provides an overview of the existing FDA regulatory framework that would be applied to the regulation of clinical trials utilizing xenogeneic porcine pancreatic islets to treat T1D.

A randomized trial of preemptive therapy for prevention of cytomegalovirus disease after allogeneic hematopoietic stem cell transplantation.

We studied the efficacy of two different doses of ganciclovir to prevent cytomegalovirus (CMV) disease in allogeneic hematopoietic stem cell transplantation (HSCT) recipients. We randomly assigned allogeneic HSCT recipients who had CMV infection to receive preemptive ganciclovir therapy with or without induction phase (5 mg/kg twice daily for 1 week). Thirty-two and thirty-six patients were randomized to the standard and the low-dose therapy group, respectively. The median time to CMV antigenemia or viremia clearance was 7 days (3-25 days) in the standard therapy group versus 11 days (3-69 days) in the low-dose therapy group (P = 0.540). The incidence of CMV disease was similar between the two groups (P = 0.366). The Kaplan-Meier estimate of event-free survival by day 180 after HSCT was 76.2% in the standard therapy group versus 66.7% in the low-dose therapy group (P = 0.590). Severe neutropenia (<0.5 x 10(9)/L) was observed in four (12.5%) patients in the standard therapy group versus two (5.6%) patients in the low-dose therapy group (P = 0.314). This study suggests that a low-dose ganciclovir preemptive therapy can be as effective as the standard-dose ganciclovir preemptive therapy for the prevention of CMV disease in allogeneic HSCT recipients.

Considerations for tissue-engineered and regenerative medicine product development prior to clinical trials in the United States.

Tissue-engineered and regenerative medicine products are promising innovative therapies that can address unmet clinical needs. These products are often combinations of cells, scaffolds, and other factors and are complex in both structure and function. Their complexity introduces challenges for product developers to establish novel manufacturing and characterization techniques to ensure that these products are safe and effective prior to clinical trials in humans. Although there are only a few commercial products that are currently in the market, many more tissue-engineered and regenerative medicine products are under development. Therefore, it is the purpose of this article to help product developers in the early stages of product development by providing insight into the Food and Drug Administration (FDA) process and by highlighting some of the key scientific considerations that may be applicable to their products. We provide resources that are publically available from the FDA and others that are of potential interest. As the provided information is general in content, product developers should contact the FDA for feedback regarding their specific products. Also described are ways through which product developers can informally and formally interact with the FDA early in the development process to help in the efficient progression of products toward clinical trials.

Depletion of L-ascorbic acid alternating with its supplementation in the treatment of patients with acute myeloid leukemia or myelodysplastic syndromes.

PURPOSE: L-ascorbic acid (LAA) modifies the in vitro growth of leukemic cells from approximately 50% of patients with acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS). To test the hypothesis that depletion of LAA, alternating with supplementation to prevent scurvy, would provide therapeutic benefit, a single-arm pilot trial was conducted (ClinicalTrials.gov identifier: NCT00329498). Experimental results: During depletion phase, patients with refractory AML or MDS were placed on a diet deficient in LAA; during supplementation phase, patients received daily intravenous administration of LAA. An in vitro assay was performed pretherapy for LAA sensitivity of leukemic cells from individual patients. RESULTS: Of 18 patients enrolled, eight of 16 evaluable patients demonstrated a clinical response. Responses were obtained during depletion (four patients) as well as during supplementation (five patients) but at a pharmacologic plasma level achievable only with intravenous administration. Of nine patients for whom the in vitro assay indicated their leukemic cells were sensitive to LAA, seven exhibited a clinical response; compared with none of six patients who were insensitive to LAA. CONCLUSIONS: The clinical benefit, along with a conspicuous absence of significant adverse events, suggests that further testing of LAA depletion alternating with pharmacologic dose intravenous supplementation in patients with these and other malignancies is warranted.

Mechanically activated integrin switch controls alpha5beta1 function.

