Progressive multiple sclerosis exhibits decreasing glutamate and glutamine over two years.

BACKGROUND: Few biomarkers of progressive multiple sclerosis (MS) are sensitive to change within the two-year time frame of a clinical trial. OBJECTIVE: To identify biomarkers of MS disease progression with magnetic resonance spectroscopy (MRS) in secondary progressive MS (SPMS). METHODS: Forty-seven SPMS subjects were scanned at baseline and annually for two years. Concentrations of N-acetylaspartate, total creatine, total choline, myo-inositol, glutamate, glutamine, and the sum glutamate+glutamine were measured in a single white matter voxel. RESULTS: Glutamate and glutamine were the only metabolites to show an effect with time: with annual declines of (95% confidence interval): glutamate -4.2% (-6.2% to -2.2%, p < 10(-4)), glutamine -7.3% (-11.8% to -2.9%, p = 0.003), and glutamate+glutamine -5.2% (-7.6% to -2.8%, p < 10(-4)). Metabolite rates of change were more apparent than changes in clinical scores or brain atrophy measures. CONCLUSIONS: The high rates of change of both glutamate and glutamine over two years suggest they are promising new biomarkers of MS disease progression.

Beta-interferon exposure and onset of secondary progressive multiple sclerosis.

BACKGROUND AND PURPOSE: Beta-interferons (IFNß) are the most widely prescribed drugs for patients with multiple sclerosis (MS). However, whether or not treatment with IFNß can delay secondary progressive MS (SPMS) onset remains unknown. Our aim was to examine the association between IFNß exposure and SPMS onset in patients with relapsing-remitting MS (RRMS). METHODS: A retrospective cohort study using British Columbia (Canada) population-based clinical and health administrative data (1985-2008) was conducted. RRMS patients treated with IFNß (n = 794) were compared with untreated contemporary (n = 933) and historical (n = 837) controls. Cohort entry was the first clinic visit during which patients became eligible for IFNß treatment (baseline). The outcome was time from baseline to SPMS onset. Cox regression models with IFNß as a time-dependent exposure were adjusted for sex, and baseline age, disease duration, disability, *socioeconomic status and *comorbidities (*available for the contemporary cohorts only). Additional analyses included propensity score adjustment. RESULTS: The median follow-up for the IFNß-treated, untreated contemporary and historical controls were 5.7, 3.7 and 7.3 years, and the proportions of patients reaching SPMS were 9.2%, 11.8% and 32.9%, respectively. After adjustment for confounders, IFNß exposure was not associated with the risk of reaching SPMS when either the contemporary or the historical untreated cohorts were considered (hazard ratio 1.07; 95% confidence interval 0.93-1.48, and hazard ratio 1.04; 95% confidence interval 0.74-1.46, respectively). Further adjustments and the propensity score yielded results consistent with the main analysis. CONCLUSIONS: Amongst patients with RRMS, use of IFNß was not associated with a delayed onset of SPMS.

Investigation of heterogeneity in the association between interferon beta and disability progression in multiple sclerosis: an observational study.

BACKGROUND AND PURPOSE: It was recently reported that there was no significant overall association between interferon beta exposure and disability progression in relapsing-remitting multiple sclerosis (RRMS) patients in an observational study from Canada. In the current study, the potential for heterogeneity in the association between exposure to interferon beta and disability progression across patients' baseline characteristics was investigated. METHODS: RRMS patients treated with interferon beta (n = 868) and two cohorts of untreated patients (829 contemporary and 959 historical controls) were included. The main outcome was time from interferon beta treatment eligibility (baseline) to a confirmed and sustained Expanded Disability Status Scale (EDSS) score 6 using a multivariable Cox model, with treatment as a time-varying predictor, testing interaction effects for five pre-specified baseline characteristics: sex, age, disease duration, EDSS and annualized relapse rate (ARR) based on the previous 2 years. RESULTS: Significant heterogeneity was found in the association of interferon beta exposure and disability progression only across ARR, and only when treated patients were compared with historical controls (P = 0.005 at a Bonferroni-adjusted alpha of 0.01). For patients with ARR>1, treatment-exposed time was associated with a hazard ratio of 0.38 (95%CI 0.20-0.75) for disability progression compared with the unexposed time. CONCLUSIONS: RRMS patients with more frequent relapses at baseline may be more likely to benefit from interferon beta treatment with respect to long-term disability progression.

