Neutralizing Antibody Validation Testing and Reporting Harmonization.

Evolving immunogenicity assay performance expectations and a lack of harmonized neutralizing antibody validation testing and reporting tools have resulted in significant time spent by health authorities and sponsors on resolving filing queries. A team of experts within the American Association of Pharmaceutical Scientists' Therapeutic Product Immunogenicity Community across industry and the Food and Drug Administration addressed challenges unique to cell-based and non-cell-based neutralizing antibody assays. Harmonization of validation expectations and data reporting will facilitate filings to health authorities and are described in this manuscript. This team provides validation testing and reporting strategies and tools for the following assessments: (1) format selection; (2) cut point; (3) assay acceptance criteria; (4) control precision; (5) sensitivity including positive control selection and performance tracking; (6) negative control selection; (7) selectivity/specificity including matrix interference, hemolysis, lipemia, bilirubin, concomitant medications, and structurally similar analytes; (8) drug tolerance; (9) target tolerance; (10) sample stability; and (11) assay robustness.

Reoperative Anorectal Procedures in Patients with Anorectal Malformations - Is Bladder Function Affected?

BACKGROUND: Anorectal malformations (ARM) are associated with neurogenic bladder. The traditional surgical ARM repair is a posterior sagittal anorectoplasty (PSARP), which is believed to have a minimal effect on bladder dynamics. However, little is known about the effects of reoperative PSARP (rPSARP) on bladder function. We hypothesized that a high rate of bladder dysfunction existed in this cohort. METHODS: We performed a retrospective review of ARM patients undergoing rPSARP at a single institution from 2008 to 2015. Only patients with Urology follow-up were included in our analysis. Data was collected regarding original level of ARM, coexisting spinal anomalies and indications for reoperation. We assessed urodynamic variables and bladder management (voiding, CIC or diverted) before and after rPSARP. RESULTS: A total of 172 patients were identified, of which 85 met inclusion criteria with a median follow-up of 23.9 months (IQR, 5.9-43.8 months). Thirty-six patients had spinal cord anomalies. Indications for rPSARP included mislocation (n = 42), posterior urethral diverticulum (PUD; n = 16), stricture (n = 19) and rectal prolapse (n = 8). Within 1 year following rPSARP, 11 patients (12.9%) had a negative change in bladder management, defined as need for beginning intermittent catheterization or undergoing urinary diversion, which increased to 16 patients (18.8%) at last follow-up. Postoperative bladder management changed in rPSARP patients with mislocation (p < 0.0001) and stricture (p 0.005) but not for rectal prolapse (p 0.143). CONCLUSIONS: Patients who undergo rPSARP warrant especially close attention for bladder dysfunction as we observed a negative postoperative change in bladder management in 18.8% of our series. LEVEL OF EVIDENCE: Level IV.

Recommendations on ELISpot assay validation by the GCC.

Gene therapy, cell therapy and vaccine research have led to an increased need to perform cellular immunity testing in a regulated environment to ensure the safety and efficacy of these treatments. The most common method for the measurement of cellular immunity has been Enzyme-Linked Immunospot assays. However, there is a lack of regulatory guidance available discussing the recommendations for developing and validating these types of assays. Hence, the Global CRO Council has issued this white paper to provide a consensus on the different validation parameters required to support Enzyme-Linked Immunospot assays and a harmonized and consistent approach to Enzyme-Linked Immunospot validation among contract research organizations.

Outcomes according to channel type for continent catheterizable channels in patients undergoing simultaneous urinary and fecal reconstruction.