The cytoskeleton, integrin-mediated adhesion, and substrate stiffness control a common set of cell functions required for development and homeostasis that are often deranged in cancer. The connection between these mechanical elements and chemical signaling processes is not known. Here, we show that alpha(5)beta(1) integrin switches between relaxed and tensioned states in response to myosin II-generated cytoskeletal force. Force combines with extracellular matrix stiffness to generate tension that triggers the integrin switch. This switch directly controls the alpha(5)beta(1)-fibronectin bond strength through engaging the synergy site in fibronectin and is required to generate signals through phosphorylation of focal adhesion kinase. In the context of tissues, this integrin switch connects cytoskeleton and extracellular matrix mechanics to adhesion-dependent motility and signaling pathways.

Cole-Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass.

This work evaluates three techniques of calibrating capacitance (dielectric) spectrometers used for on-line monitoring of biomass: modeling of cell properties using the theoretical Cole-Cole equation, linear regression of dual-frequency capacitance measurements on biomass concentration, and multivariate (PLS) modeling of scanning dielectric spectra. The performance and robustness of each technique is assessed during a sequence of validation batches in two experimental settings of differing signal noise. In more noisy conditions, the Cole-Cole model had significantly higher biomass concentration prediction errors than the linear and multivariate models. The PLS model was the most robust in handling signal noise. In less noisy conditions, the three models performed similarly. Estimates of the mean cell size were done additionally using the Cole-Cole and PLS models, the latter technique giving more satisfactory results.

Biomimetic carbohydrate substrates of tunable properties using immobilized dextran hydrogels.

Glycidylmethacrylate-modified dextran macromers (Dex-GMA) of different degrees of substitution (DS) were synthesized. The elastic modulus of the hydrogels produced using one-component and two-component macromer systems was measured using rheometry. When one macromer of DS 1/10 was used, a hydrogel modulus in the range of 0.2 Pa to 42 kPa was obtained by varying the Dex-GMA concentration from 80 to 200 mg/mL. When a mixture of two macromers of different DS (1/10 and 1/23) was used, a more uniform variation of modulus in the range of 0.4 Pa to 42 kPa was achieved by controlling the ratio of the two macromers. When dextran hydrogels were functionalized with fibronectin and immobilized onto glass substrates, the attachment, spreading, and growth of human aortic smooth muscle cells were modulated by the elastic properties of the dextran matrix. The dextran hydrogel system with tunable mechanical and biochemical properties appears promising for applications in cell culture and tissue engineering.

Outcomes of a modified CALGB 19802 regimen in adult acute lymphoblastic leukemia.

We analyzed the efficacy and toxicity of a modified Cancer and Leukemia Group B (CALGB) 19802 regimen in adult acute lymphoblastic leukemia (ALL). From February 2002 to August 2005, 25 adults with untreated ALL were enrolled in the study. Compared to the original regimen, the modified CALGB 19802 regimen consisted of a 4-drug induction (cyclophosphamide, daunorubicin, vincristine, and prednisone) instead of a 5-drug induction (L-asparaginase was added to the previous regimen). This was followed by high-dose methotrexate (1,000 mg/m(2) x 3 days) and cytarabine (2,000 mg/m(2) x 4 days) for the consolidation cycles. High-dose systemic and intrathecal methotrexate was given for central nervous system prophylaxis. Twenty-three patients (92%) achieved a complete remission (CR), and two patients (8%) had refractory disease. With a median follow-up of 21.5 months, 10 patients (40%) were alive and continued to be in CR. The 3-yr probability of an event-free survival and the overall survival were 39.0% and 47.4%, respectively. Treatment related mortality and major grade 3 to 4 neurotoxicity occurred in 1 patient and 3 patients, respectively. The modified CALGB 19802 regimen demonstrated a high remission rate and a favorable survival rate.

Changes in serologic markers of hepatitis B following autologous hematopoietic stem cell transplantation.

