Diroximel fumarate in patients with relapsing-remitting multiple sclerosis: Final safety and efficacy results from the phase 3 EVOLVE-MS-1 study

BACKGROUND

Diroximel fumarate (DRF) is approved for adults with relapsing-remitting multiple sclerosis (RRMS) in Europe and for relapsing forms of MS in the United States. DRF and dimethyl fumarate (DMF) yield bioequivalent exposure of the active metabolite monomethyl fumarate. Prior studies indicated fewer gastrointestinal (GI)-related adverse events (AEs) with DRF compared with DMF.

OBJECTIVE

To report final outcomes from EVOLVE-MS-1.

METHODS

EVOLVE-MS-1 was an open-label, 96-week, phase 3 study assessing DRF safety, tolerability, and efficacy in patients with RRMS. The primary endpoint was safety and tolerability; efficacy endpoints were exploratory.

RESULTS

Overall, 75.7% (800/1057) of patients completed the study; median exposure was 1.8 (range: 0.0-2.0) years. AEs occurred in 938 (88.7%) patients, mostly of mild (28.9%) or moderate (50.3%) severity. DRF was discontinued due to AEs in 85 (8.0%) patients, with < 2% discontinuing due to GI or flushing/flushing-related AEs. At Week 96, mean number of gadolinium-enhancing lesions was significantly reduced from baseline (72.7%; p < 0.0001); adjusted annualized relapse rate was 0.13 (95% confidence interval: 0.11-0.15).

CONCLUSION

DRF was generally well tolerated over 2 years, with few discontinuations due to AEs; radiological measures indicated decreased disease activity from baseline. These outcomes support DRF as a treatment option in patients with RRMS.

Matching-Adjusted Indirect Comparisons of Diroximel Fumarate, Ponesimod, and Teriflunomide for Relapsing Multiple Sclerosis

INTRODUCTION

Diroximel fumarate (DRF), ponesimod (PON), and teriflunomide (TERI) are oral disease-modifying therapies approved for the treatment of relapsing multiple sclerosis. No randomized trials have compared DRF versus PON or TERI.

OBJECTIVES

The objectives of this analysis were to compare DRF versus PON and DRF versus TERI for clinical and radiological outcomes.

METHODS

We used individual patient data from EVOLVE-MS-1, a 2-year, open-label, single-arm, phase III trial of DRF (n = 1057), and aggregated data from OPTIMUM, a 2-year, double-blind, phase III trial comparing PON (n = 567) and TERI (n = 566). To account for cross-trial differences, EVOLVE-MS-1 data were weighted to match OPTIMUM's average baseline characteristics using an unanchored matching-adjusted indirect comparison. We examined the outcomes of annualized relapse rate (ARR), 12-week confirmed disability progression (CDP), 24-week CDP, absence of gadolinium-enhancing (Gd+) T1 lesions, and absence of new/newly enlarging T2 lesions.

RESULTS

After weighting, we did not observe strong evidence of differences between DRF and PON for ARR [DRF versus PON incidence rate difference (IRD) -0.02; 95% confidence interval (CI) -0.08, 0.04; incidence rate ratio (IRR) 0.92; 95% CI 0.61, 1.2], 12-week CDP [risk difference (RD) -2.5%; 95% CI -6.3, 1.2; risk ratio (RR) 0.76; 95% CI 0.38, 1.1], 24-week CDP (RD -2.7%; 95% CI -6.0, 0.63; RR 0.68; 95% CI 0.28, 1.0), and absence of new/newly enlarging T2 lesions (RD -2.5%; 95% CI -13, 7.4; RR 0.94; 95% CI 0.70, 1.2). However, a higher proportion of DRF-treated patients were free of Gd+ T1 lesions than PON-treated patients (RD 11%; 95% CI 6.0, 16; RR 1.1; 95% CI 1.06, 1.2). Compared with TERI, DRF showed improved ARR (IRD -0.08; 95% CI -0.15, -0.01; IRR 0.74; 95% CI 0.50, 0.94), 12-week CDP (RD -4.2%; 95% CI -7.9, -0.48; RR 0.67; 95% CI 0.38, 0.90), 24-week CDP (RD -4.3%; 95% CI -7.7, -1.1; RR 0.57; 95% CI 0.26, 0.81), and absence of Gd+ T1 lesions (RD 25%; 95% CI 19, 30; RR 1.4; 95% CI 1.3, 1.5). However, DRF and TERI did not appear to differ significantly with respect to absence of new/newly enlarging T2 lesions when based on comparisons using the overall EVOLVE-MS-1 sample (RD 8.5%; 95% CI -0.93, 18; RR 1.3; 95% CI 0.94, 1.6), or in a sensitivity analysis restricted to newly enrolled EVOLVE-MS-1 patients (RD 2.7%; 95% CI -9.1, 14; RR 1.1; 95% CI 0.68, 1.5).

CONCLUSIONS

We did not observe differences between DRF and PON for ARR, CDP, and absence of new/newly enlarging T2 lesions, but there was a higher proportion of patients free of Gd+ T1 lesions among DRF-treated patients than PON-treated patients. DRF had improved efficacy versus TERI for all clinical and radiological outcomes, except for absence of new/newly enlarging T2 lesions.

