Ultrasound guided alcohol ablation of Morton's neuroma

BACKGROUND

Morton's neuroma is a common cause of metatarsalgia. This study evaluated the efficacy of ultrasound guided alcohol injection as a treatment for this condition.

METHOD

Data from 87 treatment courses were included in this study with a mean follow of 14.3 months.

RESULTS

Technical success was 100%. One patient developed symptoms consistent with an allergic reaction to the injection and one patient declined further injection because of periprocedural pain. Partial or total treatment response was achieved in 66%, with 32% of patients having complete resolution of pain. The median visual analogue score (VAS) decreased from 8 pre-procedure to 4 post-procedure (p < 0.0001). Procedural success was greater in patients under 55 years old and in those with solitary neuromas. Seventeen patients (20%) went on to have surgery due to continuing pain.

CONCLUSION

Ultrasound guided alcohol ablation for the treatment of Morton's neuroma was a safe procedure that significantly reduced pain and may offer an alternative therapy to surgery.

Progressive multifocal leukoencephalopathy restricted to the posterior fossa in a patient with systemic lupus erythematosus

Progressive multifocal leukoencephalopathy is a neurological infectious disease caused by the John Cunningham polyomavirus (JCV), an opportunistic agent with worldwide distribution. This disease is frequently seen in immunosuppressed patients and rarely associated with systemic lupus erythematosus. In the central nervous system PML demyelinating lesions occur in the supratentorial compartment. The authors describe a rare case of PML secondary to SLE treatment with atypical presentation restricted to the posterior fossa.

Phase I study of the botanical formulation PHY906 with capecitabine in advanced pancreatic and other gastrointestinal malignancies

PURPOSE

The botanical formulation, PHY906, has been used widely in Eastern countries to treat gastrointestinal symptoms including diarrhea, nausea and vomiting. PHY906 may also have anti-tumor properties and may potentiate the action of several chemotherapeutic agents based on pre-clinical studies. We conducted a Phase I study using PHY906 in combination with capecitabine in patients with advanced pancreatic and gastrointestinal malignancies to determine the maximum tolerated dose (MTD) of capecitabine in combination with PHY906.

PATIENTS AND METHODS

This study was a single institution, open-label, Phase I study of PHY906 800mg BID on days 1-4 in combination with escalating doses of capecitabine (1000, 1250, 1500, and 1750mg/m(2)) orally twice daily on days 1-7 of a 14-day cycle (7/7 schedule). Capecitabine was increased until the appearance of dose limiting toxicities (DLTs). Measurements of efficacy included tumor response by Response Evaluation Criteria in Solid Tumors (RECIST).

RESULTS

Twenty-four patients with a median age of 67 years (range 40-84) with pancreatic cancer (15), colon cancer (6), cholangiocarcinoma (1), esophageal cancer (1) and unknown primary (1) received a total of 116 cycles (median 5 cycles; range 1-17 cycles) over 4 dose levels of capecitabine. One DLT (Grade 4 AST/ALT, Grade 3 hyponatremia) was observed in the 1000mg/m(2) cohort of patients. No further DLT was observed in the subsequent cohorts and doses of capecitabine were escalated to 1750mg/m(2) BID. There were no DLTs at the maximum dose level of 1750mg/m(2), however, the delivered dose-intensity of capecitabine was similar at the 1750mg/m(2) dose level as the 1500mg/m(2) dose level. Therefore, the MTD was defined at 1500mg/m(2) of capecitabine in this dosing schedule with PHY906. One patient achieved a partial response, and 13 patients had stable disease that lasted more than six weeks.

CONCLUSION

The MTD of capecitabine was determined to be 1500mg/m(2) BID administered in a 7/7 schedule, in combination with PHY906 800mg BID on days 1-4. This combination was well tolerated and warrants further study.