'Clinically definite benign multiple sclerosis', an unwarranted conceptual hodgepodge: evidence from a 30-year observational study.

BACKGROUND: Benign multiple sclerosis (BMS) is a controversial concept which is still debated. However identification of this kind of patients is crucial to prevent them from unnecessary exposure to aggressive and/or long term medical treatments. OBJECTIVES: To assess two definitions of 'clinically definite benign multiple sclerosis' (CDBMS) using long-term follow-up data, and to look for prognostic factors of CDBMS. METHODS: In 874 patients with definite relapsing-remitting MS, followed up for at least 10 years, disability was assessed using the Disability Status Scale (DSS). CDBMS was defined by either DSS score≤2 (CDBMS1 group) or DSS score≤ 3 (CDBMS2 group) at 10 years. We estimated the proportion of patients who were still benign at 20 and 30 years after clinical onset. RESULTS: CDBMS frequency estimates were 57.7% and 73.9% when using CDBMS1 and CDBMS2 definitions, respectively. In the CDBMS1 group, only 41.7% (105/252) of cases were still benign 10 years later, and 41.1% (23/56) after an additional decade, while there were 53.8% (162/301) and 59.5% (44/74) respectively in the CDBMS2 group. CONCLUSIONS: This 30-year observational study, which is one of the largest published series, indicates that favourable 10-year disability scores of DSS 2 or 3 fail to ensure a long-term benign course of multiple sclerosis. After every decade almost half of the CDBMS were no longer benign. CDBMS, as currently defined, is an unwarranted conceptual hodgepodge. Other criteria using new biomarkers (genetic, biologic or MRI) should be found to detect benign cases of MS.

Survival in MS: a randomized cohort study 21 years after the start of the pivotal IFNß-1b trial.

OBJECTIVE: To examine the effects of interferon beta (IFNß)-1b on all-cause mortality over 21 years in the cohort of 372 patients who participated in the pivotal randomized clinical trial (RCT), retaining (in the analysis) the original randomized treatment-assignments. METHODS: For this randomized long-term cohort study, the primary outcome, defined before data collection, was the comparison of all-cause mortality between the IFNß-1b 250 µg and placebo groups from the time of randomization through the entire 21-year follow-up interval (intention-to-treat, log-rank test for Kaplan-Meier survival curves). All other survival outcomes were secondary. RESULTS: After a median of 21.1 years from RCT enrollment, 98.4%(366 of 372) of patients were identified, and, of these, 81 deaths were recorded (22.1% [81 of 366]). Patients originally randomly assigned to IFNß-1b 250 µg showed a significant reduction in all-cause mortality over the 21-year period compared with placebo (p = 0.0173), with a hazard ratio of 0.532 (95% confidence interval 0.314-0.902). The hazard rate of death at long-term follow-up by Kaplan-Meier estimates was reduced by 46.8% among IFNß-1b 250 µg-treated patients (46.0% among IFNß-1b 50 µg-treated patients) compared with placebo. Baseline variables did not influence the observed treatment effect. CONCLUSIONS: There was a significant survival advantage in this cohort of patients receiving early IFNß-1b treatment at either dose compared with placebo. Near-complete ascertainment, together with confirmatory findings from both active treatment groups, strengthens the evidence for an IFNß-1b benefit on all-cause mortality. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that early treatment with IFNß-1b is associated with prolonged survival in initially treatment-naive patients with relapsing-remitting multiple sclerosis.

Relative mortality and survival in multiple sclerosis: findings from British Columbia, Canada.