INTRODUCTION: When creating a continent catheterizable channel (CCC) the choice of bowel segment used as the conduit should be tempered with the morbidity associated with it. The split-appendix technique allows the creation of both a urinary and fecal CCC without the need for a bowel anastomosis. However, there is concern that by splitting the appendix there is compromise to its blood supply and may affect outcomes. We aim to compare what affect the bowel segment used for urinary and fecal CCCs has on perioperative and long-term outcomes in patients undergoing simultaneous urinary and fecal reconstruction. METHODS: A retrospective review was performed analyzing all patients that underwent simultaneous continent catheterizable urinary and fecal CCC between the years 2010-2016. Patient demographics, channel characteristics, perioperative complications and clinical success rate were analyzed. RESULTS: A total of 106 patients were identified that had simultaneous fecal and urinary CCC created at time of reconstruction. For urinary CCC, there were 64 patients (60.4%) that underwent a split-appendix technique, 27 patients (25.4%) underwent a Monti, and 15 patients (14.2%) had the appendix used only for the urinary channel. Those patients undergoing a split-appendix technique had median operative time of 447 min compared to 619 min when a Monti channel was created. The median length of hospital stay was 9 days for the split-appendix technique compared to 12 and 13 day median hospital stay when the appendix was used only for the urinary channel or a Monti was created, respectively. There was no difference seen in revision free survival of the channel following surgery of any of the channels with median follow-up of 44.5 months. However, there were more subfascial revisions of urinary CCC in those that underwent a Monti (5 patients, 18.5%) compared to other bowel segments (0 patients). CONCLUSIONS: Utilizing a split-appendix approach for creation of urinary and fecal CCCs does not affect 30-day complications or long-term revision rates compared to other established techniques. This technique minimizes the potential surgical morbidity of a bowel anastomosis and provide shorter operative times, when feasible, at time of simultaneous creation of fecal and urinary CCC.

Clinical urologic and urodynamic outcomes in patients with anorectal malformation and absent vagina after vaginal replacement.

INTRODUCTION AND OBJECTIVES: Anorectal malformations (ARMs) represent a complex spectrum of anorectal and genitourinary anomalies and a paucity of evidence is available on long-term urologic outcomes in all ARM subtypes. It was our subjective bias from being a referral center for ARM patients that the subtype of rectovestibular fistula and absent vagina had higher risk of renal and bladder abnormalities than typical rectovestibular fistula patients. Therefore, to confirm or refute our clinical suspicions, the purpose of this study was to review this specific cohort of ARM patients and describe both the clinical urological and urodynamic outcomes. METHODS: A retrospective cohort study was performed for 120 patients who were treated for ARM and vaginal replacement at our institution between 1991 and 2017. Fifteen patients with rectovestibular fistula and absent vagina were included in our review. Demographic and clinical data were abstracted from their medical records, including urodynamic findings, need for clean intermittent catheterization (CIC), urinary continence, and renal function. RESULTS: Vaginal replacement surgery was undertaken concomitantly with ARM repair in 10 of the 15 patients (67%). One patient was lost to follow up, and mean follow up postoperatively was 39 months. In all but one patient, rectum or colon was used as the substrate for vaginal replacement. Of the 15 patients, 13 had continence data available. A total of 10 patients (77%) were able to achieve social continence. Overall six patients used CIC to manage their bladder and 40% of continent patients used CIC. Urinary continence outcomes in patients who had partial vaginal replacement compared to those with total vaginal replacement did not reveal a clinically significant difference. Continence was achieved in 3/4 patients (75%) with a history of tethered cord compared to 7/9 patients (78%) without a history of tethered cord release. Urodynamics were performed postoperatively in 7 of the 157 patients (47%). Uninhibited detrusor contractions (UDCs) were present in 3 out of 7 patients, and a cystometric capacity greater than expected was noted in 4 patients. Additionally, 2 patients had end filling detrusor pressure greater than 40 cm H2O. GFR data were available for 13 of the 15 patients and (85%) were classified as chronic kidney disease (CKD) stage I or not having any significant loss of renal function. CONCLUSIONS: In this cohort of rectovestibular fistula and absent vagina, 77% reported achieving urinary continence. However CIC was employed in 40% of the patients which is higher than prior published noncloaca female ARM patient population. Urodynamic abnormalities were noted when performed and led to change in bladder management. Renal function measured with GFR was normal in 85%. Patients with rectovestibular fistula and absent vagina benefit from urologic screening given higher rates of lower urinary tract dysfunction that can require CIC to protect the upper urinary tract and achieve urinary continence. TYPE OF STUDY: Case series. LEVEL OF EVIDENCE: Level IV.

Need for botulinum toxin injection and bladder augmentation after isolated bladder outlet procedure in pediatric patients with myelomeningocele.