Deformation mechanisms and impact attenuation characteristics of thin-walled collapsible air chambers used in head protection

Head injuries are a major cause of morbidity and mortality worldwide, many resulting from sporting activities. There is a constant need in the head protection industry for improved methods to manage impacts and to reduce the risk of mild and severe head injuries. Contemporary head protection primarily consists of foam with several inherent disadvantages, including a limited ability to provide effective energy absorption under both low and high impact velocities. Recently, thin-walled collapsible chambers were engineered to address this problem and have been implemented into sport helmets. The chambers consist of four engineering elements which define their dynamic performance: geometry, air volume, material, and venting system. This research analysed the contribution of air flow through an orifice to the chamber's management of impact energy. The objective of this study was to determine the effect of the chamber's vent diameter and material stiffness on peak force and venting rate during an impact. Two material stiffnesses (thermoplastic polyurethane 45D and thermoplastic polyurethane 90A) and five vent diameters (1 mm, 2 mm, 3 mm, 4 mm, and 5 mm) were tested at three inbound velocities (1.3 m/s, 2.3 m/s, and 3.0 m/s). Each chamber was impacted ten times using a monorail drop system. Analysis of the results revealed that the material stiffness, vent diameter, and inbound velocity all had a significant effect on peak force and venting rate (p < 0.001). Under low inbound velocities the largest vent diameters transmitted a lower force than the smallest vent, while this relationship reversed at high inbound velocities. Under low velocities the air flowrate was negatively correlated and the flow duration was positively correlated to the peak force. Under high velocities, the air flowrate was positively correlated and the duration was negatively correlated to the peak force. This suggested that, under low velocities, chambers performed optimally when air was dissipated quickly, for a short duration; however, as the chamber approached a critical failure region, the increased duration and decreased velocity of air released prevented higher peak forces. This research confirmed that the differences in vent diameter and material stiffness significantly affected the impact force characteristics of engineered thin-walled collapsible chambers.

Effect of PHY906 on capecitabine (CAP)-induced diarrhea in patients with GI malignancies

e20595

Background: 15.4% of pts with GI cancers treated with CAP alone at 1250mg/m2 BID D1–14 q 3 wks (14/7) develop G3/4 diarrhea (Hoff et al. JCO, 2001). PHY906 composed of 4 herbs, Scutellaria baicalensis Georgi, Glycyrrhiza uralensis Fisch., Ziziphus jujuba Mill., and Paeonia lactiflora Palla, has been used to treat diarrhea since approximately 300AD. Preliminary studies showed synergistic activity of PHY906 with chemotherapeutics and reduction of chemotherapy-induced GI toxicities, especially chemotherapy-induced diarrhea (CID). Methods: We prospectively evaluated 44 pts treated on a clinical study with CAP plus PHY906 for diarrhea (experimental arm) and compared to historical data by Hoff et al., CAP 14/7 alone arm (control arm). Experimental arm consisted of pts with refractory solid tumors in phase I and gemcitabine-refractory advanced pancreatic cancer (APC) in phase II. Ph I pts received PHY906 800mg BID D1–4 with escalating doses of CAP (1000mg/m2→1250mg/m2→1500 mg/m2→1750mg/m2 BID) D1 -7 q 2 wks (7/7), until MTD. Ph II treated pts with APC at 1500 mg/m2 and PHY906 800mg BID D1–4. Toxicity was assessed per NCI-CTCAE-v3.0. In addition, correlative chemokine (IL-2, IL-4, IL-5, etc) levels will be quantified by cytometric bead array. Results: 44 pts (30M/14F; median 64yr) received 209 cycles (median:3, r:<1–14) of PHY906 in the four CAP-7/7 escalation cohorts in Phase I (19 pts), then at the MTD of 1500mg/m2 BID in Phase II (25 pts). Phase I pts had GI malignancies; 15 (63%) had APC and 6 (25%) colorectal. Of all phase I and phase II pts, G3/4 diarrhea was observed in 5 (11.4%) pts, without G3/4 constipation. One pt with APC who received 3 cycles at the 1500mg/m2 dose level was diarrhea-free until he was removed from the study; he continued on single-agent CAP at 1000mg/m2 BID and developed G3 diarrhea. Conclusions: In this study, G3/4 diarrhea was reduced by 19.5% in pts treated with PHY906 (experimental arm) when combined with CAP 7/7 compared to historical controls (control arm). As an underlying mechanism of CID may include cytokine activation, evalation of cytokines is ongoing.

