Identification of seven novel HLA class I alleles in New Zealand.

Seven new HLA class I alleles have been identified in the New Zealand population in the process of routine HLA typing and they are described here. Unusual bead positivity in Luminex typing identified potential new alleles in a bone marrow registry donor (B*40:285) and two HIV patients prior to abacavir prescription (B*14:02:09, B*41:29). In addition, four new class I alleles were identified through class I sequencing-based typing (SBT) outside of exons 2 and 3. One mutation was identified in exon 4 (new allele C*12:125) and three have been found in exon 5, an exon rarely sequenced. Two stem cell transplant recipients (B*07:02:45, C*03:279) had novel mutations in exon 5 and one was found in exon 5 of a potentially matched unrelated donor from DKMS, previously thought to be B*40:02:01 (B*40:303).

The impact of playing in matches while injured on injury surveillance findings in professional football.

This study aimed to analyze the frequency, nature, and consequences of footballers playing matches while injured, and to examine the impact on injury surveillance findings. High levels of inter-rater reliability and content validity were established for a tool designed to document players who were already injured at the start of a match. The tool was implemented in three English football teams (a Championship, League 1, and League 2 team) for one season, using a "time loss" definition of injury. One hundred forty-three matches were surveyed, revealing 102 match appearances by players who were already injured. Almost half of all games featured at least one injured player, with episodes of playing with injury occurring more frequently and lasting longer in League 2 players compared with higher level players. No association was observed between the number of injured players starting matches and match outcome [χ(2) (4, N = 143) = 3.27, P = 0.514]. Fifteen percent of all injury episodes captured were only through prospective documentation of playing while injured. The findings show that both traumatic and overuse injuries are managed by footballers through competitive matches, and have important implications for aiding understanding of the epidemiology of injury in professional football.

Clinical outcomes of hemiarthroplasty and biological resurfacing in patients aged younger than 50 years.

BACKGROUND: Total shoulder arthroplasty as a treatment for glenohumeral degenerative joint disease is well accepted but has been less predictable with regard to outcomes and durability in a younger aged population, typically aged younger than 50 years. This younger population has a greater potential for glenoid component loosening. This has led surgeons to perform hemiarthroplasty or hemiarthroplasty with biological resurfacing of the glenoid in an effort to avoid the potential problems with a polyethylene glenoid and obtain durable and acceptable results for these patients. METHODS: The study included 44 patients, with 23 undergoing hemiarthroplasty alone and 21 undergoing hemiarthroplasty with biological resurfacing of the glenoid. All patients were aged younger than 50 years. Preoperative diagnoses, comorbidities, demographics, and range of motion were collected. Preoperative and postoperative radiographs were obtained. Preoperative and postoperative objective scoring measures (Single Assessment Numeric Evaluation, American Shoulder and Elbow Surgeons score, visual analog scale, Simple Shoulder Test, Constant-Murley) were used. RESULTS: Mean follow-up was 3.8 years for the hemiarthroplasty group and 3.6 years for the biological resurfacing group. Six patients in the hemiarthroplasty and 12 patients in the biological resurfacing group were considered failures due to revision surgery or an American Shoulder and Elbow Surgeons score <50. The hemiarthroplasty group had significantly better visual analog scale and Single Assessment Numeric Evaluation scores. CONCLUSIONS: There was a significant failure rate in the hemiarthroplasty and the biologic resurfacing groups compared with results in the literature. Improved outcomes and lower failure rates were observed in the hemiarthroplasty group compared with the biological resurfacing group in this study.

Using HLA loci to inform ancestry and health in Polynesian and Maori populations.