CLINICAL TRIALS REGISTRATION

EVOLVE-MS-1 (ClinicalTrials.gov identifier: NCT02634307); OPTIMUM (ClinicalTrials.gov identifier: NCT02425644).

Satisfaction with alemtuzumab in relapsing multiple sclerosis patients: Results from the real-world PRO-ACT study

BACKGROUND

Patient-reported outcomes are increasingly used in the management of patients with multiple sclerosis to understand the patient's perspective of disease and treatment. These measures provide insights into important factors including treatment satisfaction, physical and psychological function, and quality of life.

OBJECTIVE

To present results from the real-world PRO-ACT study in patients with multiple sclerosis who switched to alemtuzumab from another disease-modifying therapy.

METHODS

This 24-month, prospective, multicenter, observational study had a primary endpoint of change in overall satisfaction, measured using the Treatment Satisfaction Questionnaire for Medication (TSQM) version 1.4. Secondary endpoints included the Multiple Sclerosis Impact Scale-29 (MSIS-29), Modified Fatigue Impact Scale-5 (MFIS-5), and the Patient-Determined Disease Steps (PDDS). Safety was monitored with adverse events (AEs).

RESULTS

Of 199 enrolled patients, improvements were observed in mean TSQM scores for overall satisfaction (baseline, 50.3; year 2, + 13.2; p < 0.0001), effectiveness (49.3 and + 12.2; p < 0.0001), and side effects (77.6 and + 4.5; p = 0.04). Improvements were also observed in MSIS-29 physical (52.4 and -6.0; p < 0.0001), MSIS-29 psychological (53.4 and -7.0; p = 0.0003), and MFIS-5 (12.8 and -1.7; p < 0.0001). Most (95.0%) patients experienced ≥ 1 AE (88.4% mild, 67.8% moderate).

CONCLUSIONS

The primary endpoint was met; the safety of alemtuzumab was consistent with pivotal studies.

Ublituximab versus Teriflunomide in Relapsing Multiple Sclerosis

BACKGROUND

The monoclonal antibody ublituximab enhances antibody-dependent cellular cytolysis and produces B-cell depletion. Ublituximab is being evaluated for the treatment of relapsing multiple sclerosis.

METHODS

In two identical, phase 3, double-blind, double-dummy trials (ULTIMATE I and II), participants with relapsing multiple sclerosis were randomly assigned in a 1:1 ratio to receive intravenous ublituximab (150 mg on day 1, followed by 450 mg on day 15 and at weeks 24, 48, and 72) and oral placebo or oral teriflunomide (14 mg once daily) and intravenous placebo. The primary end point was the annualized relapse rate. Secondary end points included the number of gadolinium-enhancing lesions on magnetic resonance imaging (MRI) by 96 weeks and worsening of disability.

RESULTS

A total of 549 participants were enrolled in the ULTIMATE I trial, and 545 were enrolled in the ULTIMATE II trial; the median follow-up was 95 weeks. In the ULTIMATE I trial, the annualized relapse rate was 0.08 with ublituximab and 0.19 with teriflunomide (rate ratio, 0.41; 95% confidence interval [CI], 0.27 to 0.62; P<0.001); in the ULTIMATE II trial, the annualized relapse rate was 0.09 and 0.18, respectively (rate ratio, 0.51; 95% CI, 0.33 to 0.78; P = 0.002). The mean number of gadolinium-enhancing lesions was 0.02 in the ublituximab group and 0.49 in the teriflunomide group (rate ratio, 0.03; 95% CI, 0.02 to 0.06; P<0.001) in the ULTIMATE I trial and 0.01 and 0.25, respectively (rate ratio, 0.04; 95% CI, 0.02 to 0.06; P<0.001), in the ULTIMATE II trial. In the pooled analysis of the two trials, 5.2% of the participants in the ublituximab group and 5.9% in the teriflunomide group had worsening of disability at 12 weeks (hazard ratio, 0.84; 95% CI, 0.50 to 1.41; P = 0.51). Infusion-related reactions occurred in 47.7% of the participants in the ublituximab group. Serious infections occurred in 5.0% in the ublituximab group and in 2.9% in the teriflunomide group.

CONCLUSIONS

Among participants with relapsing multiple sclerosis, ublituximab resulted in lower annualized relapse rates and fewer brain lesions on MRI than teriflunomide over a period of 96 weeks but did not result in a significantly lower risk of worsening of disability. Ublituximab was associated with infusion-related reactions. (Funded by TG Therapeutics; ULTIMATE I and II ClinicalTrials.gov numbers, NCT03277261 and NCT03277248.).

Comparison of switching to 6-week dosing of natalizumab versus continuing with 4-week dosing in patients with relapsing-remitting multiple sclerosis (NOVA): a randomised, controlled, open-label, phase 3b trial

BACKGROUND

Treatment with natalizumab once every 4 weeks is approved for patients with relapsing-remitting multiple sclerosis, but is associated with a risk of progressive multifocal leukoencephalopathy. Switching to extended-interval dosing is associated with lower progressive multifocal leukoencephalopathy risk, but the efficacy of this approach is unclear. We aimed to assess the safety and efficacy of natalizumab once every 6 weeks compared with once every 4 weeks in patients with relapsing-remitting multiple sclerosis.