INTRODUCTION: In patients with neurogenic bladder outlet incompetence, a bladder outlet procedure (BOP) may be required to achieve urinary continence. However, when performed in isolation, a BOP can be associated with bladder deterioration and upper-tract injury. In the event of bladder deterioration, additional procedures such as bladder augmentation (BA) or botulinum toxin injection (BTI) may be pursued. OBJECTIVE: The aim of this study was to assess long-term outcomes after isolated BOP in a pediatric myelomeningocele (MMC) population, including the need for additional surgical intervention in the form of BTI or BA. MATERIALS AND METHODS: A retrospective cohort study was performed for patients with MMC who underwent an isolated BOP between 2004 and 2017. Primary outcomes included the need for postoperative BTI or BA. Secondary outcomes included the association between preoperative urodynamic parameters and need for BTI or BA. RESULTS: BTI or BA was performed in 18 of 36 (50%) patients at a median of 17.8 months (IQR 11.2-29.3) after an isolated BOP. A median of 1 (IQR 1-3) BTI was performed in 11 (30.6%) patients. BA was performed in 9 (25%) patients, including 2 patients who previously underwent BTI. Patients who did not undergo BTI or BA after BOP had a slightly increased percentage estimated bladder capacity at the end of follow-up (107% versus 95%, p=0.42). By contrast, patients who underwent BTI or BA had a post-BOP percentage estimated bladder capacity that decreased from 112 to 70% (p < 0.001), increased maximum detrusor leak point pressure from 43 to 67 cm H2O (p = 0.01), and higher rate of de novo upper-tract changes. Unfortunately, no preoperative clinical, radiographic, or urodynamic factors predicted the need for BTI or BA. DISCUSSION: On time-to-event analysis, the risk of BTI or BA was 53% at 5 years in our cohort. Risk of these procedures was highest in the first two years after BOP. 9 of 11 (82%) patients who underwent BTI had improvement in bladder dynamics and BA was not pursued. These findings suggest that BTI provides a less-morbid alternative to BA in patients with MMC and de novo adverse bladder storage changes after an isolated BOP. CONCLUSION: The need for BTI or BA after an isolated BOP is significant in patients with MMC. BTI offers a less-invasive alternative to BA in this population.

12th GCC Closed Forum: critical reagents; oligonucleotides; CoA; method transfer; HRMS; flow cytometry; regulatory findings; stability and immunogenicity.

The 12th GCC Closed Forum was held in Philadelphia, PA, USA, on 9 April 2018. Representatives from international bioanalytical Contract Research Organizations were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The issues discussed at the meeting included: critical reagents; oligonucleotides; certificates of analysis; method transfer; high resolution mass spectrometry; flow cytometry; recent regulatory findings and case studies involving stability and nonclinical immunogenicity. Conclusions and consensus from discussions of these topics are included in this article.

Is anuria prior to pediatric renal transplantation associated with poor allograft outcomes?

INTRODUCTION: Anuria from end-stage renal disease leads to a defunctionalized bladder and may pose technical challenges at the time of renal transplantation. Anuria's effect on bladder function after renal transplantation is considered to be minimal in adults, although a paucity of evidence is available in children. The purpose of this study was to examine the effects of anuria prior to pediatric renal transplantation for ESRD due to medical renal disease on allograft outcome. METHODS: We performed a retrospective review of pediatric patients who underwent renal transplantation for medical renal disease at our institution between 2005 and 2016. Demographics and clinical data were assessed. We also compared GFR at 1 year post-transplant for medical renal patients with history of anuria and those without. RESULTS: Twenty-one patients fulfilled our inclusion criteria with median duration of anuria was 10 months. Preoperative VCUG was available in five patients and their bladder capacity was 29% of expected bladder capacity for age (range 8%-41%). Anticholinergic therapy was prescribed in six patients (28%) for a mean duration of 5 months (range 1-16 months). Comparison of GFR at 1 year post-transplant in anuria group and those without anuria showed no difference (69 vs 75 mL/min, P = 0.37). No correlation was observed between duration of anuria and post-transplant GFR. CONCLUSION: The majority of children in our pretransplant anuria cohort did not develop bladder dysfunction after renal transplantation. No difference was observed between GFR at 1 year when comparing anuric to non-anuric transplant recipients of medical renal disease etiology.

Recommendations for classification of commercial LBA kits for biomarkers in drug development from the GCC for bioanalysis.

Over the last decade, the use of biomarker data has become integral to drug development. Biomarkers are not only utilized for internal decision-making by sponsors; they are increasingly utilized to make critical decisions for drug safety and efficacy. As the regulatory agencies are routinely making decisions based on biomarker data, there has been significant scrutiny on the validation of biomarker methods. Contract research organizations regularly use commercially available immunoassay kits to validate biomarker methods. However, adaptation of such kits in a regulated environment presents significant challenges and was one of the key topics discussed during the 12th Global Contract Research Organization Council for Bioanalysis (GCC) meeting. This White Paper reports the GCC members' opinion on the challenges facing the industry and the GCC recommendations on the classification of commercial kits that can be a win-win for commercial kit vendors and end users.

