Same-day discharge robot-assisted laparoscopic prostatectomy: feasibility, safety and patient experience.

OBJECTIVES: To report a single centre's experience of the feasibility, safety and patient acceptability of same-day discharge robot-assisted laparoscopic prostatectomy (RALP). SUBJECTS/PATIENTS AND METHODS: Between June 2015 and December 2021, a total of 180 pre-selected consecutive patients underwent RALP with the intention to discharge on the same day as surgery. Cases were performed by two surgeons. An enhanced recovery after surgery (ERAS) programme was used. The feasibility of same-day discharge was analysed, along with the complication rate, oncological outcomes, and postoperative patient experience. RESULTS: Of 180 patients, 169 (93.8%) were successfully discharged on the same day as surgery. The median (range) age was 63 ( 44-74) years. The median (range) console time was 97 (61-256) min and blood loss was 200 (20-800) mL. The resection specimen pathology results were: pT2 69.4%, pT3a 24.4% and pT3b 6.5%. With regard to Gleason Grade Group (GGG), 25.9% had GGG 1, 65.7% had GGG 2-3 and 8.4% had GGG 4-5 disease. Positive surgical margins were present in 25 cases (14.7%), 18 (15.5%) of which occurred in pT2 cases, and seven (13.4%) in pT3 cases. There were no early (<90 days) biochemical relapses (defined as prostate-specific antigen level >0.2 ng/mL). The 30-day readmission rate was 3%. A total of 13 early (0-30 days) complications were observed, five of which were Clavien-Dindo grade ≥3, however, none of these would have been avoided had the patient remained in hospital on the first postoperative night. Of 121 consecutive patients, 107 (88%) returned a satisfaction questionnaire, and 92% of responders stated they preferred recovery at home, with 94% stating they felt ready to go home. CONCLUSION: Robot-assisted laparoscopic prostatectomy combined with an ERAS programme allows patients to be safely discharged home on the same day of their surgery. This is a feasible option, well-liked by patients, with morbidity and oncological outcomes similar to non-day-case or 23 h stay RALP.

Pharmacokinetics and Safety Study of HN0037, a Novel Anti-Human Herpes Simplex Virus Inhibitor, in Healthy Volunteers.

HN0037 is a helicase-primase inhibitor developed to treat herpes simplex virus (HSV) infection. This study evaluated the safety, tolerability, and pharmacokinetics of HN0037, following oral administration in healthy volunteers. This double-blind, placebo-controlled, phase 1 study comprised two parts. In part 1, a single escalating dose of 10, 30, 60, 120, 200, 300, and 400 mg was assessed, and the food effect was evaluated in the 200-mg cohort. In part 2, a multiple dose evaluation involving 30 and 100 mg once a day was conducted for 14 days. Following single oral doses, the systemic exposure of HN0037 increased in a proportional manner over the lower dose range (10-120 mg) and in a subproportional manner over the higher dose range (200-400 mg). Following multiple oral doses, significant drug accumulation of systemic exposure was found at steady state, and the half-life ranged 50.4-61.0 h. The food effect study results indicated that a high-fat meal had a marginal impact on HN0037's pharmacokinetics. No differences were observed in the incidence of adverse events between HN0037 and placebo groups in either study. These results demonstrate that HN0037 is safe and well-tolerated, supporting further clinical development.

Major Urological Cancer Surgery for Patients is Safe and Surgical Training Should Be Encouraged During the COVID-19 Pandemic: A Multicentre Analysis of 30-day Outcomes.

COVID-19 has resulted in the deferral of major surgery for genitourinary (GU) cancers with the exception of cancers with a high risk of progression. We report outcomes for major GU cancer operations, namely radical prostatectomy (RP), radical cystectomy (RC), radical nephrectomy (RN), partial nephrectomy (PN), and nephroureterectomy performed at 13 major GU cancer centres across the UK between March 1 and May 5, 2020. A total of 598 such operations were performed. Four patients (0.7%) developed COVID-19 postoperatively. There was no COVID-19-related mortality at 30 d. A minimally invasive approach was used in 499 cases (83.4%). A total of 228 cases (38.1%) were described as training procedures. Training case status was not associated with a higher American Society of Anesthesiologists (ASA) score (p = 0.194) or hospital length of stay (LOS; p > 0.05 for all operation types). The risk of contracting COVID-19 was not associated with longer hospital LOS (p = 0.146), training case status (p = 0.588), higher ASA score (p = 0.295), or type of hospital site (p = 0.303). Our results suggest that major surgery for urological cancers remains safe and training should be encouraged during the ongoing COVID-19 pandemic provided appropriate countermeasures are taken. These real-life data are important for policy-makers and clinicians when counselling patients during the current pandemic. PATIENT SUMMARY: We collected outcome data for major operations for prostate, bladder, and kidney cancers during the COVID-19 pandemic. These surgeries remain safe and training should be encouraged during the ongoing pandemic provided appropriate countermeasures are taken. Our real-life results are important for policy-makers and clinicians when counselling patients during the COVID-19 pandemic.