Korea is an endemic area for hepatitis B virus (HBV) infection. Reactivation of HBV is a well-recognized complication in patients with chronic HBV infection undergoing cytotoxic or immunosuppressive therapy, and there are some reports of hepatitis B reverse seroconversion after HSCT. This study evaluated changes in HBV serology after HSCT. We reviewed the medical records of 141 patients who had available HBV serologic data after autologous HSCT. Patient information was retrospectively collected from the BMT database. Before transplantation, 12 patients were positive for hepatitis B surface antigen (HBsAg) and received lamivudine prophylaxis. There was 1 case of reactivation of HBV among these patients. One hundred twenty-nine patients were negative for HBsAg before HSCT, of whom 110 were positive and 19 were negative for hepatitis B surface antibody (anti-HBs). Sixty-two of the 110 patients who were positive for anti-HBs were also positive for hepatitis B core antibody (anti-HBc). Eight patients were negative for anti-HBs and anti-HBc. Seven patients who were initially negative for HBsAg were identified as positive after HSCT, and 5 of those 7 patients developed acute hepatitis, thus indicating reverse seroconversion. Univariate analysis showed that reverse seroconversions were observed more frequently with multiple myeloma than another disease (P = .005; relative risk, 11.854; 95% confidence interval, 1.381-101.770). Other factors, such as age, sex, and presence of HBcAb before HSCT, had no statistically significant affect on reverse seroconversion. In conclusion, reverse seroconversion of HBV is not a rare complication of autologous HSCT, and the risk of reverse seroconversion after treatment is a serious concern due to possible complications arising from patients' suppressed immune systems.

Adhesion of MC3T3-E1 cells to RGD peptides of different flanking residues: detachment strength and correlation with long-term cellular function.

We synthesized a series of RGD peptides and immobilized them to an amine-functional self-assembled monolayer using a modified maleimide-based conjugate technique that minimizes nonspecific interactions. Using a spinning disc apparatus, a trend in the detachment strength (tau(50)) of RGD peptides of different flanking residues was found: RGDSPK > RGDSVVYGLR approximately RGDS > RGES. Using blocking monoclonal antibodies, cellular adhesion to the peptides was shown to be primarily alpha(v)-integrin-mediated. In contrast, the tau(50) value of the cells on fibronectin (Fn)-coated substrates of similar surface density was 6-7 times higher and involved both alpha(5)beta(1) and alpha(v)beta(3) integrins. Cellular spreading was enhanced on RGD peptides after 1 h when compared to RGE and unmodified substrates. However, no significant differences were observed between the different RGD peptides. Long-term function of MC3T3-E1 cells was also evaluated by measuring alkaline phosphatase (ALP) activity and mineral deposition. Among the four peptides, RGDSPK exhibited the highest level of ALP activity after 11 days and mineralization after 15 days and reached comparable levels as Fn substrates after 15 and 24 days, respectively. These findings collectively illustrate both the advantages and limitations of enhancing cellular adhesion and function by the design of RGD peptides.

Effect of biomaterial surface properties on fibronectin-alpha5beta1 integrin interaction and cellular attachment.

The ability of fibronectin (Fn) to mediate cell adhesion through binding to alpha(5)beta(1) integrins is dependent on the conditions of its adsorption to the surface. Using a model system of alkylsilane SAMs with different functional groups (X=OH, COOH, NH(2) and CH(3)) and an erythroleukemia cell line expressing a single integrin (alpha(5)beta(1)), the effect of surface properties on the cellular adhesion with adsorbed Fn layers was investigated. (125)I-labeled Fn, a modified biochemical cross-linking/extraction technique and a spinning disc apparatus were combined to quantify the Fn adsorption, integrin binding and adhesion strength, respectively. This methodology allows for a binding equilibrium analysis that more closely reflects cellular adhesion found in stable tissue constructs in vivo. Differences in detachment strength and integrin binding were explained in terms of changes in the adhesion constant (psi, related to affinity) and binding efficiency of the adsorbed Fn for the alpha(5)beta(1) integrins (CH(3) approximately NH(2)

Extranodal nasal type NK/T-cell lymphoma: elucidating clinical prognostic factors for risk-based stratification of therapy.