Human leukocyte antigens (HLA) are important genetic markers of tissue identity and accurately reflect ancestral history. The work reported in this paper provides a detailed description of HLA polymorphism in Polynesian and Maori individuals in relation to other populations. Our study concerns HLA classes I and II antigens in Polynesian (N = 36) and Maori (N = 114) subjects genotyped at two digit resolution by New Zealand Blood Service Laboratory in Auckland using polymerase chain reaction-sequence specific oligonucleotide and PCR-SSP technologies. We have also compared our data with those from other Austronesian-speaking Mongoloid and Papuan-speaking Australoid populations in order to test previously published account of the origin of Proto-Polynesians via gender-biassed gene flow between these two ancestral populations. We use principal coordinate analysis for this purpose, arguing this approach to be superior to tree-based methods, because of factors associated with population history and admixture. Our data are in general agreement with earlier work and reflect received wisdom on the dual origin of Proto-Polynesians. They also show the way in which the genetic make-up of Polynesian and Maori subjects is changing due to intermarriage with Europeans.

A novel HLA-B*40 sequence--B*40:92.

A new allele, HLA-B*40:92, was identified in a north-western European subject during polymerase chain reaction using sequence-specific priming (PCR-SSP)-based typing of haematopoietic stem cell (HSC) donors. B*40:92 differs from B*40:01:01 by six nucleotides at positions 559, 560, 603, 605, 610 and 618 in exon 3 which represents a substitution motif of at least 60 nucleotides. This motif, which occurs in numerous HLA alleles including the relatively high frequency B*15 and B*35 allele families, encode four amino acid changes at positions 163 (glutamic acid > leucine), 177 (aspartic acid > glutamic acid), 178 (lysine > threonine), 180 (glutamic acid > glutamine) and a silent substitution, conserved alanine, at codon 182. Thus, it is likely that HLA-B*40:92 occurred following a gene conversion-like or interallelic recombination event involving B*40:01:01 and probably a B*15 or more likely a B*35 family allele. HLA-B*40:92 was found on a haplotype with HLA-A*02:01, B*40:92, C*03:04, DRB1*13:02, DRB3*03:01, DQA1*01:02, DQB1*06:04, DPA1*02:02, DPB1*05:01. Tests on 69 selected B40 and B35 antisera and Lambda Monoclonal Trays™ show that B*40:92 encodes a 'short' B40/B60 serological specificity which displays some HLA-B35 reactivity. The HLA-B40 and HLA-B35 motifs (possible epitopes) responsible for this serological reactivity were identified. This single example of HLA- B*40:92 was found in 56,823 consecutive HLA PCR-SSP typed HSC donors indicating a carriage frequency of 0.00176% (allele frequency 0.00001) in blood donors resident in Wales. An Epstein-Barr virus transformed B-cell line from the HLA-B*40:92 donor is available.

Two new HLA-C alleles: Cw*0222 and Cw*0434.

HLA-Cw*0222 differs from Cw*020202 by three nucleotides at codons 114, 116 and 127, while HLA-Cw*0434 differs from Cw*0408 by two nucleotides at codons 152 and 156.

A new HLA-B*08 variant--B*0838.

HLA-B*0838 differs from B*080101 by three nucleotides resulting in an amino acid change of 63asparagine to 63glutamic acid and a synonymous substitution.

A new HLA-C allele: Cw*0819.

Human leucocyte antigen-Cw*0819 differs from Cw*0802 by two nucleotides resulting in an amino acid change of 99tyrosine to 99phenylalanine and a synonymous substitution.

Coding sports injury surveillance data: has version 10 of the Orchard Sports Injury Classification System improved the classification of sports medicine diagnoses?