Three wound-dressing strategies to reduce surgical site infection after abdominal surgery: the Bluebelle feasibility study and pilot RCT.

BACKGROUND: Surgical site infection (SSI) affects up to 20% of people with a primary closed wound after surgery. Wound dressings may reduce SSI. OBJECTIVE: To assess the feasibility of a multicentre randomised controlled trial (RCT) to evaluate the effectiveness and cost-effectiveness of dressing types or no dressing to reduce SSI in primary surgical wounds. DESIGN: Phase A - semistructured interviews, outcome measure development, practice survey, literature reviews and value-of-information analysis. Phase B - pilot RCT with qualitative research and questionnaire validation. Patients and the public were involved. SETTING: Usual NHS care. PARTICIPANTS: Patients undergoing elective/non-elective abdominal surgery, including caesarean section. INTERVENTIONS: Phase A - none. Phase B - simple dressing, glue-as-a-dressing (tissue adhesive) or 'no dressing'. MAIN OUTCOME MEASURES: Phase A - pilot RCT design; SSI, patient experience and wound management questionnaires; dressing practices; and value-of-information of a RCT. Phase B - participants screened, proportions consented/randomised; acceptability of interventions; adherence; retention; validity and reliability of SSI measure; and cost drivers. DATA SOURCES: Phase A - interviews with patients and health-care professionals (HCPs), narrative data from published RCTs and data about dressing practices. Phase B - participants and HCPs in five hospitals. RESULTS: Phase A - we interviewed 102 participants. HCPs interpreted 'dressing' variably and reported using available products. HCPs suggested practical/clinical reasons for dressing use, acknowledged the weak evidence base and felt that a RCT including a 'no dressing' group was acceptable. A survey showed that 68% of 1769 wounds (727 participants) had simple dressings and 27% had glue-as-a-dressing. Dressings were used similarly in elective and non-elective surgery. The SSI questionnaire was developed from a content analysis of existing SSI tools and interviews, yielding 19 domains and 16 items. A main RCT would be valuable to the NHS at a willingness to pay of £20,000 per quality-adjusted life-year. Phase B - from 4 March 2016 to 30 November 2016, we approached 862 patients for the pilot RCT; 81.1% were eligible, 59.4% consented and 394 were randomised (simple, n = 133; glue, n = 129; no dressing, n = 132); non-adherence was 3 out of 133, 8 out of 129 and 20 out of 132, respectively. SSI occurred in 51 out of 281 participants. We interviewed 55 participants. All dressing strategies were acceptable to stakeholders, with no indication that adherence was problematic. Adherence aids and patients' understanding of their allocated dressing appeared to be key. The SSI questionnaire response rate overall was 67.2%. Items in the SSI questionnaire fitted a single scale, which had good reliability (test-retest and Cronbach's alpha of > 0.7) and diagnostic accuracy (c-statistic = 0.906). The key cost drivers were hospital appointments, dressings and redressings, use of new medicines and primary care appointments. LIMITATIONS: Multiple activities, often in parallel, were challenging to co-ordinate. An amendment took 4 months, restricting recruitment to the pilot RCT. Only 67% of participants completed the SSI questionnaire. We could not implement photography in theatres. CONCLUSIONS: A main RCT of dressing strategies is feasible and would be valuable to the NHS. The SSI questionnaire is sufficiently accurate to be used as the primary outcome. A main trial with three groups (as in the pilot) would be valuable to the NHS, using a primary outcome of SSI at discharge and patient-reported SSI symptoms at 4-8 weeks. TRIAL REGISTRATION: Phase A - Current Controlled Trials ISRCTN06792113; Phase B - Current Controlled Trials ISRCTN49328913. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 39. See the NIHR Journals Library website for further project information. Funding was also provided by the Medical Research Council ConDuCT-II Hub (reference number MR/K025643/1).