11th GCC Closed Forum: cumulative stability; matrix stability; immunogenicity assays; laboratory manuals; biosimilars; chiral methods; hybrid LBA/LCMS assays; fit-for-purpose validation; China Food and Drug Administration bioanalytical method validation.

The 11th Global CRO Council Closed Forum was held in Universal City, CA, USA on 3 April 2017. Representatives from international CRO members offering bioanalytical services were in attendance in order to discuss scientific and regulatory issues specific to bioanalysis. The second CRO-Pharma Scientific Interchange Meeting was held on 7 April 2017, which included Pharma representatives' sharing perspectives on the topics discussed earlier in the week with the CRO members. The issues discussed at the meetings included cumulative stability evaluations, matrix stability evaluations, the 2016 US FDA Immunogenicity Guidance and recent and unexpected FDA Form 483s on immunogenicity assays, the bioanalytical laboratory's role in writing PK sample collection instructions, biosimilars, CRO perspectives on the use of chiral versus achiral methods, hybrid LBA/LCMS assays, applications of fit-for-purpose validation and, at the Global CRO Council Closed Forum only, the status and trend of current regulated bioanalytical practice in China under CFDA's new BMV policy. Conclusions from discussions of these topics at both meetings are included in this report.

Results of a prospective randomized control trial comparing hydrophilic to uncoated catheters in children with neurogenic bladder.

INTRODUCTION: Children with neurogenic bladder (NGB) often require a lifetime of clean intermittent catheterization (CIC), typically using uncoated catheters (UCs). Hydrophilic catheters (HCs) have lower friction than UCs with reported less damage to the urethra. The purpose of this study is to compare outcomes between these catheters. METHODS: An investigator-initiated, prospective, randomized clinical trial was conducted to compare HCs versus UCs. Children aged 2-17 years with NGB on CIC were enrolled for 1 year. Block randomization was used. Dexterity scores were obtained in those who perform self-catheterization. Outcomes were UTI, difficulty passing the catheter, urethral injury, and patient satisfaction. RESULTS: Demographic data is presented in the Table. Seventy-eight patients were enrolled. Age and gender were similar between the groups. Fifteen patients in each group performed CIC via an abdominal wall stoma. Eight and 15 patients withdrew from the UC and HC groups, respectively. The HC group overall had more problems with the catheter, mainly difficulty with handling. There were no differences for passing the catheter, pain, hematuria, or urethral injuries. There were two urinary tract infections (UTIs) in two HC patients and 17 UTIs in seven UC patients (p = 0.003). Patients with UTIs in the HC group went from 16% in the previous year to 5% during the study. Three children in the HC group had three or more UTIs in the year before enrollment and none during the study. The patients that completed the study with HC were overall satisfied and many requested to continue with the HC. CONCLUSIONS: HCs may decrease the risk of UTI in children with NGB. Urethral complications were low in both groups. Most HC patients were pleased but some found the slippery coating difficult to handle.

Comparison of the Pharmacokinetics of Ketorolac Tromethamine After Continuous Subcutaneous Infusion and Repeat Intramuscular Bolus Injections in Healthy Adult Subjects.

Ketorolac tromethamine is a nonsteroidal anti-inflammatory drug that exhibits analgesic activity with no sedative or anxiolytic properties. Twelve healthy male subjects were enrolled in a study to receive either of 2 treatments over 2 periods in an open-label, randomized, 2-way crossover design: (A) 120 mg of ketorolac tromethamine administered as a continuous subcutaneous infusion over a 24-hour period; or (B) an identical total daily dose administered as 4 intramuscular bolus injections of 30 mg each given every 6 hours (current labeled treatment regimen). The pharmacokinetic and safety profiles were evaluated for both treatments. Both modes of administration have similar values for area under the curve (AUC) and half-life (t1/2 ), suggesting that continuous subcutaneous infusion and repeated intramuscular bolus injections have similar bioavailability. The peak plasma concentration (Cmax ) was 40% lower when ketorolac was administered as a continuous subcutaneous infusion compared with repeat intramuscular bolus injections. The concentration at steady-state (Css ) for continuous subcutaneous infusion was between the Cmax and Ctrough values obtained following the 4 intramuscular injections. Both treatment arms were well tolerated.