The purpose of this study was to define distinctive clinical features of "nasal" and "nasal-type" NK/T cell lymphomas by assessing prognostic factors. The anatomic definition of extranasal NK/T cell lymphoma has been vague resulting in variable definitions of extranasal sites by different groups. We analysed the clinical behavior of 90 NK/T cell lymphoma patients and attempted to elucidate the prognostic factors for risk-based stratification of therapy. We observed no significant difference between "nasal" and "nasal-type" NK/T cell lymphomas in regards to clinical features and survival using the conventional anatomic classification. We suggest the categorisation of the two subtypes of NK/T cell lymphoma as follows: UNKTL (upper aerodigestive tract NK/T cell lymphoma) including all lymphomas confined to nasal cavity, nasopharynx, and the upper aerodigestive tract and EUNKTL (extra-upper aerodigestive tract NK/T cell lymphoma) group to include all sites other than the UNKTL group. The EUNKTL group in this study had advanced stage at diagnosis, higher LDH, higher IPI score, poorer performance and inferior response to the anthracycline-based chemotherapy with statistical significance. There was a significant difference in survival rate between EUNKTL and UNKTL group (20.0%, 54.0%, respectively, P = 0.0068). More aggressive treatment should be sought for this particular group of patients for EUNKTL patients.

Influential factors for the collection of peripheral blood stem cells and engraftment in acute myeloid leukemia patients in first complete remission.

Although several studies have investigated factors influencing peripheral blood stem cell (PBSC) mobilization in patients with nonmyeloid malignancies in an effort to increase the efficiency of autologous PBSC transplantation (APBSCT), there are very few reports on the efficiency of PBSC mobilization in patients with leukemia. We analyzed the effects of influential variables on successful mobilization and the correlation between infused cell doses and engraftment in acute myeloid leukemia (AML) patients in first complete remission (CR1) who received APBSCT. Between May 1998 and May 2003, 34 patients with AML underwent APBSC collections at our institution. All patients were in CR1 at the time of transplantation. Except for 1 patient, all patients successfully achieved the target CD34(+) cell yield of > or = 2 x 10(6)/kg. Among progenitor cells, the CD34(+) cell dose and the colony-forming unit-granulocyte-macrophage count showed significant correlations with neutrophil and platelet engraftments. The time to neutrophil engraftment was inversely correlated to the number of infused CD34(+) cells (r = -0.67; P < .001), whereas the time to neutrophil engraftment was not significantly correlated with the number of monocytes (r = 0.20; P = .701) or the number of nucleated cells (r = 0.35; P = .062). The time to platelet engraftment was significantly correlated with the dose of infused CD34(+) cells (r = -0.47; P = .012). The univariate analysis showed that more CD34(+) cells per kilogram and more CD34(+) cells per kilogram per day were collected from patients who had a shorter interval (less than 2 months) between diagnosis and PBSC harvest (P = .0111). In conclusion, this study showed that the CD34(+) cell dose was most strongly correlated with a successful engraftment in AML CR1 patients who underwent APBSCT. The proper timing of PBSC collections should be explored to optimize the outcome of APBSCT in AML CR1 patients.

Infused CD34+ cell dose predicts long-term survival in acute myelogenous leukemia patients who received allogeneic bone marrow transplantation from matched sibling donors in first complete remission.