METHODS

We did a randomised, controlled, open-label, phase 3b trial (NOVA) at 89 multiple sclerosis centres across 11 countries in the Americas, Europe, and Western Pacific. Included participants were aged 18-60 years with relapsing-remitting multiple sclerosis and had been treated with intravenous natalizumab 300 mg once every 4 weeks with no relapses for at least 12 months before randomisation, with no missed doses in the previous 3 months. Participants were randomly assigned (1:1), using a randomisation sequence generated by the study funder and contract personnel with interactive response technology, to switch to natalizumab once every 6 weeks or continue with once every 4 weeks. The centralised MRI reader, independent neurology evaluation committee, site examining neurologists, site backup examining neurologists, and site examining technicians were masked to study group assignments. The primary endpoint was the number of new or newly enlarging T2 hyperintense lesions at week 72, assessed in all participants who received at least one dose of assigned treatment and had at least one postbaseline MRI, relapse, or neurological examination or efficacy assessment. Missing primary endpoint data were handled under prespecified primary and secondary estimands: the primary estimand included all data, regardless of whether participants remained on the assigned treatment; the secondary estimand classed all data obtained after treatment discontinuation or study withdrawal as missing. Safety was assessed in all participants who received at least one dose of study treatment. Study enrolment is closed and an open-label extension study is ongoing. This study is registered with EudraCT, 2018-002145-11, and ClinicalTrials.gov, NCT03689972.

FINDINGS

Between Dec 26, 2018, and Aug 30, 2019, 605 patients were assessed for eligibility and 499 were enrolled and assigned to receive natalizumab once every 6 weeks (n=251) or once every 4 weeks (n=248). After prespecified adjustments for missing data, mean numbers of new or newly enlarging T2 hyperintense lesions at week 72 were 0·20 (95% CI 0·07-0·63) in the once every 6 weeks group and 0·05 (0·01-0·22) in the once every 4 weeks group (mean lesion ratio 4·24 [95% CI 0·86-20·85]; p=0·076) under the primary estimand, and 0·31 (95% CI 0·12-0·82) and 0·06 (0·01-0·31; mean lesion ratio 4·93 [95% CI 1·05-23·20]; p=0·044) under the secondary estimand. Two participants in the once every 6 weeks group with extreme new or newly enlarging T2 hyperintense lesion numbers (≥25) contributed most of the excess lesions. Adverse events occurred in 194 (78%) of 250 participants in the once every 6 weeks group and 190 (77%) of 247 in the once every 4 weeks group, and serious adverse events occurred in 17 (7%) and 17 (7%), respectively. No deaths were reported. There was one case of asymptomatic progressive multifocal leukoencephalopathy (without clinical signs) in the once every 6 weeks group, and no cases in the once every 4 weeks group; 6 months after diagnosis, the participant was without increased disability and remained classified as asymptomatic.

INTERPRETATION

We found a numerical difference in the mean number of new or newly enlarging T2 hyperintense lesions at week 72 between the once every 6 weeks and once every 4 weeks groups, which reached significance under the secondary estimand, but interpretation of statistical differences (or absence thereof) is limited because disease activity in the once every 4 weeks group was lower than expected. The safety profiles of natalizumab once every 6 weeks and once every 4 weeks were similar. Although this trial was not powered to assess differences in risk of progressive multifocal leukoencephalopathy, the occurrence of the (asymptomatic) case underscores the importance of monitoring and risk factor consideration in all patients receiving natalizumab.

FUNDING

Biogen.

038 Pregnancy outcomes in patients treated with ocrelizumab

Background

Ocrelizumab is approved for the treatment of relapsing forms and primary progressive multiple sclerosis (MS).

Methods

We report analyses of pregnancies in women who received ocrelizumab in clinical trials/post- marketing sources up to 31/03/2019. Contraceptive requirements for women of childbearing potential were per label (during treatment and for 6/12 months after the last infusion) or adapted in clinical trials (two methods for 6 months or until 48 weeks after the last infusion/until B-cell repletion [whichever longer]). Foetal exposure was defined as the last infusion occurring within 3 months of conception or during pregnancy if the conception date was unknown.

Results

A total of 362 ocrelizumab-exposed pregnancies in women with either MS (N=267), rheumatoid arthritis/systemic lupus erythematosus (N=33) or an unknown indication (N=62) have been reported. Of the 267 pregnancies in women with MS, 118 were considered to have foetal exposure, 47 did not have foetal exposure and 102 had unknown foetal exposure. Preliminary pregnancy outcomes in MS patients include: 62 live births, 86 ongoing pregnancies, 25 elective abortions, 10 spontaneous abortions, 1 stillbirth, 3 ectopic pregnancies, 22 lost to follow-up and 58 unknown/unreported outcomes.

Conclusions

Cases to date do not suggest an increased risk of adverse pregnancy/foetal outcomes with ocrelizumab.

p.brex@nhs.net

Safety and clinical effectiveness of peginterferon beta-1a for relapsing multiple sclerosis in the real-world setting: Interim results from the Plegridy Observational Program

BACKGROUND

The Plegridy Observational Program (POP) is an ongoing, 5-year, phase 4 real-world study of the safety and effectiveness of subcutaneous peginterferon beta-1a in patients with relapsing multiple sclerosis (RMS).