9th GCC closed forum: CAPA in regulated bioanalysis; method robustness, biosimilars, preclinical method validation, endogenous biomarkers, whole blood stability, regulatory audit experiences and electronic laboratory notebooks.

The 9th GCCClosed Forum was held just prior to the 2015 Workshop on Recent Issues in Bioanalysis (WRIB) in Miami, FL, USA on 13 April 2015. In attendance were 58 senior-level participants, from eight countries, representing 38 CRO companies offering bioanalytical services. The objective of this meeting was for CRO bioanalytical representatives to meet and discuss scientific and regulatory issues specific to bioanalysis. The issues selected at this year's closed forum include CAPA, biosimilars, preclinical method validation, endogenous biomarkers, whole blood stability, and ELNs. A summary of the industry's best practices and the conclusions from the discussion of these topics is included in this meeting report.

Assay development for determination of tenofovir in human plasma by solid phase analytical derivatization and LC-MS/MS.

BACKGROUND: A novel method was developed and validated to measure tenofovir in human plasma. RESULTS/METHODOLOGY: This method employed solid phase analytical derivatization and analysis by LC-MS/MS. Stable-labeled internal standard was added to plasma samples followed by solid phase extraction. Retained analytes were derivatized on the solid phase extraction cartridges with a diazomethane solution to yield methyl-ester derivatives. Samples were analyzed using LC-MS/MS incorporating the use of a strong cation exchange column. The method was validated over a range of 5.00-750 ng/ml. The approach developed in this report for tenofovir could be applied to other analytes that share similar structural similarities. CONCLUSION: The tenofovir LC-MS/MS method was used to support a clinical study of over 400 samples with a 100% success rate.

Chronic Kidney Disease Stage Progression in Patients Undergoing Repair of Persistent Cloaca.

PURPOSE: Children born with persistent cloaca undergo complex pelvic reconstruction early in life. Long-term risks of bladder dysfunction and chronic kidney disease are well described. We report upper urinary tract outcomes and the risk of chronic kidney disease stage progression in this patient population. MATERIALS AND METHODS: We retrospectively studied a cohort of patients undergoing posterior sagittal anorecto-vagino-urethroplasty at a single institution from 2006 to 2013. Inclusion criteria consisted of complete urological care at our institution. Chronic kidney disease stage was calculated from cystatin C or nuclear medicine glomerular filtration rate. RESULTS: A total of 44 patients met inclusion criteria. Of the patients 12 had undergone vesicostomy or ureterostomy. A total of 19 patients had hydronephrosis, 19 had vesicoureteral reflux and 15 had a tethered spinal cord. Median length of the common channel was 3.5 cm. Median age at posterior sagittal anorecto-vagino-urethroplasty was 7.3 months. Median followup was 5.3 years. A total of 30 patients had neurogenic bladder, of whom 27 required clean intermittent catheterization and 3 had undergone vesicostomy. Of the patients 38 had stage I or II, 5 had stage III and 1 had stage IV chronic kidney disease. During followup no patient with initial stage I to III chronic kidney disease had stage progression. The patient with stage IV chronic kidney disease had a renal allograft placed at age 34 months before needing dialysis. CONCLUSIONS: Early outcomes in patients with stage I to III chronic kidney disease demonstrate that renal function can be maintained despite a high rate of lower urinary tract dysfunction. Aggressive bladder management may help prevent progressive renal injury in this population.

Endoscopic treatment with dextranomer/hyaluronic acid for persistent incontinence after continent urinary reconstruction.

PURPOSE: To determine the applicability and long-term outcome of endoscopic injection of dextranomer/hyaluronic acid (Dx/HA) to correct incontinence in patients who had previously undergone continent urinary reconstruction. PATIENTS AND METHODS: A retrospective cohort study was performed of all patients who underwent Dx/HA injection at our institution from January 2001 to June 2011. All patients had adequate bladder capacity and compliance on maximized medical therapy before injection. "Success" was defined as either "continence" (daytime dry interval >3 hours) or "improvement" (daytime dry interval >2 hours). RESULTS: A total of 22 children (16 females and 6 males) had Dx/HA injections for persistent incontinence from either bladder neck (7), Mitrofanoff (10), or both (5). Median age at injection was 13 years (range 4-21). Children underwent an average of 1.6 injection sessions per patient with an average of 2.6 mL of Dx/HA per session. At a median follow-up of 72 months (range 4-104), 19 (86.4%) patients had successful results (16 continent, 3 improved). For those incontinent from bladder neck, 42% became continent after 1, 75% after 2, and 83% after 3 injections, with a success rate of 91% (10 continent, 1 improved). For those incontinent from Mitrofanoff, 20% became continent after 1, and 73% after 2 injections, with a success rate of 86% (11 continent, 2 improved). CONCLUSIONS: Endoscopic injection of Dx/HA to correct residual incontinence in selected children after urinary reconstruction appears to be safe and effective, achieving a dry interval in more than two-thirds of patients.