[Table: see text]

A phase II study of capecitabine (CAP) plus PHY906 in patients (pts) with advanced pancreatic cancer (APC)

e15508

Background: Gemcitabine (G) is regarded as the standard treatment for pts with APC. However, a standard second-line chemotherapy regimen has yet to be defined after G. PHY906, a 4-herb traditional Chinese medicine has a history of > 1,800 yrs of human use to treat GI symptoms including diarrhea. Preclinical studies showed that PHY906 may potentiate antitumor activity of CAP in human PANC-1 xenograft (ASCO 2007). A phase I study showed that CAP can be escalated up to 1750 mg/m2 PO BID on d1- 7 and PHY906 800mg PO BID on d1–4 q 2 wks with no DLTs (ASCO, 2008). Delivered dose-intensity of CAP was similar at 1750mg/m2 dose level as 1500mg/m2. Therefore, 1500mg/m2 of CAP and PHY906 was further tested in a phase II study as second-line treatment in pts with APC. Methods: Pts with G-refractory APC with ECOG PS <2 were treated with CAP 1500mg/m2 d1–7 with PHY906 800mg d1–4 q 2 wks. Response was assessed by CT scan according to RECIST q 6 wks and toxicity according to NCI-CTC v3.0. Primary objective is overall survival. Secondary objectives include overall RR, PFS and measurement of cytokines to assess inhibition of NF-kappa B, a possible mechanism responsible for PHY906's pharmacological activity. Results: As of January 5, 2009, 25 pts have been enrolled. Baseline characteristics include median age, 65 (range, 40–85); male/female,15/10; ECOG PS 0/1, 4/19; median cycles: 3 (r: 0.5–15). At this point 5 pts are still in active treatment. 4 pts have confirmed OS > 6 ms (1 still on study) with 2 further pts approaching 6 ms. Among evaluable pts, 1 had PR (5.3%), 11 SD (57.9%) and 7 PD (36.8%) after initial restaging scan. 36 % pts had >30% reduction in CA19–9 as biochemical response. There were 7 deaths on/within 30 days of study treatment, 6 related to PD and 1 had acute MI. G3/4 toxicities diarrhea 3/25 (12%), fatigue, 1/25 (4%), HFS 1/25 (4%) and mucositis 1/25 (4%). 1 pt was removed from study due to G3 HFS. Biomarker studies (IL4, GM-CSF, TNF-alpha, IL10, MCP-1, IL2, IL6) are ongoing. Conclusions: This is the first clinical study to evaluate a botanical formulation PHY906 with CAP in G-refractory APC pts. CAP + PHY906 regimen appears a safe and feasible salvage therapy in APC and warrants further investigation. In addition, PHY906 may have a cytoprotective antidiarrheal and anti-HFS effect, making treatment with CAP more tolerable.

[Table: see text]

New and Emerging Concepts in Travel Medicine

The following article summarises the proceedings of the Travel Medicine Study Day run by the Haywood Club Tri-Service Medical Society at the Medical Society of London on 23 November 2006. The event was attended by over 50 serving and retired DMS personnel, including nurses, MSO's and medical officers and included talks on the historical contribution of the military medical services to the evolution of tropical medicine, the changing face of worldwide illness and insights into the behaviour of travellers that may increase their risk of illness.

Bone marrow transplantation from partially HLA-mismatched family donors for acute leukemia: single-center experience of 201 patients

Between February 1993 and December 1999, 201 patients (1-59 years old, median 23) with acute leukemia (67% not in remission) underwent ex vivo T-cell-depleted (TCD) bone marrow transplants (BMT) from partially mismatched related donors (PMRD; 92% mismatched for 2-3 HLA A, B, DR antigens). Conditioning comprised total body irradiation, cyclophosphamide, cytarabine, etoposide, anti-thymocyte globulin (ATG), and methylprednisolone. Graft-versus-host disease (GVHD) prophylaxis comprised partial TCD with OKT3 (n=143) or T10B9 (n=58), steroids, ATG, and cyclosporine. The engraftment rate was 98%. The cumulative incidences of grades II-IV acute GVHD and chronic GVHD were 13 and 15%, respectively. The 5-year cumulative incidences of relapse and transplant-related mortality (TRM) were 31 and 51%, respectively. The actuarial 5-year overall survival (OS) and disease-free survival (DFS) probabilities were 19 and 18%, respectively. Patient age >15 years, active disease at transplant, donor age >25 years, and 3-antigen donor mismatch (host-versus-graft) affected the outcome adversely. The actuarial 5-year OS of four groups of patients identified based upon these risk factors was 39, 20, 13, and 0%, respectively (P<0.0001). We conclude that PMRD BMT is a potential treatment option for patients with high-risk acute leukemia who require an alternative donor transplant and fall into a group with a reasonable expected outcome.