OBJECTIVE: To examine mortality and factors associated with survival in a population based multiple sclerosis (MS) cohort. METHODS: Clinical and demographic data of MS patients registered with the British Columbia MS clinics (1980-2004) were linked to provincial death data, and patients were followed until death, emigration or study end (31 December 2007). Absolute survival and the influence of patient characteristics (sex, disease course (primary progressive (PPMS) vs relapsing onset (R-MS)) and onset age) were estimated by Kaplan-Meier analyses (from birth and disease onset). Mortality relative to the general population was examined using standardised mortality ratios. Excess mortality associated with patient characteristics and time period of cohort entry was assessed by relative survival modelling. RESULTS: Of 6917 patients, 1025 died. Median survival age was 78.6 years (95% CI 77.5 to 79.7) for women and 74.3 years (95% CI 73.1 to 75.4) for men. Survival from onset was longer for R-MS (49.7 years; 95% CI 47.9 to 51.5) than for PPMS (32.5 years; 95% CI 29.5 to 35.7); however, survival age was similar. The overall standardised mortality ratios was 2.89 (95% CI 2.71 to 3.07), and patients survived approximately 6 years less than expected, relative to the general population. PPMS had a higher relative mortality risk compared with R-MS (relative mortality ratio (RMR) 1.52; 95% CI 1.30 to 1.80). Women with PPMS had a relative survival disadvantage compared with men with PPMS (RMR 1.55; 95% CI 1.19 to 2.01). Relative survival within 10 years of cohort entry was similar between time periods. CONCLUSIONS: Some of the longest MS survival times are reported here but the risk of death was still greater than in the age, sex and calendar year matched general population. No evidence of increased survival over time was found when improved survival in the general population was taken into consideration.

A phase III study evaluating the efficacy and safety of MBP8298 in secondary progressive MS.

OBJECTIVE: To evaluate the efficacy and safety of MBP8298 in subjects with secondary progressive multiple sclerosis (SPMS) who express human leukocyte antigen (HLA) haplotype DR2 or DR4 (DR2(+) or DR4(+)). METHODS: This multicenter randomized 2-year, double-blind, placebo-controlled study included 612 subjects with a diagnosis of SPMS and an Expanded Disability Status Scale (EDSS) score of 3.5-6.5, stratified according to baseline EDSS score (3.5-5.0, or 5.5-6.5) and HLA haplotype (DR2(+) or DR4(+), or DR2(-)/DR4(-)). Upon entry of 100 DR2(-)/DR4(-) subjects, further study enrollment was limited to DR2(+) or DR4(+) subjects. Subjects were randomly assigned to either 500 mg MBP8298 or placebo, given by IV injection once every 6 months for 2 years. The primary outcome measure was time to progression by ≥1.0 EDSS point (or 0.5 point if baseline EDSS was 5.5 or higher), confirmed 6 months later. Secondary outcomes included mean change in EDSS, mean change in Multiple Sclerosis Functional Composite, MRI changes, annualized relapse rate, and quality of life. RESULTS: There were no significant differences between treatment groups in either the primary or secondary endpoints. MBP8298 was well tolerated in all treated subjects with no safety issues identified. CONCLUSION: In the population studied, treatment with MBP8298 did not provide a clinical benefit compared to placebo. CLASSIFICATION OF EVIDENCE: This study provides Class 1 evidence that MBP8298 is not effective in patients with SPMS who are HLA DR2(+) or DR4(+).

High-dose frequency beta-interferons increase the risk of liver test abnormalities in multiple sclerosis: a longitudinal study.