Wound infections are common after surgery. Some are cured with simple treatment, but others may lead to serious problems. Reducing the risk of a wound infection is important. We do not know if the type of dressing, or not using a dressing, influences the risk of infection. A study that allocated patients to receive different dressings (or no dressing) would answer this question. We did preliminary research to explore whether or not such a study is possible. We interviewed doctors, nurses and patients about their views on dressings and a future study. We also described dressings currently being used in the NHS and found that simple dressings and tissue adhesive (glue) 'as-a-dressing' are used most frequently. We studied existing evidence and interviewed experts to develop a questionnaire, completed by patients, to identify wound infections after patients leave hospital and tested its accuracy. We also explored taking photographs of wounds. We investigated whether or not a major study would be worth the cost and designed a pilot study to test its feasibility. The pilot study recruited 394 patients undergoing abdominal operations in five NHS hospitals. These patients were allocated to have a simple dressing, glue-as-a-dressing or no dressing, and 92% received the allocated dressing method. Patients and their doctors and nurses found the dressing methods to be acceptable. We showed that the new patient questionnaire accurately identified infections. Patients or their carers also found it acceptable to photograph their wounds. Our research suggests that a future large study would be worth the investment and is possible.

Guidance for elective single-embryo transfer should be applied to frozen embryo transfer cycles.

PURPOSE: To provide clinicians with data showing the benefits of transferring a single blastocyst in frozen embryo transfer (FET) cycles so that they may counsel their patients accordingly. METHODS: This is a closed cohort study of 678 FET cycles occurring between January 2011 and December 2017 in a private IVF laboratory and associated physicians' practice. Patients included in the analysis were less than 38 years of age at oocyte collection, had at least two vitrified blastocysts, and were undergoing their first autologous FET cycle. The patients were categorized into four groups after they had chosen either elective single-embryo transfer (eSET) or double-embryo transfer (eDET). Outcomes for eSET and eDET were compared within groups of patients having freeze-all IVF cycles (PGT-A patient vs. non-PGT-A patient) and fresh IVF transfer groups (negative outcome vs. pregnant/delivered in fresh cycle). Main outcome measures of the study were live birth, multiple pregnancy, and implantation rates. RESULTS: There were no statistically significant differences observed in live birth rates for eSET (54-62%) vs. eDET (54-66%) (P = 0.696-1.000) in the four patient groups evaluated. Multiple pregnancy rates were significantly decreased in all eSET groups (0-3%), compared with eDET groups (24-65%) (P = 0.0001-0.037). CONCLUSIONS: This data shows that transfer of a single vitrified-warmed blastocyst maintains live birth rates, while decreasing multiple pregnancies, and may become more acceptable to physicians and patients.

Ritonavir-boosted danoprevir plus peginterferon alfa-2a and ribavirin in Asian chronic hepatitis C patients with or without cirrhosis.

BACKGROUND AND AIM: Chronic hepatitis C is an important public health problem in Asia. We evaluated the safety, efficacy, and pharmacokinetics of fixed-dose ritonavir-boosted danoprevir plus peginterferon alfa-2a/ribavirin in treatment-naive Asian patients with chronic hepatitis C virus (HCV) genotype (G)1 infection. METHODS: Treatment-naive G1 patients in Taiwan, Thailand, and Korea with serum HCV-RNA level ≥ 105 IU/mL received ritonavir-boosted danoprevir 125/100 mg twice daily plus peginterferon alfa-2a/ribavirin for either 12 (noncirrhotic patients: Arm A, n = 34) or 24 weeks (cirrhotic patients: Arm B, n = 27) in this phase II open-label study. Sustained virologic response was defined as HCV-RNA < 25 IU/mL 12 weeks after end of treatment (SVR12). RESULTS: Similar SVR12 rates were achieved in Arms A (88.2%; 95% confidence interval, 73.4-95.3%) and B (88.9%; 71.9-96.2%). Most patients had G1b infection, among whom SVR12 rates in Arms A and B were 96.7% and 91.7%, respectively. The overall SVR12 rate was 94.0% in noncirrhotic Taiwanese patients (100% in the subset of G1b patients). No patients withdrew for safety reasons. Three (11%) cirrhotic patients (Arm B) experienced serious adverse events, none of which was considered to be related to treatment. No Grade 3/4 alanine aminotransferase elevations were reported. The pharmacokinetic properties of danoprevir were broadly overlapping in noncirrhotic and cirrhotic patients both on Days 1 and 14. CONCLUSIONS: Ritonavir-boosted danoprevir plus peginterferon alfa-2a/ribavirin produced sustained virologic response rates > 90% after 12 weeks' treatment in noncirrhotic and 24 weeks' treatment in cirrhotic Asian patients with G1b infection and was well tolerated. These regimens are well suited to countries where G1b predominates.