Antimicrobial activity of some Hypericum species

The crude methanolic extracts of six species of Hypericum [H. caprifoliatum Cham. & Schlecht., H. carinatum Griseb., H. connatum Lam., H. ternum A. St. Hil., H. myrianthum Cham. & Schlecht. and H. polyanthemum Klotzsch ex Reichardt] growing in southern Brazil were analyzed for antimicrobial activity against several microorganisms (bacteria and fungi). The most active plant was H. caprifoliatum, which showed activity against Staphylococcus aureus. Only H. polyanthemum and H. ternum extracts were active against Bacillus subtilis. None of the crude methanolic extracts showed activity against S. epidermidis, Escherichia coli or Saccharomyces cerevisiae. Extracts from these species were evaluated chemically and tannin, flavonoid and phenolic acids were the prominent compounds. The plants contained quercitrin, hyperoside (except H. connatum) and, less frequently, isoquercitrin and chlorogenic acid. In contrast to H. perforatum, which has high concentrations of rutin, these species do not produce this flavonoid or it appears as traces. The tannin concentration varied between 5.1 and 16.7% in H. myrianthum and H. ternum, respectively.

Assessment of G-CSF stimulated BM hematopoietic stem cells in normal donors

BACKGROUND

The clinical use of G-CSF has recently been expanded to include mobilization of stem cells for both autologous and allogeneic transplantation. Most of the published studies have focused on stem cells released into the peripheral blood (PB) after G-CSF treatment. However, little is known about the effects of G-CSF on BM. This study evaluated the concurrent effects of short-term G-CSF on both BM and PB stem and progenitor cells in normal individuals.

METHODS

Volunteers received 5 or 10 microg/kg of G-CSF for 5 consecutive days (Days 1-5). On Days 0, 3, 6, 9 and 15, BM and PB samples were obtained. Flow cytometry and functional assay were performed to analyze stem cells, subpopulations, adhesion molecules, colony-forming units and LTCIC.

RESULTS

The total nucleated cells and absolute numbers of CD34(+)/mL showed a similar response pattern in both BM and PB, with a peak around Day 6 that returned to baseline levels by Day 15. However, there was a reciprocal change in the percentage of CD34(+) cells between BM and PB compartments. The expressions of adhesion molecule showed an up- and down-regulation of alpha4 and alpha5 integrin subunits, respectively, also correlated with the CD34(+) mobilization patterns.

DISCUSSIONS

The functional characterization of integrins, and further clinical examination of G-CSF-stimulated BM is warranted. G-CSF-stimulated BM maybe considered as an alternative source of stem cells in transplantation.

The effect of swabs soaked in bupivacaine and epinephrine for pain relief following simple dental extractions in children

We studied 133, ASA I or II children, aged 5-12 years undergoing general anaesthesia for simple dental extractions. Induction and maintenance of anaesthesia were achieved using sevoflurane in nitrous oxide and oxygen. At the end of surgery, patients had swabs soaked in a trial solution placed over the exposed teeth sockets. The bupivacaine group had swabs soaked in bupivacaine 0.25% with epinephrine 1:200 000, the saline group had swabs soaked in saline. Pain scores were recorded on a 4-point scale as follows: 0 = I don't hurt at all; 1 = I hurt a bit; 2 = I hurt a lot; 3 = I hurt the most. Nurse pain assessments and the patient's own scores were recorded at 15 and 30 min following recovery from anaesthesia. The median pain scores (2 at 15 min and 1 at 30 min postoperatively) were the same in both groups.

Long-term entecavir treatment results in sustained antiviral efficacy and prolonged life span in the woodchuck model of chronic hepatitis infection

Entecavir (ETV) is a guanosine nucleoside analogue with potent antiviral efficacy in woodchucks chronically infected with woodchuck hepatitis virus. To explore the consequences of prolonged virus suppression, woodchucks received ETV orally for 8 weeks and then weekly for 12 months. Of the 6 animals withdrawn from therapy and monitored for an additional 28 months, 3 had a sustained antiviral response and had no evidence of hepatocellular carcinoma (HCC). Of the 6 animals that continued on a weekly ETV regimen for an additional 22 months, 4 exhibited serum viral DNA levels near the lower limit of detection for >2 years and had no evidence of HCC. Viral antigens and covalently closed circular DNA levels in liver samples were significantly reduced in all animals. ETV was well tolerated, and there was no evidence of resistant variants. On the basis of historical data, long-term ETV treatment appeared to significantly prolong the life of treated animals and delay the emergence of HCC.