BACKGROUND: Post-marketing studies and case reports have linked beta-interferon (IFNß) treatment with liver enzyme abnormalities and liver injuries in patients with multiple sclerosis (MS). Few predictors of risk exist. OBJECTIVE: We investigated the effect of IFNß and other patient characteristics on levels of the liver enzyme, alanine aminotransferase (ALT). METHOD: Repeated ALT test results were reviewed retrospectively for 1064 MS patients prescribed an IFNß as their first immunomodulatory drug. Liver enzyme abnormality was defined as an ALT elevation twice the upper limit of normal (≥ 2 ULN). The Generalized Estimating Equation (GEE) was used to analyze the effect of age (≤ 35, >35-40, >40-45, >45 years), gender, disease duration, IFNß product, and duration of treatment (≤ 5, >5-15, >15-40, >40 months) on de novo liver enzyme abnormality. RESULTS: Over a mean treatment period of 38.7 months (SD=34.9), 12.4% (95/766) of MS patients developed de novo liver enzyme abnormality. Multivariable GEE results showed a dose frequency response effect of IFNßs on liver enzyme abnormality: OR=3.8(95% CI: 1.6-9.2) for IFNß-1a 44 µg SC, and OR=3.4 (95% CI: 1.5-7.9) for IFNß-1b 250 µg SC compared with the lower frequency IFNß-1a 30 µg IM. Younger age (≤ 40 years), male gender, and ≤ 15 months of IFNß exposure were also independent predictors. CONCLUSION: A dose frequency response effect was observed, with high-frequency IFNßs having the greatest risk. The first 15 months of treatment, men, and younger patients were also associated with elevated risk. Regular ALT monitoring in MS patients appears prudent; long-term consequences of ALT elevations should be further investigated.

Two-year study of cervical cord volume and myelin water in primary progressive multiple sclerosis.

BACKGROUND: Spinal cord involvement in multiple sclerosis (MS) is common and an important element in disability. Previous studies demonstrated smaller cervical cord area at the C2 level in MS compared to controls, and a decrease in cord area over 12 months, most marked in primary progressive MS (PPMS). A subset of subjects participating in a multicentre, double-blind, placebo-controlled clinical trial evaluating the efficacy of glatiramer acetate in PPMS (PROMiSe trial) were followed for 2 years. METHODS: 24 PPMS subjects, randomized to placebo (n = 9) and glatiramer acetate (n = 15), and 24 matched controls were studied. Cervical cord volume (CCV) at C2-3 was determined using a 3D inversion recovery (IR)-prepared spoiled-gradient echo sequence. Myelin water fraction (MWF) at C2-3 was obtained using a 32-echo IR-prepared relaxation sequence. Scans were repeated at baseline, years 1 and 2. RESULTS: Baseline CCV was significantly smaller for PPMS than controls [median (interquartile range) 951 (829-1043) vs. 1072 (1040-1129) mm(3), p = 0.0004] and MWF trended to be lower in PPMS cord [median (interquartile range) 0.225 (0.187-0.267) vs. 0.253 (0.235-0.266), p = 0.12]. Baseline CCV correlated with baseline Expanded Disability Status Scale, disease duration, brain white and grey matter volume. In PPMS, CCV was significantly decreased at year 1 (-0.83%, p = 0.04) and year 2 (-1.65%, p = 0.02). Baseline MWF correlated with baseline CCV and brain white and grey matter volume. MWF was significantly decreased from baseline for PPMS at year 2 (-10.5%, p = 0.01). Treatment effect was not detected on change in CCV nor MWF. CONCLUSIONS: Metrics at the level of the cord, including volume and MWF at C2-3, were lower in PPMS than controls and changed over 2 years only in PPMS.

Serial combination therapy: is immune modulation in multiple sclerosis enhanced by initial immune suppression?