METHODS

This interim analysis from POP assessed the safety and effectiveness of peginterferon beta-1a, including subgroup analyses of patients aged < 50 and ≥ 50 years, newly diagnosed and non-newly diagnosed patients, and new and experienced peginterferon beta-1a users.

RESULTS

A total of 1208 patients enrolled in POP. Mean (standard deviation) peginterferon treatment duration in the overall population was 757.0 (529.5) days. The overall incidence of treatment-emergent adverse events (AEs) was 65.5%, and the incidence was higher in new than experienced peginterferon beta-1a users (78.1 vs 52.4%). The overall incidence of treatment-emergent serious AEs was 7.6%, and the incidence was lower in younger than older patients (5.8 vs 11.1%). No new or unexpected safety signals were reported. Overall treatment discontinuation due to AEs occurred in 20.7% of patients, with a higher proportion of new than experienced peginterferon beta-1a users (27.0 vs 14.2%) discontinuing treatment due to AEs. Flu-like symptoms and injection site reactions were significant predictors of time to treatment discontinuation. The adjusted annualized relapse rate (ARR) was 0.12 (95% confidence interval 0.11-0.13) in the overall population and was similar across all subgroups. In the overall population at 4 years, 79.1% of patients were relapse free, the estimated cumulative proportion of patients with confirmed disability worsening was 1.8%, and > 67% of patients achieved clinical no evidence of disease activity (NEDA).

CONCLUSIONS

Safety data of patients enrolled in POP are consistent with the established clinical safety profile of peginterferon beta-1a. In addition, the low ARR and high proportion of patients achieving clinical NEDA at 4 years across all subgroups indicates the effectiveness of peginterferon beta-1a in treating RMS in real-world clinical settings.

Improved gastrointestinal profile with diroximel fumarate is associated with a positive impact on quality of life compared with dimethyl fumarate: results from the randomized, double-blind, phase III EVOLVE-MS-2 study

Background:

Diroximel fumarate (DRF) is a novel oral fumarate approved for relapsing forms of multiple sclerosis (MS). DRF demonstrated significantly improved gastrointestinal (GI) tolerability versus dimethyl fumarate (DMF) with fewer days of Individual Gastrointestinal Symptom and Impact Scale (IGISIS) scores ⩾2, GI adverse events (AEs), and treatment discontinuations due to GI AEs. Our aim was to evaluate the impact of GI tolerability events on quality of life (QoL) for patients with relapsing–remitting MS who received DRF or DMF in EVOLVE-MS-2.

Methods:

A post hoc analysis was conducted in patients who were enrolled in the randomized, blinded, 5-week, EVOLVE-MS-2 [ClinicalTrials.gov identifier: NCT03093324] study of DRF versus DMF. Patients completed daily IGISIS and Global GISIS (GGISIS) eDiary questionnaires to assess GI symptom intensity and interference with daily activities and work.

Results:

In total, 504 patients (DRF, n = 253; DMF, n = 251) received study drug and 502 (DRF, n = 253; DMF, n = 249) completed at least one post-baseline questionnaire. With DRF, GI symptoms were less likely to interfere ‘quite a bit’ or ‘extremely’ with regular daily activities [IGISIS: DRF, 9.5% (24/253) versus DMF, 28.9% (72/249)] or work productivity [GGISIS: DRF, 6.1% (10/165) versus DMF, 11.3% (18/159)]. DRF-treated patients had fewer days with ⩾1 h of missed work (DRF, 43 days, n = 20 versus DMF, 88 days, n = 26). DMF-treated patients reported highest GI symptom severity and missed work at week 2–3 shortly after completing the titration period, which coincided with the majority of GI-related treatment discontinuations [58.3% (7/12)]. GI tolerability AEs [DRF, 34.8% (88/253); DMF, 48.2% (121/251)], concomitant symptomatic medication use [DRF, 19.3% (17/88) versus DMF, 30.6% (37/121)], and GI-related discontinuations (DRF, 0.8% versus DMF, 4.8%) were lower with DRF versus DMF.

Conclusions:

The improved GI tolerability with DRF translated into clinically meaningful benefits to QoL, as patients experienced less impact on daily life and work and required less concomitant symptomatic medication use.

Trial registration:

[ClinicalTrials.gov identifier: NCT03093324]

A phase 2 multicenter study of ublituximab, a novel glycoengineered anti-CD20 monoclonal antibody, in patients with relapsing forms of multiple sclerosis

Background:

Ublituximab, a novel monoclonal antibody (mAb) targeting a unique epitope on the CD20 antigen, is glycoengineered for enhanced B-cell targeting through antibody-dependent cellular cytotoxicity (ADCC). Greater ADCC may allow lower doses and shorter infusion times versus other anti-CD20 mAbs.

Objective:

The objective was to determine optimal dose, infusion time, and activity of ublituximab in relapsing multiple sclerosis.

Methods:

This is a phase 2, placebo-controlled study. Patients received three ublituximab infusions (150 mg over 1–4 hours on day 1 and 450–600 mg over 1–3 hours on day 15 and week 24) in six dosing cohorts. The primary endpoint was B-cell depletion.