Isolation and expansion of cytomegalovirus-specific cytotoxic T lymphocytes to clinical scale from a single blood draw using dendritic cells and HLA-tetramers

Cytomegalovirus (CMV) reactivation in immunocompromised recipients of allogeneic stem cell transplantation is a cause of morbidity and mortality from viral pneumonitis. Antiviral drugs given to reactivating patients have reduced the mortality from CMV but have toxic side effects and do not always prevent late CMV disease. Cellular immunotherapy to prevent CMV disease is less toxic and could provide prolonged protection. However, a practical approach to generating sufficient quantities of CMV-specific cytotoxic T cells (CTLs) is required. This study describes a system for generating sufficient CMV-specific CTLs for adoptive immunotherapy of HLA-A*0201 bone marrow transplant recipients from 200 mL donor blood. Donor monocytes are used to generate dendritic cells (DCs) in medium with autologous plasma, interleukin 4, granulocyte-macrophage colony-stimulating factor, and CD40 ligand. The DCs are pulsed with the immunodominant HLA-A*0201-restricted CMV peptide pp65(495-503), and incubated with donor T cells. These cultures are restimulated twice with peptide-pulsed lymphoblastoid cell lines (LCLs) or CD40-ligated B cells and purified with phycoerythrin (PE)-labeled pp65(495-503)/HLA-A*0201 tetramers by flow sorting, or with anti-PE paramagnetic beads. The pure tetramer-positive population is then rapidly expanded to obtain sufficient cells for clinical immunotherapy. The expanded CTLs are more than 80% pure, of memory phenotype, with a Tc1 cytokine profile. They efficiently kill CMV-infected fibroblasts and express the integrin VLA-4, suggesting that the CTLs could cross endothelial barriers. This technique is reproducible and could be used for generating CMV-specific CTLs to prevent CMV disease after allogeneic blood and marrow transplantation. (Blood. 2001;98:505-512)

In vitro generation of Epstein-Barr virus-specific cytotoxic T cells in patients receiving haplo-identical allogeneic stem cell transplantation

Use of a partially mismatched related donor (PMRD) is an option for patients who require allogeneic transplantation but do not have a matched sibling or unrelated donor. Epstein-Barr virus (EBV)-induced lymphoma is a major cause of mortality after PMRD transplantation. In this study, we present a clinical grade culture system for donor-derived EBV-specific cytotoxic T cells (CTLs) that do not recognize haplo-identical recipient cells. The EBV-specific CTLs were tested for cytolytic specificity and other functional properties, including ability to transgress into tissues, propensity for apoptosis, degree of clonality, stability of dominant T-cell clones, and Tc and Th phenotypes. The EBV-specific CTLs were routinely expanded to greater than 80 x 10(6) over a period of 5 weeks, which is sufficient for clinical application. A CD8+ phenotype predominated, and the CTLs were highly specific for donor lymphoblastoid cell lines (LCLs) without killing of recipient targets or K562. Vbeta spectratyping showed an oligoclonal population that was stable on prolonged culture. The EBV-specific CTLs were activated (D-related human leukocyte antigen [HLA-DR+], L-selectin+/-) and of memory phenotype (CD45RO+). Expression of the integrin VLA-4 suggested that these CTLs could adhere to endothelium and migrate into tissues. The Bcl-2 message was upregulated, which may protect the CTLs from the apoptosis. The first demonstration of overexpression of bcl-2 in human memory CTLs. In addition, we show that lymphoblastoid cell lines used to generate CTLs are readily genetically modified with recombinant lentivirus, indicating that genetically engineered antigen presentation is feasible.

Antiviral efficacy of lobucavir (BMS-180194), a cyclobutyl-guanosine nucleoside analogue, in the woodchuck (Marmota monax) model of chronic hepatitis B virus (HBV) infection

Lobucavir (BMS-180194), a cyclobutyl-guanosine nucleoside analogue, effectively reduced WHV-viremia in chronically infected carrier woodchucks (Marmota monax) by daily per os treatment. WHV-viremia in the animals was measured by the serum content of hybridizable WHV-genomic DNA. Lobucavir, given at daily doses of 10 and 20 mg/kg body weight, reduced WHV-viremia by a 10- to 200-fold range during therapy. Lobucavir, given at 5 mg/kg, suppressed WHV-viremia by a 10- to 30-fold range, whereas a 0.5 mg/kg dose had no significant effect. WHV-viremia was also measured by hepadnaviral endogenous polymerase activity (EPA) in sera of animals treated for 6 weeks at 5 and 0.5 mg/kg. Changes in EPA in sera of lobucavir treated animals were comparable to changes in WHV DNA levels. Viremia in treated carriers recrudesced to pretreatment levels by 2 weeks of therapy cessation. These results indicated that the minimally effective antiviral daily per os dose of lobucavir in WHV-carrier woodchucks was approximately 5 mg/kg.