Sphygmomanometer cuffs: a potential source of infection!

We evaluated the potential pathogenic hazard of sphygmomanometer blood pressure cuffs (BPCs) in a hospital setting. Prospectively, the presence of bacterial organisms on 120 BPCs in 14 medical wards and outpatient clinics in a district general hospital in London was assessed. Swabs taken from the inner aspect of the cuffs were cultured using standard microbiological techniques. Bacterial organisms were found in 85% (102) of the 120 BPCs assessed. The highest rates of contamination were found in the outpatients department (90%). There were differences in the most common bacterial species isolated between the samples obtained from the outpatient clinics and the wards, with coagulase-negative Staphylococcus and diphtheroids being the most prevalent species in the wards and outpatient clinics, respectively. These findings highlight the necessity to eliminate this potential risk of infection.

Minority Underrepresentation in Academia: Factors Impacting Careers of Surgery Residents.

BACKGROUND: Underrepresentation of minorities within academic surgery is an ever present problem with a profound impact on healthcare. The factors influencing surgery residents to pursue an academic career have yet to be formally investigated. We sought to elucidate these factors, with a focus on minority status. METHODS: A web-based questionnaire was sent to all administered to all ACGME-accredited general surgery programs in the United States. The main outcome was the decision to pursue a fully academic versus non-academic career. Multivariable logistic regression was used to identify characteristics impacting career choice. RESULTS: Of the 3,726 residents who received the survey, a total of 1,217 residents completed it - a response rate of 33%. Forty-seven percent planned to pursue non-academic careers, 35% academic careers, and 18% were undecided. There was no association between underrepresented minority status and academic career choice (Odds Ratio = 1.0, 95% Confidence Interval 0.6 - 1.6). Among all residents, research during training (OR=4.0, 95% CI 2.7-5.9), mentorship (OR=2.1, 95% CI 1.6-2.9), and attending a residency program requiring research (OR=2.3, 95% CI 1.5-3.4) were factors associated with choosing an academic career. When the analysis was performed among only senior residents (i.e., 4th and 5th year residents), a debt burden >$150,000 was associated with choosing a non-academic career (OR=0.4, 95% CI 0.1-0.9). CONCLUSIONS: Underrepresented minority status is not associated with career choice. Intentional recruitment of minorities into research-oriented training programs, increased mentorship and research support among current minority residents, and improved financial options for minorities may increase the number choosing an academic surgical career.

Discovery of a potent and selective EGFR inhibitor (AZD9291) of both sensitizing and T790M resistance mutations that spares the wild type form of the receptor.

Epidermal growth factor receptor (EGFR) inhibitors have been used clinically in the treatment of non-small-cell lung cancer (NSCLC) patients harboring sensitizing (or activating) mutations for a number of years. Despite encouraging clinical efficacy with these agents, in many patients resistance develops leading to disease progression. In most cases, this resistance is in the form of the T790M mutation. In addition, EGFR wild type receptor inhibition inherent with these agents can lead to dose limiting toxicities of rash and diarrhea. We describe herein the evolution of an early, mutant selective lead to the clinical candidate AZD9291, an irreversible inhibitor of both EGFR sensitizing (EGFRm+) and T790M resistance mutations with selectivity over the wild type form of the receptor. Following observations of significant tumor inhibition in preclinical models, the clinical candidate was administered clinically to patients with T790M positive EGFR-TKI resistant NSCLC and early efficacy has been observed, accompanied by an encouraging safety profile.

Structure- and reactivity-based development of covalent inhibitors of the activating and gatekeeper mutant forms of the epidermal growth factor receptor (EGFR).