Results:

In all cohorts (N = 48), median B-cell depletion was >99% by week 4, maintained at weeks 24 and 48. Most common adverse events (AEs) were infusion-related reactions (all grade 1–2), with no apparent increased incidence at shorter infusion times. There were no AE-related discontinuations. At weeks 24 and 48, no T1 gadolinium-enhancing lesions (p = 0.003) and a 10.6% decrease in T2 lesion volume (p = 0.002) were detected. The annualized relapse rate was 0.07; 93% remained relapse free on study. Overall, 74% of patients had no evidence of disease activity (NEDA).

Conclusion:

Ublituximab was safely infused as rapid as 1 hour, producing robust B-cell depletion and profound reductions in magnetic resonance imaging (MRI) activity and relapses.

Efficacy of alemtuzumab over 6 years in relapsing-remitting multiple sclerosis patients who relapsed between courses 1 and 2: Post hoc analysis of the CARE-MS studies

BACKGROUND

Alemtuzumab is administered as two annual courses for relapsing-remitting multiple sclerosis (MS). Patients may relapse before completing the two-course regimen.

OBJECTIVE

The objective was to evaluate 6-year outcomes in patients who relapsed between alemtuzumab Courses 1 and 2 (early relapsers).

METHODS

Post hoc analysis of patients from the Comparison of Alemtuzumab and Rebif^® Efficacy in Multiple Sclerosis (CARE-MS) studies who enrolled in the extension.

RESULTS

Early relapsers (CARE-MS I: 15%; CARE-MS II: 24%) had more relapses in 1-2 years pre-alemtuzumab and higher mean baseline Expanded Disability Status Scale score than patients without relapse. Their annualized relapse rate declined from Year 1 (CARE-MS I: 1.3; CARE-MS II: 1.2) to Year 2 following Course 2 (0.3; 0.5) and remained low thereafter. Over 6 years, 60% remained free of 6-month confirmed disability worsening; 24% (CARE-MS I) and 34% (CARE-MS II) achieved 6-month confirmed disability improvement. During Year 6, 69% (CARE-MS I) and 68% (CARE-MS II) were free of magnetic resonance imaging (MRI) disease activity. Median percent yearly brain volume loss (Year 1: -0.67% (CARE-MS I); -0.47% (CARE-MS II)) declined after Course 2 (Year 6: -0.24%; -0.13%).

CONCLUSION

Early relapsers' outcomes improved after completing the second alemtuzumab course. These findings support administering the approved two-course regimen to maximize clinical benefit.

CLINICALTRIALS.GOV REGISTRATION NUMBERS

CARE-MS I, II, extension: NCT00530348, NCT00548405, NCT00930553.

Patients transitioning from non-pegylated to pegylated interferon beta-1a have a low risk of new flu-like symptoms: ALLOW phase 3b trial results

Background

Flu-like symptoms are common adverse events associated with interferon beta relapsing multiple sclerosis therapies.

Objectives

To evaluate the incidence and severity of flu-like symptoms after transitioning from non-pegylated interferons to peginterferon beta-1a and assess flu-like symptom mitigation using naproxen.

Methods

ALLOW was a phase 3b open-label study in relapsing multiple sclerosis patients. Patients had received non-pegylated interferon for 4 or more months immediately before beginning a 4-week screening period. At baseline, patients switched to peginterferon beta-1a and were randomly assigned (1:1) to continue their current flu-like symptoms management regimen or start twice-daily naproxen 500 mg for 8 weeks. Patients then switched to their preferred regimen and were followed for 48 weeks in total.

Results

Of 201 patients, 89.6% did not experience new/worsening flu-like symptoms during their first 8 weeks on peginterferon beta-1a. Flu-like symptom severity remained low in current-regimen and naproxen patients, with no significant between-group differences. Median flu-like symptom duration per injection was 3.2 hours longer with peginterferon beta-1a versus prior interferon, but the 4-week cumulative duration was reduced 49–78%. No new safety signals were identified.

Conclusion

Most patients who switched from non-pegylated interferon to peginterferon beta-1a did not experience new/worsening flu-like symptoms. Flu-like symptom duration per injection increased, but the cumulative duration significantly decreased. These data may inform flu-like symptom management guidance.

Infection risk with alemtuzumab decreases over time: pooled analysis of 6-year data from the CAMMS223, CARE-MS I, and CARE-MS II studies and the CAMMS03409 extension study

Background:

Reduced MS disease activity with alemtuzumab versus subcutaneous interferon beta-1a (SC IFNB-1a) in core phase 2/3 studies was accompanied by increased incidence of infections that were mainly nonserious and responsive to treatment. Alemtuzumab efficacy was durable over 6 years.

Objective:

To evaluate infections over 6 years in alemtuzumab-treated patients.

Methods:

Three randomized trials (CAMMS223, Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis (CARE-MS) I, and CARE-MS II) compared two courses of alemtuzumab 12 mg with SC IFNB-1a 44 μg in patients with active relapsing-remitting MS. An extension study (CAMMS03409) provided further evaluation and as-needed alemtuzumab retreatment.

Results:

Infections occurred more frequently with alemtuzumab 12 mg than SC IFNB-1a during Years 1 (58.7% vs 41.3%) and 2 (52.6% vs 37.7%), but declined for alemtuzumab-treated patients in Years 3 (46.6%), 4 (42.8%), 5 (40.9%), and 6 (38.1%). Serious infections were uncommon (1.0%–1.9% per year). Infections were predominantly (>95%) mild to moderate and included upper respiratory tract infections, urinary tract infections, and mucocutaneous herpetic infections. Prophylactic acyclovir reduced herpetic infections. Lymphocyte counts after alemtuzumab therapy did not predict infection risk.