OBJECTIVES: To compare versions 8 and 10 of the Orchard Sports Injury Classification System (OSICS) to determine whether the revised version of OSICS has improved its use in a sports medicine setting, and to assess the inter-rater reliability of OSICS-10. METHODS: Injury surveillance data, gathered over a 2 year period in professional football, cricket and rugby union to produce 335 diagnoses, were coded with both OSICS-8 and OSICS-10. Code-diagnosis agreement was assessed for OSICS-8 in terms of whether a diagnosis was codeable or noncodeable, and for OSICS-10 by evaluating the highest available OSICS-10 tier of coding. Eight clinicians coded a list of 20 diagnoses, comprising a range of pathologies to all gross anatomical regions, which were compared to assess inter-rater reliability. RESULTS: All diagnoses could be assigned an appropriate code with OSICS-10, compared with 87% of diagnoses that could be assigned an OSICS-8 code. Contusions comprised almost half of OSICS-8 noncodeable diagnoses. OSICS-10 tier 2 codes accounted for 20% of diagnoses coded with the updated system. Of these 20%, almost half contained a more detailed diagnosis that did not have an available OSICS-10 tier 3 or 4 code. Inter-rater reliability increased with decreasing diagnostic detail, with an overall level shown to be moderate (k = 0.56). CONCLUSIONS: OSICS-10 is a more encompassing system than OSICS-8 to use in classifying sports medicine diagnoses, and has a moderate level of inter-rater reliability. Further minor revision may be required to address lack of detail in some strain, effusion and contusion codes.

Validation of the integrative model of adjustment to chronic conditions: Applicability to adult-onset epilepsy.

Adapting to life with adult-onset epilepsy is a challenge and there is a need for better interventions to support people, who have difficulty with psychosocial adjustment to the condition. The integrative model of adjustment to chronic conditions was developed for type 2 diabetes. This study aimed to demonstrate the applicability of the model to adult-onset epilepsy and thus make an original contribution to the development of relevant interventions. Qualitative data from a previous phenomenological study on the experience of adult-onset epilepsy were mapped onto the integrative model of adjustment to chronic conditions using framework analysis. Ten of the original 39 datasets were selected. All 10 datasets were from females diagnosed with epilepsy within 5 years before participation in the original study. The results demonstrated applicability of the integrative model of adjustment to chronic conditions after minor revisions to the model. These findings support further development of the integrative model of adjustment to chronic conditions for use as a clinical intervention for people with adult-onset epilepsy.

A novel HLA-B*44 allele, HLA-B*4459, identified in a renal patient with aberrant B44 serology and characterized by sequence-based typing.

Human leukocyte antigen-B*4459 was first identified in a renal patient. The novel allele differs from B*44020101 by a single nucleotide change in exon 3 at nucleotide 453 (C-->G), which changes codon 127 from asparagine (AAC) to lysine (AAG) explaining some aberrant B44 serology results in 2003.

Should whole body cryotherapy sessions be differentiated between women and men? A preliminary study on the role of the body thermal resistance.

The aim of this study was to investigate how body thermal resistance between sexes evolves over time in the recovery period after a WBC session and to show how this parameter should be considered as a key parameter in WBC protocols. Eighteen healthy participants volunteered for the study (10 males and 8 females). Temperature (core and skin) were recorded pre- and post (immediately and every 5 min until 35 min post) exposure to a single bout of WBC (30 s at -60 °C, 150 s at -110 °C). From both core and skin temperatures a bio-heat transfer model was applied which led to the analytical formulation of the body thermal resistance. An unsteady behavior presenting a similar time-evolution trend in the body insulative response is shown for both females and males, possibly due to the vasodilatation process following an intense peripheral vasoconstriction during the extreme cold. Females present a 37% higher inner thermal resistance than males when reaching an asymptotical thermal state at rest due to a higher concentration of body fat percentage. Adiposity of tissues inherent in fat mass percentage appears to be a key parameter in the body thermal resistance to be taken into account in the definition of appropriate protocols for males and females. The conclusions of this preliminary study suggest that in order to achieve the same skin effects on temperature and consequently to cool efficiency tissues in the same way, the duration of cryotherapy protocols should be shorter when considering female compared to male.

Mutations in the hrp48 gene, which encodes a Drosophila heterogeneous nuclear ribonucleoprotein particle protein, cause lethality and developmental defects and affect P-element third-intron splicing in vivo.