Follow-up recommendations for patients with American Joint Committee on Cancer Stages I-III malignant melanoma

BACKGROUND

Guidelines for follow-up of melanoma patients are not established. In 1987, a follow-up protocol was instituted at the Yale Melanoma Unit to improve upon the detection of disease recurrence in patients with American Joint Committee on Cancer Stage I-III cutaneous melanoma. The follow-up protocol consists of a patient education program and a surveillance schedule based on stage of disease.

METHODS

The authors retrospectively reviewed the records of 373 patients who were seen and followed according to the surveillance protocol in the Yale Melanoma Unit between January 1988 and December 1994 to determine 1) the time interval between the initial visit and recurrence; 2) the most common method of detecting recurrences; 3) whether the surveillance schedule or the patient detects more recurrences, i.e., asymptomatic recurrences versus symptomatic recurrences; 4) whether there is any survival difference between asymptomatic and symptomatic recurrences.

RESULTS

The 5-year overall survival rates for Stage I, II, and III patients were 95%, 72%, and 52%, respectively. Of the 78 recurrences, 44 (56%) were detected by physician-directed surveillance examinations and 34 (44%) by patients. Most recurrences were found within the first (47%) or second (32%) year of follow-up. The estimated 6-month hazard rates for death or recurrence were 0.0044, 0.0088, and 0.0278 for Stage I, II, and III patients, respectively. The group of asymptomatic patients with recurrence had a survival advantage over the symptomatic recurrence group. In addition, patients with locoregional recurrence had better survival than those with distant recurrence.

CONCLUSIONS

Although many recurrences arise rapidly and are recognized early by patients, in this study more than half were found by surveillance examinations before symptoms were manifest. Based on the hazard ratio for recurrences, the authors recommend the following surveillance schedules in addition to the patient education program for detection of recurrences: 1) Stage I, annually; 2) Stage II, every 6 months for Years 1-2 and annually thereafter; 3) Stage III, every 3 months for Year 1, every 4 months for Year 2, and every 6 months for Years 3-5; 4) at Year 6 and beyond, all patients should have surveillance annually, due to the risk of late recurrence and/or metachronous multiple primaries.

Efficacy of the carbocyclic 2'-deoxyguanosine nucleoside BMS-200475 in the woodchuck model of hepatitis B virus infection

Daily oral treatment with the cyclopentyl 2'-deoxyguanosine nucleoside BMS-200475 at doses ranging from 0.02 to 0.5 mg/kg of body weight for 1 to 3 months effectively reduced the level of woodchuck hepatitis virus (WHV) viremia in chronically infected woodchucks as measured by reductions in serum WHV DNA levels and endogenous hepadnaviral polymerase activity. Within 4 weeks of daily therapy with 0.5 or 0.1 mg of BMS-200475 per kg, endogenous viral polymerase levels in serum were reduced about 1,000-fold compared to pretreatment levels. Serum WHV DNA levels determined by a dot blot hybridization technique were comparably decreased in these treated animals. In the 3-month study, the sera of animals that had undetectable levels of WHV DNA by the dot blot technique were further analyzed by a highly sensitive semiquantitative PCR assay. The results indicate that BMS-200475 therapy reduced mean WHV titers by 10(7)- to 10(8)-fold, down to levels as low as 10(2) to 10(3) virions/ml of serum. Southern blot hybridization analysis of liver biopsy samples taken from animals during and after BMS-200475 treatment showed remarkable reductions in the levels of WHV DNA replicative intermediates and in the levels of covalently closed circular viral DNA. WHV viremia in BMS-200475-treated WHV carriers eventually returned to pretreatment levels after therapy was stopped. These results indicate that BMS-200475 should be evaluated in clinical trials for the therapy of chronic human hepatitis B virus infections.