Conclusion:

Infections with alemtuzumab were mostly mild to moderate and decreased over time, consistent with preservation of components of protective immunity.

Ease of use of two autoinjectors in patients with multiple sclerosis treated with interferon beta-1a subcutaneously three times weekly: results of the randomized, crossover REDEFINE study

BACKGROUND

For interferon beta-1a subcutaneously three times weekly (IFN β-1a SC tiw), administration options include manually injected prefilled syringes; a preassembled, single-use autoinjector; and a reusable autoinjector. This study evaluated patient-perceived ease of use of two injection devices.

RESEARCH DESIGN AND METHODS

REDEFINE, a Phase IV, multicenter crossover study, randomized patients with multiple sclerosis and ≥5 weeks' IFN β-1a 44 μg SC tiw use to 4 weeks using a single-use autoinjector, then 4 weeks using a reusable autoinjector, or vice versa. The primary endpoint was the proportion rating each 'easy' or 'very easy', with/without regard to previous device experience.

RESULTS

Of 97 randomized patients, 29 had most recent experience with manual injection; 23 with single-use autoinjector; and 45 with reusable autoinjector. 68.4% found using the single-use autoinjector very easy or easy, versus 77.9% for the reusable device (difference -9.5%; p = 0.200). 40.0% versus 29.5% found the respective devices very easy (difference 10.5%; p = 0.203).

CONCLUSIONS

Most patients found both autoinjectors easy or very easy to use. Having two viable options may help accommodate patient preferences. Ease of administration and patient satisfaction relates to adherence; satisfied patients may more likely be adherent.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT02019550).

Review: Induced pluripotent stem cell models of frontotemporal dementia

The increasing prevalence of dementia in the ageing population combined with the lack of treatments and the burden on national health care systems globally make dementia a public health priority. Despite the plethora of important research findings published over the past two decades, the mechanisms underlying dementia are still poorly understood and the progress in pharmacological interventions is limited. Recent advances in cellular reprogramming and genome engineering technologies offer an unprecedented new paradigm in disease modeling. Induced pluripotent stem cells (iPSCs) have enabled the study of patient-derived neurons in vitro, a significant progress in the field of dementia research. The first studies using iPSCs to model dementia have recently emerged, holding promise for elucidating disease pathogenic mechanisms and accelerating drug discovery. In this review, we summarize the major findings of iPSC-based studies in frontotemporal dementia (FTD) and FTD overlapping with amyotrophic lateral sclerosis (FTD/ALS). We also discuss some of the main challenges in the use of iPSCs to model complex, late-onset neurodegenerative diseases such as dementias.

Subcutaneous peginterferon β-1a injection-site reaction experience and mitigation: Delphi analysis of the ALLOW study

AIM

The objective of this Delphi analysis was to obtain consensus on injection-site reaction (ISR) experience and mitigation strategies for patients with relapsing-remitting multiple sclerosis switching from nonpegylated interferons (IFNs) to peginterferon β-1a in the ALLOW Phase IIIb trial using a three-step approach.

METHODS

Study investigators and coordinators from investigative sites enrolling four or more patients in ALLOW participated in three rounds of questionnaires and interviews.

RESULTS

Respondents (n = 37) agreed that the most common ISR, erythema, was not disruptive to daily activities. Patient education, as a conversation with a clinician about ISR potential, was recommended.

CONCLUSION

The consensus of Delphi respondents on ISR experience and ISR management after switching from nonpegylated IFNs to peginterferon β-1a can help inform treatment decisions and manage patient expectations.

The state of multiple sclerosis: current insight into the patient/health care provider relationship, treatment challenges, and satisfaction

BACKGROUND

Managing multiple sclerosis (MS) treatment presents challenges for both patients and health care professionals. Effective communication between patients with MS and their neurologist is important for improving clinical outcomes and quality of life.

METHODS

A closed-ended online market research survey was used to assess the current state of MS care from the perspective of both patients with MS (≥18 years of age) and neurologists who treat MS from Europe and the US and to gain insight into perceptions of treatment expectations/goals, treatment decisions, treatment challenges, communication, and satisfaction with care, based on current clinical practice.

RESULTS

A total of 900 neurologists and 982 patients completed the survey, of whom 46% self-identified as having remitting-relapsing MS, 29% secondary progressive MS, and 11% primary progressive MS. Overall, patients felt satisfied with their disease-modifying therapy (DMT); satisfaction related to comfort in speaking with their neurologist and participation in their DMT decision-making process. Patients who self-identified as having relapsing-remitting MS were more likely to be very satisfied with their treatment. Top challenges identified by patients in managing their DMT were cost, side effects/tolerability of treatment, and uncertainty if treatment was working. Half of the patients reported skipping doses, but only 68% told their health care provider that they did so.

CONCLUSION

Several important differences in perception were identified between patients and neurologists concerning treatment selection, satisfaction, expectations, goals, and comfort discussing symptoms, as well as treatment challenges and skipped doses. The study results emphasize that patient/neurologist communication and patient input into the treatment decision-making process likely influence patient satisfaction with treatment.