The Drosophila melanogaster hnRNP protein, hrp48, is an abundant heterogeneous nuclear RNA-associated protein. Previous biochemical studies have implicated hrp48 as a component of a ribonucleoprotein complex involved in the regulation of the tissue-specific alternative splicing of the P-element third intron (IVS3). We have taken a genetic approach to analyzing the role of hrp48. Mutations in the hrp48 gene were identified and characterized. hrp48 is an essential gene. Hypomorphic mutations which reduce the level of hrp48 protein display developmental defects, including reduced numbers of ommatidia in the eye and morphological bristle abnormalities. Using a P-element third-intron reporter transgene, we found that reduced levels of hrp48 partially relieve IVS3 splicing inhibition in somatic cells. This is the first direct evidence that hrp48 plays a functional role in IVS3 splicing inhibition.

A high-resolution polymerase chain reaction-sequence-specific primer HLA-B*27 typing set and its application in routine HLA-B27 testing.

We designed a set of 35 polymerase chain reaction sequence-specific primers (PCR-SSP) in 29 SSP mixtures to assign 29 HLA-B*27 4-digit level alleles (B*2701-B*2721 and B*2723-B*2730). This was used in conjunction with our 41 PCR-SSP primer mixture low-resolution HLA-B typing set to fully differentiate B*27 from all other HLA-B alleles. Successful typing set validation used 521 B*27 samples covering 13 (B*2701-B*2710 and B*2712, B*2717, B*2723) alleles. The distribution of B*27 alleles was determined in a random population of 4020 local blood donors and the use of PCR-SSP B*27 typing in our routine flow cytometry-based HLA-B27/B2708 typing strategy is described.

DX-8951f, a hexacyclic camptothecin analog, on a daily-times-five schedule: a phase I and pharmacokinetic study in patients with advanced solid malignancies.

PURPOSE: To assess the feasibility of administering DX-8951f (exatecan mesylate), a water-soluble, camptothecin analog, as a 30-minute intravenous infusion daily for 5 days every 3 weeks, determine the maximum-tolerated dose (MTD) and pharmacokinetic (PK) behavior of DX-8951f, and seek preliminary evidence of anticancer activity. PATIENTS AND METHODS: Patients with advanced solid malignancies were treated with escalating doses of DX-8951f. After three patients were treated at the first dose level, doses were to be escalated in increments of 100%, using a single patient at each dose level unless moderate toxicity was observed. The MTD, defined as the highest dose level at which the incidence of dose-limiting toxicity did not exceed 20%, was calculated separately for minimally pretreated (MP) and heavily pretreated (HP) patients. The PK and excretory profiles of DX-8951, the anhydrous form of DX-8951f, were also characterized. RESULTS: Thirty-six patients were treated with 130 courses of DX-8951f at six dose levels ranging from 0.1 to 0.6 mg/m(2)/d. Brief, noncumulative neutropenia was the most common toxicity observed. Severe myelosuppression (neutropenia that was protracted and/or associated with fever and/or severe thrombocytopenia) was consistently experienced by HP and MP patients at doses exceeding 0.3 and 0.5 mg/m(2)/d, respectively. Nonhematologic toxicities (nausea, vomiting, and diarrhea) were also observed, but these effects were rarely severe. Objective antitumor activity included partial responses in one patient each with platinum-resistant extrapulmonary small-cell and fluoropyrimidine- and irinotecan-resistant colorectal carcinoma, and minor responses in patients with prostate, hepatocellular, thymic, primary peritoneal, and irinotecan-resistant colorectal carcinomas. The PKs of total DX-8951 were linear and well fit by a three-compartment model. CONCLUSION: The recommended doses for phase II studies of DX-8951f as a 30-minute infusion daily for 5 days every 3 weeks are 0.5 and 0.3 mg/m(2)/d for MP and HP patients, respectively. The characteristics of the myelosuppressive effects of DX-8951f, paucity of severe nonhematologic toxicities, and antitumor activity against a wide range of malignancies warrant broad disease-directed evaluations of DX-8951f on this schedule.

Phase I and pharmacokinetic study of the differentiating agent vesnarinone in combination with gemcitabine in patients with advanced cancer.