A novel series of small-molecule inhibitors has been developed to target the double mutant form of the epidermal growth factor receptor (EGFR) tyrosine kinase, which is resistant to treatment with gefitinib and erlotinib. Our reported compounds also show selectivity over wild-type EGFR. Guided by molecular modeling, this series was evolved to target a cysteine residue in the ATP binding site via covalent bond formation and demonstrates high levels of activity in cellular models of the double mutant form of EGFR. In addition, these compounds show significant activity against the activating mutations, which gefitinib and erlotinib target and inhibition of which gives rise to their observed clinical efficacy. A glutathione (GSH)-based assay was used to measure thiol reactivity toward the electrophilic functionality of the inhibitor series, enabling both the identification of a suitable reactivity window for their potency and the development of a reactivity quantitative structure-property relationship (QSPR) to support design.

Balapiravir plus peginterferon alfa-2a (40KD)/ribavirin in a randomized trial of hepatitis C genotype 1 patients.

INTRODUCTION: Balapiravir (R1626, RG1626) is the prodrug of a nucleoside analogue inhibitor of the hepatitis C virus (HCV) RNA-dependent RNA polymerase (R1479, RG1479). This phase 2, double-blind international trial evaluated the optimal treatment regimen of balapiravir plus peginterferon alfa-2a (40KD)/ribavirin. MATERIAL AND METHODS: Treatment-naive genotype 1 patients (N = 516) were randomized to one of seven treatment groups in which they received balapiravir 500, 1,000, or 1,500 mg twice daily, peginterferon alfa-2a (40KD) 180 or 90 µg/week and ribavirin 1,000/1,200 mg/day or peginterferon alfa-2a (40KD)/ribavirin. The planned treatment duration with balapiravir was reduced from 24 to 12 weeks due to safety concerns. RESULTS: The percentage of patients with undetectable HCV RNA was consistently higher in all balapiravir groups from week 2 to 12. However, high rates of dose modifications and discontinuations of one/all study drugs compromised the efficacy assessment and resulted in similar sustained virological response rates in the balapiravir groups (range 32-50%) and the peginterferon alfa-2a (40KD)/ribavirin group (43%). Balapiravir was discontinued for safety reasons in 28-36% of patients (most often for lymphopenia) and the percentage of patients with serious adverse events (especially hematological, infection, ocular events) was dose related. Serious hematological adverse events (particularly neutropenia, lymphopenia) were more common in balapiravir recipients. Two deaths in the balapiravir/peginterferon alfa-2a/ribavirin combination groups were considered possibly related to study medication. CONCLUSION: Further development of balapiravir for the treatment of chronic hepatitis C has been halted because of the unacceptable benefit to risk ratio revealed in this study (www.ClinicalTrials.gov NCT 00517439).

Embryo disposition: choices made by patients and donor oocyte recipients.

OBJECTIVE: To compare final embryo disposition between patients and donor oocyte recipients. DESIGN: Retrospective study. SETTING: Private infertility practice. PATIENT(S): Patients undergoing IVF with embryo cryopreservation. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Final cryopreserved embryo disposition. RESULT(S): A total of 1,262 patients using autologous oocytes had 5,417 embryos cryopreserved. A majority either used their embryos (39%) or continued storage (35%). Of 364 patients, who did not use their remaining 1,406 embryos, 77 (21%) donated 290 embryos to other infertile couples, 41 (11%) donated 160 embryos for research, and 246 (68%) discarded 956 embryos. Concurrently, 272 donor oocyte recipients had 1,233 embryos cryopreserved. A majority either used their embryos (40%) or continued storage (23%). Of 110 recipients that did not use their remaining 455 embryos, 62 (56%) donated 280 embryos to other infertile couples, 6 (6%) donated 31 embryos for research, and 42 (38%) discarded 144 embryos. CONCLUSION(S): In our patient population, a higher proportion of patients with infertility ultimately used or stored their cryopreserved embryos for future reproduction compared with donor oocyte recipients. However, recipients were much more likely to donate to other infertile couples and less likely to discard their remaining embryos compared with patients.

Sub-Saharan African randomised clinical trials into male circumcision and HIV transmission: methodological, ethical and legal concerns.