Characterization of Contractile Activity and Intracellular Ca2+ Signalling in Mouse Myometrium

OBJECTIVE

To characterize the contractile responses of mouse myometrium, the associated calcium (Ca2+) changes and the role of the sarcoplasmic reticulum (SR), and to better understand excitation contraction coupling in this tissue.

METHODS

Strips of longitudinal myometrium were used, and Ca2+ was measured after loading with Indo-1.

RESULTS

Intracellular Ca2+ transients, produced by Ca2+ entry, preceded phasic spontaneous contractions. Depolarization with high potassium concentration significantly increased the amplitude of the contractions and transformed the pattern of activity from phasic to tonic, with accompanying changes in intracellular Ca2+ concentration ([Ca2+]i). Oxytocin significantly stimulated contractile activity and [Ca2+]i above the level occurring spontaneously. Thus all forms of contractile activity were closely correlated with Ca2+. When the SR was emptied using a blocker of the SR calcium-adenosinetriphosphatase, cyclopiazonic acid, spontaneous Ca2+ and force transients increased greatly in frequency and amplitude. Ryanodine, a blocker of Ca(2+)-induced Ca2+ release (CICR), did not impair activity. In the absence of external Ca2+, oxytocin was able to release Ca2+ from the SR through IP3 but produced only a small increase in force, demonstrating a requirement for Ca2+ entry as part of the mechanism of agonist action.

CONCLUSION

Mouse myometrium, (1) produces contractile activity reflecting changes in [Ca2+]i irrespective of the stimulus, (2) has a significant SR Ca2+ content releasable by agonists but not CICR, (3) has an SR acting to inhibit spontaneous activity, and (4) behaves qualitatively similarly to human and rat myometrium in major aspects of excitation contraction coupling and is therefore a useful model tissue.

Review: Insights into molecular mechanisms of disease in neurodegeneration with brain iron accumulation: unifying theories

Neurodegeneration with brain iron accumulation (NBIA) is a group of disorders characterized by dystonia, parkinsonism and spasticity. Iron accumulates in the basal ganglia and may be accompanied by Lewy bodies, axonal swellings and hyperphosphorylated tau depending on NBIA subtype. Mutations in 10 genes have been associated with NBIA that include Ceruloplasmin (Cp) and ferritin light chain (FTL), both directly involved in iron homeostasis, as well as Pantothenate Kinase 2 (PANK2), Phospholipase A2 group 6 (PLA2G6), Fatty acid hydroxylase 2 (FA2H), Coenzyme A synthase (COASY), C19orf12, WDR45 and DCAF17 (C2orf37). These genes are involved in seemingly unrelated cellular pathways, such as lipid metabolism, Coenzyme A synthesis and autophagy. A greater understanding of the cellular pathways that link these genes and the disease mechanisms leading to iron dyshomeostasis is needed. Additionally, the major overlap seen between NBIA and more common neurodegenerative diseases may highlight conserved disease processes. In this review, we will discuss clinical and pathological findings for each NBIA-related gene, discuss proposed disease mechanisms such as mitochondrial health, oxidative damage, autophagy/mitophagy and iron homeostasis, and speculate the potential overlap between NBIA subtypes.

Progress in understanding electro-mechanical signalling in the myometrium

In this review, we give a state-of-the-art account of uterine contractility, focussing on excitation-contraction (electro-mechanical) coupling (ECC). This will show how electrophysiological data and intracellular calcium measurements can be related to more modern techniques such as confocal microscopy and molecular biology, to advance our understanding of mechanical output and its modulation in the smooth muscle of the uterus, the myometrium. This new knowledge and understanding, for example concerning the role of the sarcoplasmic reticulum (SR), or stretch-activated K channels, when linked to biochemical and molecular pathways, provides a clearer and better informed basis for the development of new drugs and targets. These are urgently needed to combat dysfunctions in excitation-contraction coupling that are clinically challenging, such as preterm labour, slow to progress labours and post-partum haemorrhage. It remains the case that scientific progress still needs to be made in areas such as pacemaking and understanding interactions between the uterine environment and ion channel activity.

Oxytocin: its mechanism of action and receptor signalling in the myometrium

Oxytocin is a nonapeptide hormone that has a central role in the regulation of parturition and lactation. In this review, we address oxytocin receptor (OTR) signalling and its role in the myometrium during pregnancy and in labour. The OTR belongs to the rhodopsin-type (Class 1) of the G-protein coupled receptor superfamily and is regulated by changes in receptor expression, receptor desensitisation and local changes in oxytocin concentration. Receptor activation triggers a number of signalling events to stimulate contraction, primarily by elevating intracellular calcium (Ca(2+) ). This includes inositol-tris-phosphate-mediated store calcium release, store-operated Ca(2+) entry and voltage-operated Ca(2+) entry. We discuss each mechanism in turn and also discuss Ca(2+) -independent mechanisms such as Ca(2+) sensitisation. Because oxytocin induces contraction in the myometrium, both the activation and the inhibition of its receptor have long been targets in the management of dysfunctional and preterm labours, respectively. We discuss current and novel OTR agonists and antagonists and their use and potential benefit in obstetric practice. In this regard, we highlight three clinical scenarios: dysfunctional labour, postpartum haemorrhage and preterm birth.