BACKGROUND: Although the concept that an initial course of immune-suppression facilitates subsequent immune-modulation (such as Th1 to Th2 deviation) is attractive for several autoimmune diseases, such a mechanism for serial-combination therapy has never been formally demonstrated. Recently, brief mitoxantrone induction-chemotherapy followed by immune-modulation with glatiramer acetate (GA) was significantly more effective at reducing multiple sclerosis disease activity than with GA alone. OBJECTIVE: To examine whether the benefit of initial immune suppression with mitoxantrone before GA treatment is associated with more efficient immune modulation. METHODS: IgG1/IgG4 GA-reactive antibody profiles, previously established as markers of GA-induced Th2 immune-deviation, were prospectively measured in vivo in patients treated with GA alone or with mitoxantrone induction therapy followed by GA. RESULTS: Significant and sustained increase in IgG4 antibodies (and the anticipated reversal of the IgG1/IgG4 ratio) was seen in patients treated with GA alone. Combination therapy resulted in lesser IgG4 induction (and no reversal of IgG1/IgG4 ratio). Thus, the enhanced efficacy of mitoxantrone-GA combination regimen was associated with decreased, rather than increased, efficiency of shifting the GA-reactive IgG1/IgG4 antibody profile. CONCLUSION: These results provide important insights into mechanisms of combination therapy and therapeutic strategies for autoimmune diseases.

Longitudinal changes in myelin water fraction in two MS patients with active disease.

Multiple sclerosis (MS) is characterised by focal areas that undergo cycles of demyelination and remyelination. Although conventional magnetic resonance imaging is very effective in localising areas of damage, these techniques are not pathology specific. A newer technique, T(2) relaxation, can separate water from brain into three compartments: (1) a long T(2) component (>2 s) arising from CSF, (2) an intermediate T(2) component (~80 ms) attributed to intra- and extra-cellular water and (3) a short T(2) component (~20 ms) assigned to water trapped in between the myelin bilayers (termed myelin water). Histological evidence shows that myelin water is a specific marker of myelination. The goal of this work was to follow changes in total water content (WC) and myelin water fraction (MWF) in evolving MS lesions over one year. Multi-echo T(2) relaxation data was collected and used to measure water content and myelin water fraction from three new MS lesions in two patients. WC increased in the three large (>1 cm(3)) lesions at lesion appearance and remained elevated in the central core. Two lesions showed low MWF in the core suggesting demyelination upon first appearance. At later time points, one lesion showed a decrease in volume of low MWF, reflecting remyelination whereas the volume of low MWF in the other lesion core remained constant. This work provides evidence that MWF and WC can monitor demyelination and remyelination in MS.

Ten years of adverse drug reaction reports for the multiple sclerosis immunomodulatory therapies: a Canadian perspective.

Adverse drug reaction (ADR) reporting is essential in the post-marketing surveillance of drugs, detection of serious adverse reactions, and has been the basis for drug withdrawals. The study aimed to examine ADR reporting patterns to the multiple sclerosis (MS) immunomodulatory drugs (IMD) in Canada. All ADRs reported to the Canadian ADR Monitoring Program (CADRMP) from 1965 to March 2006 (n=193 208) were accessed and ADRs in which an IMD for MS (beta-interferon or glatiramer acetate) was the suspected drug extracted (n=888 reports were dated March/96-March/06). Almost half of all IMD ADRs reports (438/888) were sourced through the patient compared to 14.9% (10 649/71 373) of all ADRs reported to CADRMP over the same period. Of IMD ADR reports, 88.7% (788/888) were directed through the manufacturer compared to 57.7% (41197/71373) of all ADRs. Encouragement to others involved in patient care, such as pharmacists, nurses and physicians might enhance reporting of MS ADRs. Despite the limitations of ADR reporting data, previously unpublished case reports in several understudied MS populations were detailed: paediatrics (or= 65 years, n=23) and during pregnancy (n=12). In addition, 46 deaths suspected by the reporter as being related to IMD treatment were detailed as well as three possible drug interactions.

Reduced effectiveness of long-term interferon-beta treatment on relapses in neutralizing antibody-positive multiple sclerosis patients: a Canadian multiple sclerosis clinic-based study.