In 2007, WHO/UNAIDS recommended male circumcision as an HIV-preventive measure based on three sub-Saharan African randomised clinical trials (RCTs) into female-to-male sexual transmission. A related RCT investigated male-to-female transmission. However, the trials were compromised by inadequate equipoise; selection bias; inadequate blinding; problematic randomisation; trials stopped early with exaggerated treatment effects; and not investigating non-sexual transmission. Several questions remain unanswered. Why were the trials carried out in countries where more intact men were HIV-positive than in those where more circumcised men were HIV-positive? Why were men sampled from specific ethnic subgroups? Why were so many participants lost to follow-up? Why did men in the male circumcision groups receive additional counselling on safe sex practices? While the absolute reduction in HIV transmission associated with male circumcision across the three female-to-male trials was only about 1.3%, relative reduction was reported as 60%, but, after correction for lead-time bias, averaged 49%. In the Kenyan trial, male circumcision appears to have been associated with four new incident infections. In the Ugandan male-to-female trial, there appears to have been a 61% relative increase in HIV infection among female partners of HIV-positive circumcised men. Since male circumcision diverts resources from known preventive measures and increases risk-taking behaviours, any long-term benefit in reducing HIV transmission remains uncertain.

Physicochemical properties of the nucleoside prodrug R1626 leading to high oral bioavailability.

The nucleoside analog R1479 is a potent and highly selective inhibitor of NS5b-directed hepatitis C virus (HCV) RNA polymerase in vitro. Because of its limited permeability, lipophilic prodrugs of R1479 were screened. Selection of the prodrug involved optimization of solubility, permeability, and stability parameters. R1626 has dissociation constant, intrinsic solubility, log partition coefficient (n-octanol water), and Caco-2 permeability of 3.62, 0.19 mg/mL, 2.45, and 14.95 x 10(-6) cm/s, respectively. The hydrolysis of the prodrug is significantly faster in the Caco-2 experiments than in hydrolytic experiments, suggesting that the hydrolysis is catalyzed by enzymes in the cellular membrane. Using GastroPlus, the physical properties of R1626 successfully predict the dose dependence of the pharmacokinetics in humans previously studied. The program predicts that if the particle size of R1626 is less than 25 microm, it will be well absorbed. Prodrugs with a solubility of greater than 100 microg/mL and permeability in the Caco-2 assay greater than 3 x 10(-6) cm/s are expected to achieve a high fraction absorbed.

R1626 plus peginterferon Alfa-2a provides potent suppression of hepatitis C virus RNA and significant antiviral synergy in combination with ribavirin.

UNLABELLED: R1626, a prodrug of the hepatitis C virus (HCV) RNA polymerase inhibitor R1479, showed time-dependent and dose-dependent reduction of HCV RNA levels in a previous study. The present study evaluated the efficacy and safety of R1626 administered for 4 weeks in combination with peginterferon alfa-2a +/- ribavirin in HCV genotype 1-infected treatment-naive patients. Patients were randomized to: DUAL 1500 (1500 mg R1626 twice daily [bid] + peginterferon alfa-2a; n = 21); DUAL 3000 (3000 mg R1626 bid + peginterferon alfa-2a; n = 32); TRIPLE 1500 (1500 mg R1626 bid + peginterferon alfa-2a + ribavirin; n = 31); or standard of care (SOC) (peginterferon alfa-2a + ribavirin; n = 20). At 4 weeks HCV RNA was undetectable (<15 IU/mL) in 29%, 69%, and 74% of patients in the DUAL 1500, DUAL 3000, and TRIPLE 1500 arms, respectively, compared with 5% of patients receiving SOC, with respective mean reductions in HCV RNA from baseline to week 4 of 3.6, 4.5, 5.2, and 2.4 log(10) IU/mL. Synergy was observed between R1626 and peginterferon alfa-2a and between R1626 and ribavirin. There was no evidence of development of viral resistance. Adverse events (AEs) were mainly mild or moderate; seven patients had nine serious AEs (including one patient with one serious AE in SOC). The incidence of Grade 4 neutropenia was 48%, 78%, 39%, and 10% in DUAL 1500, DUAL 3000, TRIPLE 1500, and SOC, respectively, and was the main reason for dose reductions. CONCLUSION: A synergistic antiviral effect was observed when R1626 was combined with peginterferon alfa-2a +/- ribavirin; up to 74% of patients had undetectable HCV RNA at week 4. Dosing of R1626 was limited by neutropenia; a study of different dosages of R1626 in combination with peginterferon alfa-2a and ribavirin is underway.