PURPOSE: To evaluate the maximum-tolerated dose, dose-limiting toxicities (DLTs), and pharmacokinetic profile of vesnarinone given once daily in combination with gemcitabine. PATIENTS AND METHODS: Twenty-six patients were treated with oral vesnarinone once daily on a continuous schedule at doses of 60, 90, 120, 150, and 180 mg in combination with intravenous (IV) gemcitabine at a dose of 1,000 mg/m(2) on days 1, 8, and 15 every 4 weeks. To determine whether biologically relevant concentrations were being achieved, predose concentrations (C(min)) of vesnarinone were obtained weekly. Plasma gemcitabine and 2',2'-difluorodeoxyuridine concentrations were obtained during courses 1 and 2. RESULTS: Twenty-six patients were treated with 92 courses of vesnarinone/gemcitabine. The principal toxicities of the regimen consisted of neutropenia and thrombocytopenia, which were dose-limiting in two of eight heavily pretreated new patients treated at the 90 mg/1,000 mg/m(2) dose level and one of 10 minimally pretreated new patients at the 120 mg/1,000 mg/m(2) dose level. None of three patients treated with 15 courses at the vesnarinone/gemcitabine dose levels of 60 mg/1,000 mg/m(2) experienced DLT. Pharmacokinetic studies of vesnarinone revealed significant interpatient variability at any given dose level. There was evidence of a linear relationship between vesnarinone dose and mean C(min) at dosages of vesnarinone less than 150 mg, with plateauing of mean C(min) values at higher dosages. There was no impact of vesnarinone on gemcitabine concentrations, and the vesnarinone pharmacokinetics did not change with gemcitabine between weeks 1 and 2. Two partial responses occurred in patients with refractory breast and non-small-cell lung carcinoma. CONCLUSION: When combined with gemcitabine, the recommended dose of vesnarinone for phase II evaluations is 90 mg orally once daily with gemcitabine 1,000 mg/m(2) IV on days 1, 8, and 15 every 4 weeks. There is no evidence of pharmacokinetic interaction between vesnarinone and gemcitabine. Further studies of vesnarinone as a single agent or in combination with gemcitabine and other antineoplastic agents are warranted.

Phase I and pharmacologic study of the specific matrix metalloproteinase inhibitor BAY 12-9566 on a protracted oral daily dosing schedule in patients with solid malignancies.

PURPOSE: To evaluate the feasibility of administering BAY 12-9566, a matrix metalloproteinase (MMP) inhibitor with relative specificity against MMP-2, MMP-3, and MMP-9, on a protracted oral daily dosing schedule in patients with advanced solid malignancies. The study also sought to determine the principal toxicities of BAY 12-9566, whether plasma BAY 12-9566 steady state concentrations (C(ss)) of biologic relevance could be sustained for prolonged periods, and whether BAY 12-9566 affected plasma concentrations of MMP-2, MMP-9, and tissue inhibitor of MMP-2 (TIMP-2). PATIENTS AND METHODS: Patients with solid malignancies were treated with BAY 12-9566 at daily oral doses ranging from 100 to 1,600 mg. BAY 12-9566 dose schedules included 100 mg once daily, 400 mg once daily, 400 mg twice daily, 400 mg three times daily, 400 mg four times daily, and 800 mg twice daily. Plasma was collected to study the range of BAY 12-9566 C(ss) values achieved, and exploratory studies were performed to assess the effects of BAY 12-9566 on plasma concentrations of MMP-2, MMP-9, and TIMP-2. RESULTS: Twenty-one patients were treated with 47 28-day courses of BAY 12-9566. The most common side effects were headache, nausea, vomiting, abnormalities in hepatic functions, and thrombocytopenia, which were rarely clinically significant. BAY 12-9566 was well tolerated on all dose schedules, and there was no consistent dose-limiting toxicity that precluded treatment in the range of dose schedules evaluated. Instead, dose escalation was terminated because BAY 12-9566 plasma C(ss) values increased less than proportionately and plateaued as the daily dose was increased within the dose range of 100 to 1,600 mg/d, suggesting saturable drug absorption. Mean plasma C(ss) values achieved with all dose schedules exceeded BAY 12-9566 concentrations required to inhibit MMPs in vitro and in vascular invasion and tumor proliferation in vivo models. There were no consistent effects of BAY 12-9566 on the plasma concentrations of MMP-2 and MMP-9 over the continuous dosing period at any dose schedule level. However, plasma levels of TIMP-2 seemed to increase in a dose-dependent manner (r(2) =.50, P =.046). CONCLUSIONS: The recommended dose of BAY 12-9566 for subsequent disease directed studies is 800 mg twice daily, which resulted in biologically relevant plasma C(ss) values and an acceptable toxicity profile. Although exploratory studies of MMPs in plasma were not revealing, it is conceivable that some tumor types and disease settings are more likely to produce more readily quantifiable levels of activated MMPs than others. Therefore, attempts to identify and quantify surrogate markers of MMP inhibitory effects should continue to be performed in disease-directed studies in more homogenous patient populations.