Multiple sclerosis (MS) patients treated with interferon-beta (IFN-beta) often form anti-IFN-beta antibodies accompanied by a reduction in IFN-beta bioavailability. The clinical effect of these antibodies remains controversial. MS patients in British Columbia, Canada, must be diagnosed and evaluated annually by neurologists in an MS clinic in order to be reimbursed for their IFN-beta prescriptions. We have identified at the UBC MS clinic a cohort of 262 patients, each having been treated with a single IFN-beta preparation more than three years, some for nearly a decade. Of 119 patients treated with Betaseron (IFN-beta1b), 18 (15.1%) were neutralizing antibody positive (NAb+) at the time of the study, whereas of 131 treated with subcutaneous Rebif (IFN-beta1a SC), 16 (12.2%) were NAb+, but none of 12 treated with intramuscular Avonex (IFN-beta1a) had detectable neutralizing antibodies. During the first two years of treatment, the relapse rate was significantly reduced from pre-treatment rates (P<0.001) and appeared to be unaffected by the subsequent NAb status. However, the relapse rates in the NAb+ patients were significantly greater than in the NAb- patients during years 3 (P<0.010) and 4 (P<0.027). Betaseron-treated NAb+ patients tended to have more relapses than NAb- patients during year 3 and this almost reached significance (P=0.056) but their relapse rate did not differ in year 4 and later. In contrast, Rebif-treated NAb+ patients tended to have more relapses in year 3 than Rebif-treated NAb- patients (P=0.074), but in year 4 they clearly (P=0.009) had more relapses than Rebif-treated NAb- patients. There was no convincing effect on progression of disability in any group.

Neutralizing antibodies to interferon beta: assessment of their clinical and radiographic impact: an evidence report: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

The clinical and radiologic impact of developing neutralizing antibodies (NAbs) to interferon beta (IFNbeta) while on this therapy for multiple sclerosis (MS) is assessed. On the basis of Class II and III evidence, it is concluded that treatment of patients with MS with IFNbeta (Avonex, Betaseron, or Rebif) is associated with the production of NAbs (Level A). NAbs in the serum are probably associated with a reduction in the radiographic and clinical effectiveness of IFNbeta treatment (Level B). In addition, the rate of NAb production is probably less with IFNbeta-1a treatment than with IFNbeta-1b treatment, although the magnitude and persistence of this difference is difficult to determine (Level B). Finally, it is probable that there is a difference in seroprevalence due to variability in the dose of IFNbeta injected or in the frequency or route of its administration (Level B). Regardless of the explanation, it seems clear that IFNbeta-1a (as it is currently formulated for IM injection) is less immunogenic than the current IFNbeta preparations (either IFNbeta-1a or IFNbeta-1b) given multiple times per week subcutaneously (Level A). However, because NAbs disappear in some patients even with continued IFNbeta treatment (especially in patients with low titers), the persistence of this difference is difficult to determine (Level B). Although the finding of sustained high-titer NAbs (>100 to 200 NU/mL) is associated with a reduction in the therapeutic effects of IFNbeta on radiographic and clinical measures of MS disease activity, there is insufficient information on the utilization of NAb testing to provide specific recommendations regarding when to test, which test to use, how many tests are necessary, or which cutoff titer to apply (Level U).

Liver test abnormalities in multiple sclerosis: findings from placebo-treated patients.

The risk of an abnormal liver test in 813 patients with multiple sclerosis or clinically isolated syndrome enrolled in placebo arms of clinical trials was greater than expected for alanine aminotransferase (ALT) (relative risk [RR] 3.7; 95% CI: 2.3 to 6.0) and aspartate aminotransferase (AST) (RR 2.2; 95% CI: 1.3 to 3.6), although not alkaline phosphatase (AP) or total bilirubin, at first presentation. Abnormal test results were associated with higher body mass index (ALT only), male gender (ALT only), and a relapsing-remitting (vs secondary-progressive) course (ALT and AST only).

Acetylcholine receptor antibodies in myasthenia gravis are associated with greater risk of diabetes and thyroid disease.