Epididymitis in patients with anorectal malformations: a cause for urologic concern.

INTRODUCTION: Epididymitis in patients with anorectal malformation (ARM) represents a unique problem because unlike the general population, an underlying urinary tract problem is frequently identified. We review our experience with epididymitis in ARM population with an emphasis on examining urologic outcomes. MATERIALS AND METHODS: We performed a retrospective review of male patients with ARM cared for from 1980 to 2010. Clinical and pathologic variables recorded included age at presentation, recurrence, associated urologic anomalies, incidence of ureteral fusion with mesonephric ductal structures, glomerular filtration rate and urodynamic parameters. RESULTS: Twenty-six patients were identified with documented episodes of epididymitis. Renal injury was noted in five patients (19%), all of whom were diagnosed with neurogenic bladder (NGB) several years after anorectoplasty. NGB was found in ten patients (38%) in our series. Ectopic insertion of ureter into a mesonephric ductal structure was discovered in five patients (19%). Twelve patients (46%) had recurrent episodes of epididymitis, with seven of these patients (58%) being diagnosed with NGB. Two patients in the pubertal group presented with a history of epididymitis and complained of ejaculatory pain. CONCLUSION: Epididymitis in a patient with ARM warrants a comprehensive urologic investigation, particularly in recurrent episodes. Attempts at surgical intervention (e.g. vasectomy) should be avoided until functional assessment of the urinary tract has occurred. Failure to recognize this association may lead to potentially avoidable complications and morbidity. Long term urological follow up of these patients is warranted to identify at risk patients and minimize renal deterioration.

8th GCC: consolidated feedback to US FDA on the 2013 draft FDA guidance on bioanalytical method validation.

The 8th GCC Closed Forum for Bioanalysis was held in Baltimore, MD, USA on 5 December 2013, immediately following the 2013 AAPS Workshop (Crystal City V): Quantitative Bioanalytical Methods Validation and Implementation--The 2013 Revised FDA Guidance. This GCC meeting was organized to discuss the contents of the draft revised FDA Guidance on bioanalytical method validation that was published in September 2013 and consolidate the feedback of the GCC members. In attendance were 63 senior-level participants, from seven countries, representing 46 bioanalytical CRO companies/sites. This event represented a unique opportunity for CRO bioanalytical experts to share their opinions and concerns regarding the draft FDA Guidance, and to build unified comments to be provided to the FDA.

Quantitative analysis of bisphosphonates in biological samples.

Bisphosphonate drugs pose significant challenges for bioanalysis due to various complicating factors. In 2006, a novel approach, utilizing 'on-column' derivatization with diazomethane, was reported that revolutionized the application of liquid-chromatography-tandem mass spectrometry to bisphosphonates bioanalysis. The methodology enables superior biological sample clean-up while transforming bisphosphonates into species amenable to liquid-chromatography-tandem mass spectrometry detection. Since then, the approach has been successfully applied to numerous bisphosphonates. The use of an alternative methylation reagent - trimethylsilyl diazomethane - for on-column derivatization has been reported recently. This review focuses on published methods utilizing on-column derivatization for bioanalysis of major bisphosphonate drugs in biological matrices. Critical points required for successful application of on-column derivatization to the bioanalysis of bisphosphonates will be discussed.

Recommendations on incurred sample stability (ISS) by GCC.

The topic of incurred sample stability (ISS) has generated considerable discussion within the bioanalytical community in recent years. The subject was an integral part of the seventh annual Workshop on Recent Issues in Bioanalysis (WRIB) held in Long Beach, CA, USA, in April 2013, and at the Global CRO Council for Bioanalysis (GCC) meeting preceding it. Discussion at both events focused on the use of incurred samples for ISS purposes in light of results from a recent GCC survey completed by member companies. This paper reports the consensus resulting from these discussions and serves as a useful reference for depicting ISS issues and concerns, summarizing the GCC survey results and providing helpful recommendations on ISS in the context of bioanalytical method development and application.