Allogeneic stem cell transplantation (ASCT) has improved the outcome of acute myelogenous leukemia (AML). To further improve the treatment outcome of ASCT in AML, finding a modifiable prognostic factor is mandatory. We evaluated the effect of CD34(+) cell dose on survival in allogeneic bone marrow transplantation (BMT) from HLA-matched sibling donors for AML patients in first complete remission (CR1). The 99 patients included in our analysis were classified into high CD34(+) cell dose group (CD34(+) cells > or = 2.5 x 10(6)/kg) and low CD34(+) cell dose group (CD34(+) cells < 2.5 x 10(6)/kg). The high CD34(+) cell dose patients had better overall survival (5-year overall survival rate, 75% +/- 6% vs 52% +/- 9%; P = .01) and leukemia-free survival (5-year leukemia-free survival rate, 70% +/- 6% vs 44% +/- 9%; P = .04). CD34(+) cell dose was the only independent prognostic factor in overall survival and leukemia-free survival. The high CD34(+) cell dose group had a lower relapse incidence with a borderline statistical significance (5-year relapse rate, 27% +/- 6% vs 50% +/- 10%; P = .09). There were no differences in the engraftment of neutrophil and platelet, grade II-IV acute graft-versus-host disease (GVHD), extensive-stage chronic GVHD, and transplant-related mortality between the high and low CD34(+) cell dose groups. We confirmed that high CD34(+) cell dose favorably affects the outcomes in allogeneic BMT for AML. The effort to attain a high CD34(+) cell dose should be pursued during bone marrow harvest in allogeneic BMT for AML in CR1.

The effect of non-specific interactions on cellular adhesion using model surfaces.

The contribution of non-specific interactions between cells and model functional surfaces was measured using a spinning disc apparatus. These model functional surfaces were created using self-assembled monolayers (SAM) of alkylsilanes terminated with epoxide, carboxyl (COOH), amine (NH(2)), and methyl (CH(3)) groups. These SAMs were characterized using ellipsometry, atomic force microscopy, contact angle goniometry, and X-ray photoelectron spectroscopy to confirm the presence of well-formed monolayers of expected physicochemical characteristics. All substrates also demonstrated excellent stability under prolonged exposure (up to 18 h) to aqueous conditions. The adhesion strength of K100 erythroleukemia cells to the functional substrates followed the trend: CH(3) < COOH approximately epoxide << NH(2). The NH(2) SAM surface exhibited nearly an order of magnitude greater adhesion strength than the other SAMs and this non-specific effect exceeded the adhesion measured when RGD tri-peptides were also immobilized on the surface. These findings illustrate the importance of substrate selection in quantitative studies of peptide-mediated cellular adhesion.

Docetaxel plus cisplatin as second-line therapy in metastatic or recurrent advanced gastric cancer progressing on 5-fluorouracil-based regimen.

The purpose of this study was to determine the activity and safety of docetaxel plus cisplatin as second-line chemotherapy for advanced gastric cancer. This trial included patients who had failed first-line chemotherapy with a 5-fluorouracil regimen within 1 year before their enrollment. After registration, patients were treated with docetaxel intravenously at a dose of 60 mg/m2 given over 1 hour followed by cisplatin 60 mg/m2 given over 2 hours. The treatment was continued every 3 weeks until disease progression or unacceptable toxicity was detected. Forty-three patients were registered and 41 were assessable for response. Seven partial responses were observed (17.1% of the "evaluable" patients; 95% confidence interval [CI], 0-29) with a median response duration of 3.9 months. Stable disease was documented in 2 cases (4.9%). The median survival was 5.8 months (95% CI, 3.4-8.3), resulting in a 1-year survival rate of 23%. Tolerance was acceptable, with the main toxicity being neutropenia. The authors conclude that second-line chemotherapy with docetaxel plus cisplatin for advanced gastric cancer is feasible with an acceptable toxicity level.

Primary pulmonary non-Hodgkin's lymphoma.