OBJECTIVE: Myasthenia gravis (MG) may be associated with the presence of acetylcholine receptor antibodies (AChRAb) [seropositive MG (SPMG)] or their absence [seronegative MG (SNMG)]. Along with features of MG, the presence of the AChRAb may relate to the existence of other immune-mediated diseases. We sought to determine the association of SPMG with other potential autoimmune diseases. METHODS: A retrospective evaluation of prospectively identified MG patients at a tertiary care center was performed, with patients separated into SPMG and SNMG. Prevalence of other immune-mediated disorders, as well as the epidemiology, sensitivity of diagnostic testing, and thymic pathology, was contrasted between both patient groups. RESULTS: Of the 109 MG patients identified, 66% were SPMG. SPMG was associated with a greater likelihood of significant repetitive stimulation decrement, the presence of either thymoma or thymic hyperplasia, and the presence of thyroid disease. In addition, all patients with a diagnosis of diabetes, concurrent with MG, were found to be SPMG. CONCLUSIONS: AChRAb and SPMG impart not only a distinctive clinical and electrophysiological phenotype of MG, but are also associated with the heightened presence of endocrinological disease.

Paclitaxel-loaded microparticles and implants for the treatment of brain cancer: preparation and physicochemical characterization.

The aim of this study was to prepare different types of paclitaxel-loaded, PLGA-based microparticles and lipidic implants, which can directly be injected into the brain tissue. Releasing the drug in a time-controlled manner over several weeks, these systems are intended to optimize the treatment of brain tumors. The latter is particularly difficult because of the blood-brain barrier (BBB), hindering most drugs to reach the target tissue upon systemic administration. Especially paclitaxel (being effective for the treatment of ovarian, breast, lung and other cancers) is not able to cross the BBB to a notable extent since it is a substrate of the efflux transporter P-glycoprotein. Both, biodegradable microparticles as well as small, cylindrical, glycerol tripalmitate-based implants (which can be injected using standard needles) were prepared with different paclitaxel loadings. The effects of several formulation and processing parameters on the resulting drug release kinetics were investigated in phosphate buffer pH 7.4 as well as in a diethylnicotinamide (DENA)/phosphate buffer mixture. Using DSC, SEM, SEC and optical microscopy deeper insight into the underlying drug release mechanisms could be gained. The presence of DENA in the release medium significantly increased the solubility of paclitaxel, accelerated PLGA degradation, increased the mobility of the polymer and drug molecules and fundamentally altered the geometry of the systems, resulting in increased paclitaxel release rates.

Prospective assessment of changing from placebo to IFN beta-1a in relapsing MS: the PRISMS study.

The efficacy of interferon (IFN) beta has been shown in several placebo-controlled, parallel-group studies in relapsing-remitting multiple sclerosis (RRMS). PRISMS, the largest such study to date, clearly demonstrated the efficacy of IFN beta-1a on all outcome measures over 2 years during the placebo-controlled, parallel-group phase. However, this study's placebo-crossover design also provided us with a unique opportunity to conduct a prospective within-group assessment, eliminating the impact of inter-patient variability. At the start of year 3, patients receiving placebo during years 1-2 were re-randomized in a dose-blinded fashion to receive IFN beta-1a, 22 or 44 mcg subcutaneously three times weekly, during years 3 and 4. Clinic visits occurred 3-6 monthly and T2 MRI scans were obtained after 1 and 2 years on therapy. Comparison of the mean relapse count per patient over 2 years (the primary outcome measure) during time on placebo (years 1 and 2) with that during active treatment (years 3 and 4) revealed a decrease from 2.6 to 1.2 in both dose groups (54% relative reduction; p<0.001). Disability progression, T2 MRI lesion activity and accumulation of T2 lesion burden were also significantly improved with therapy (p<0.01). No new safety issues were noted. These data provide further support for IFN beta-1a's efficacy in RRMS. The ability to detect significant treatment effects with reduced patient numbers in this type of before/after analysis, may be due to the reduction in inter-patient variability.