Phase I and pharmacokinetic study of temozolomide on a daily-for-5-days schedule in patients with advanced solid malignancies.

PURPOSE: To determine the principal toxicities, characterize the pharmacokinetics (PKs) and pharmacodynamics (PDs) of temozolomide (TMZ) on a daily-for-5-days schedule, and recommend a dose for subsequent disease-directed studies in both minimally pretreated (MP) and heavily pretreated (HP) patients. PATIENTS AND METHODS: Patients received TMZ as a single oral dose daily for 5 consecutive days every 28 days. TMZ doses were escalated from 100 to 150, and 150 to 200 mg/m(2)/d in separate cohorts of MP and HP patients. PK plasma was sampled on days 1 and 5. TMZ concentrations were analyzed and pertinent PK parameters were related to the principal toxicities of TMZ in PD analyses. RESULTS: Twenty-four patients were treated with 85 courses of TMZ. Thrombocytopenia and neutropenia were the principal dose-limiting toxicities (DLTs) of TMZ on this schedule. The cumulative rate of severe myelosuppressive effects was unacceptably high at TMZ doses exceeding 150 mg/m(2)/d in both MP and HP patients. TMZ was absorbed rapidly with maximum concentrations achieved in 0.90 hours, on average, and elimination was rapid, with a half-life and systemic clearance rate (Cl(S/F)) averaging 1.8 hours and 115 mL/min/m(2), respectively. When clearance was normalized to body-surface area (BSA), interpatient variability in Cl(S/F) was reduced from 20% to 13% on day 1 and from 16% to 10% on day 5. Patients who experienced DLT had significantly higher maximum drug concentration( )(median 16 v 9.5 microg/mL, P =. 0084) and area under the concentration-time curve (median 36 v 23 microg-h/mL, P =.0019) values on day 5. CONCLUSION: Prior myelosuppressive therapy was not a determinant of toxicity. TMZ 150 mg/m(2)/d administered as a single oral dose daily for 5 days every 4 weeks is well tolerated by MP and HP patients, with higher doses resulting in unacceptably high rates of severe hematologic toxicity. TMZ doses should be individualized according to BSA rather than use of a prespecified oral dose for all individuals. TMZ is an optimal agent to develop in combination with other cytotoxic, biologic, and targeted therapeutics for patients with relevant malignancies.

Phase I and pharmacokinetic study of the water-soluble dolastatin 15 analog LU103793 in patients with advanced solid malignancies.