BACKGROUND: Primary pulmonary non-Hodgkin's lymphoma is a very rare neoplasm. It is represented most commonly by marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. Although there have been a few reviews of this lymphoma, clinical features, diagnostic procedure, optimal management and prognostic factors have not been well defined. METHODS: We reviewed the medical records of 24 patients who were pathologically and clinically diagnosed as primary pulmonary lymphoma between September 1995 and June 2003. RESULTS: There were 13 patients with MALT lymphoma and two with MALT lymphoma accompanied by large B-cell lymphoma, seven with diffuse large B-cell lymphoma and two with anaplastic large cell lymphoma. Half the patients were asymptomatic at presentation; 46% had respiratory symptoms and 16.7% had B-symptoms. Initial radiological findings were variable including nodules, masses, infiltrates or consolidation. The majority of patients (66.7%) needed surgical approaches (open thoracotomy or video-assisted thoracoscopy) for definite diagnosis. Bronchoscopy was performed in 83%, but only 30% showed a diagnostic yield. The 13 patients with MALT lymphoma were treated with a variety of modalities such as observation, surgery and single or combination chemotherapy, and combination chemotherapy was administered to 11 patients with non-MALT lymphoma regardless of surgery. The overall survival rate at 3 years for all 24 patients was 86% with a median follow-up of 32 months. CONCLUSION: Although this entity of lymphoma appears to have a good prognosis, further clinical experience and long-term follow-up are needed to identify prognostic factors.

L-ascorbic acid represses constitutive activation of NF-kappaB and COX-2 expression in human acute myeloid leukemia, HL-60.

There is increasing evidence that L-ascorbic acid (LAA) is selectively toxic to some types of cancer cells at pharmacological concentrations, functioning as a pro-oxidant rather than as an anti-oxidant. However, the molecular mechanisms by which LAA initiates cellular signaling leading to cell death are still unclear. In an effort to gain insight into these mechanisms, the effects of LAA on eukaryotic transcription nuclear factor NF-kappaB and cyclooxygenase-2 (COX-2) expression were investigated. In the present study, LAA suppressed DNA binding activity of NF-kappaB, composed of a p65/p50 heterodimer, through inhibition of degradation of inhibitory kappaB-alpha (IkappaB-alpha) and prevention of nuclear translocation of p65. The inhibitory effect of LAA on NF-kappaB activity was dependent upon glutathione levels in HL-60 cells, as well as generation of H2O2 but not superoxide anion. LAA also downregulated the expression of COX-2, which has a NF-kappaB binding site on its promoter, through repressing NF-kappaB DNA binding activity. Moreover, cotreatment of 1 microM arsenic trioxide (As2O3) with various concentrations of LAA enhanced an LAA-induced repression of NF-kappaB activity and COX-2 expression. In conclusion, our data suggest that LAA exerts its anti-tumor activity through downregulation of NF-kappaB activity and COX-2 expression, and these inhibitory effects can be enhanced by co-treatment with As2O3.

Extrapulmonary small-cell carcinoma: a single-institution experience.

BACKGROUND: Extrapulmonary small-cell carcinoma (EPSCC) has been recognized as a clinicopathological entity distinct from small-cell carcinoma (SCC) of the lung. This study aimed to review the clinical features, therapy and natural course of patients with EPSCC in Oriental single-institution series. METHODS: We retrospectively reviewed the medical records of patients with SCC between September 1995 and December 2002. Study eligibility required that patients had pathologically proven SCC in sites other than lung and normal radiological findings of the chest and normal sputum cytology or negative bronchoscopic findings. RESULTS: Twenty-four patients with EPSCC were identified and primary sites were various: uterine cervix in seven (29%), urinary bladder in five, colon or rectum in three, kidney in two and stomach, esophagus, pancreas, common bile duct, larynx, parotid gland, thymus in one each. Sixteen patients (66.7%) had limited disease (LD) and eight had extensive disease (ED). Patients with ED received mostly platinum-based chemotherapy, for which the response rate was 57%, but showed an aggressive natural history, with median overall survival (OS) of 9.2 months. Patients with LD were treated with a variety of therapeutic modalities. LD SCC of the cervix showed a favorable clinical course, with five patients being disease-free with a median follow-up of 28.4 months. Patients with LD SCC of sites other than cervix had an aggressive course with a median OS of 9.6 months. CONCLUSION: EPSCC was identified in various sites, with the most common primary site being the uterine cervix. Regardless of the primary site or disease stage, EPSCC of sites other than cervix was usually a fatal disease with a discouraging outcome for various treatment modalities.