PURPOSE: To determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLTs), and pharmacokinetic profile of the dolastatin 15 analog LU103793 when administered daily for 5 days every 3 weeks. PATIENTS AND METHODS: Fifty-six courses of LU103793 at doses of 0.5 to 3.0 mg/m2 were administered to 26 patients with advanced solid malignancies. Pharmacokinetic studies were performed on days 1 and 5 of course one. Pharmacokinetic variables were related to the principal toxicities. RESULTS: Neutropenia, peripheral edema, and liver function test abnormalities were dose-limiting at doses greater than 2.5 mg/m2 per day. Four of six patients developed DLT at 3.0 mg/m2 per day, whereas two of 12 patients treated at 2.5 mg/m2 per day developed DLT. Pharmacokinetic parameters were independent of dose and similar on days 1 and 5. Volume of distribution at steady-state (Vss) was 7.6 +/- 2.0 L/m2, clearance 0.49 +/- 0.18 L/h/m2, and elimination half-life (t1/2) 12.3 +/- 3.8 hours. Peak concentrations (Cmax) on day 1 related to mean percentage decrement in neutrophils (sigmoid maximum effect (Emax) model). Patients who experienced dose-limiting neutropenia had significantly higher Cmax values than patients who did not, whereas nonhematologic DLTs were more related to dose. CONCLUSION: The recommended dose for phase II evaluations of LU103793 daily for 5 days every 3 weeks is 2.5 mg/m2 per day. The lack of prohibitive cardiovascular effects and the generally acceptable toxicity profile support the rationale for performing disease-directed evaluations of LU103793 on the schedule evaluated in this study.

Phase I and pharmacokinetic study of paclitaxel in combination with biricodar, a novel agent that reverses multidrug resistance conferred by overexpression of both MDR1 and MRP.

PURPOSE: To evaluate the feasibility of administering biricodar (VX-710; Incel, Vertex Pharmaceuticals Inc, Cambridge, MA), an agent that modulates multidrug resistance (MDR) conferred by overexpression of both the multidrug resistance gene product (MDR1) P-glycoprotein and the MDR-associated protein (MRP) in vitro, in combination with paclitaxel. The study also sought to determine the maximum-tolerated dose (MTD) of paclitaxel that could be administered with biologically relevant concentrations of VX-710 and characterize the toxicologic and pharmacologic profiles of the VX-710/ paclitaxel regimen. PATIENTS AND METHODS: Patients with solid malignancies were initially treated with VX-710 as a 24-hour infusion at doses that ranged from 10 to 120 mg/m2 per hour. After a 2-day washout period, patients were re-treated with VX-710 on an identical dose schedule followed 8 hours later by paclitaxel as a 3-hour infusion at doses that ranged from 20 to 80 mg/m2. The pharmacokinetics of both VX-710 and paclitaxel were studied during treatment with VX-710 alone and VX-710 and paclitaxel. Thereafter, patients received VX-710 and paclitaxel every 3 weeks. RESULTS: VX-710 alone produced minimal toxicity. The toxicologic profile of the VX-710/paclitaxel regimen was similar to that reported with paclitaxel alone; neutropenia that was noncumulative was the principal dose-limiting toxicity (DLT). The MTD levels of VX-710/ paclitaxel were 120 mg/m2 per hour and 60 mg/m2, respectively, in heavily pretreated patients and 120/60 to 80 mg/m2 per hour in less heavily pretreated patients. At these dose levels, VX-710 steady-state plasma concentrations (Css) ranged from 2.68 to 4.89 microg/mL, which exceeded optimal VX-710 concentrations required for MDR reversal in vitro. The pharmacokinetics of VX-710 were dose independent and not influenced by paclitaxel. In contrast, VX-710 reduced paclitaxel clearance. At the two highest dose levels, which consisted of VX-710 120 mg/m2 per hour and paclitaxel 60 and 80 mg/m2, pertinent pharacokinetic determinants of paclitaxel effect were similar to those achieved with paclitaxel as a 3-hour infusion at doses of 135 and 175 mg/m2, respectively. CONCLUSION: VX-710 alone is associated with minimal toxicity. In combination with paclitaxel, biologically relevant VX-710 plasma concentrations are achieved and sustained for 24 hours, which simulates optimal pharmacologic conditions required for MDR reversal in vitro. The acceptable toxicity profile of the VX-710/ paclitaxel combination and the demonstration that optimal pharmacologic conditions for MDR reversal are achievable support a rationale for further trials of VX710/paclitaxel in patients with malignancies that are associated with de novo or acquired resistance to paclitaxel caused by overexpression of MDR1 and/or MRP.