Bombesin Receptor Gene Expression in Rat Embryos: Transient GRP-R Gene Expression in the Posterior Pituitary

Bombesin-like peptides can stimulate growth of cultured cells derived from ectoderm, endoderm, or mesenchyme and act as autocrine growth factors in some lung carcinoma cell lines. Recently, cDNA clones for two mammalian bombesin receptors (BN-R), gastrin-releasing peptide receptor (GRP-R) and neuromedin B receptor (NMB-R), were characterized and shown to be present in distinct regions of the central nervous system at birth. To determine whether the spatial and/or temporal expression of BN-R genes correlated with tissue-specific or organ-specific developmental events, the prenatal distribution of GRP-R and NMB-R mRNAs were compared by in situ hybridization histochemistry. The differential expression of these two BN-R genes was striking. From early embryonic stages, GRP-R mRNA was expressed in various organs, including nervous, urogenital, respiratory, and digestive systems. In contrast, NMB-R gene expression was detected at later embryonic stages and the distribution of expression was much more limited. In most tissues, after onset of expression, both receptor mRNAs showed a steady increase in expression throughout development. However, transient expression of GRP-R mRNA was seen in the posterior pituitary. Intense GRP-R labeling of posterior pituitary cells was seen from E12 to E20, but at birth, GRP-R mRNA levels were undetectable. These results suggest that (a) two BN-R subtypes mediate independent functions during development, (b) ontogenesis of multiple organs may involve GRP-R mediated events, and (c) GRP-R gene expression is involved in differentiation/development of the pituitary gland.

Diabetes is associated with impairment of uterine contractility and high Caesarean section rate

AIMS/HYPOTHESIS

The prevalence of births worldwide complicated by diabetes mellitus is increasing. In the UK, for example, <25% of diabetic women have a non-instrumental vaginal delivery. Strikingly, more than half the Caesarean sections (CS) in these patients are non-elective, but the reasons for this are not understood. We have tested the hypothesis that poor myometrial contractility as a consequence of the disease contributes to this high CS rate.

METHODS

We compared spontaneous, high K depolarisation and oxytocin-induced contractions from diabetic and matched control patients having an elective CS. To investigate the mechanism of any differences we measured intracellular Ca, and performed western blotting and compared the tissues histologically.

RESULTS

There was significantly decreased contraction amplitude and duration in uteri from diabetic compared with control patients, even when possible confounders such as BMI were analysed. Reduced intracellular calcium signals and expression of calcium entry channels were found in uteruses from diabetic patients, which, along with a reduction in muscle content found on histological examination, could explain the reduced force. Myometrium from diabetic patients was responsive to oxytocin, but still did not reach the levels found in non-diabetic patients.

CONCLUSIONS/INTERPRETATIONS

These are the first data investigating myometrium in diabetic patients and they support the hypothesis that there is poorer contractility even in the presence of oxytocin. The underlying mechanism is related to reduced Ca channel expression and intracellular calcium signals and a decrease in muscle mass. We conclude that these factors significantly contribute to the increased emergency CS rate in diabetic patients.

In vitro myometrial contractility reflects indication for caesarean section

OBJECTIVE

To assess the extent to which in vitro measurements of myometrial contractility reflect the clinical indication for caesarean section.

DESIGN

A prospective, observational hypothesis-generating study.

SETTING

Women were recruited from Liverpool Women's NHS Foundation Trust and experiments were performed in the Physiology Department at the University of Liverpool.

POPULATION

Myometrial samples were taken from women undergoing a caesarean section during labour (n = 50) or from women having a repeat nonlabouring caesarean section (n = 70).

METHODS

The demographic characteristics of the women and indications for current and previous caesarean sections were recorded. The force, frequency and duration of spontaneous contractions of myometrial strips, and changes in the intracellular calcium concentration of the strips, were measured. Kruskall-Wallis and post hoc tests were used to assess the significance of differences between groups.

RESULTS

Samples from women whose caesarean section was for fetal distress/acidosis (scalp pH <7.2) contracted with more force than those from women whose caesarean section was for delay in the first stage of labour (P < 0.001). For repeat, nonlabouring caesarean sections, samples from women whose first caesarean section was for fetal distress/acidosis also contracted with more force than did samples from women whose first caesarean section was for delay in the first stage of labour (P = 0.03).

CONCLUSIONS

These findings suggest that the myometrium contracts with greater force in women who have a caesarean section for fetal distress.

Maternal obesity and labour complications following induction of labour in prolonged pregnancy

OBJECTIVE

To investigate the effect of maternal obesity on mode of delivery following induction of labour (IOL) for prolonged pregnancy and subsequent intrapartum and neonatal complications.

DESIGN

Retrospective (historical) cohort study.

SETTING

Liverpool Women's Hospital NHS Foundation Trust, UK.

POPULATION

A total of 29, 224 women with singleton pregnancies between 2004 and 2008 of whom 3076 had a prolonged pregnancy (defined as ≥290 days or 41(+3) weeks of gestation) and received IOL.

METHODS

Kruskal-Wallis test, chi-square test and multivariable logistic regression.

MAIN OUTCOME MEASURES

Mode of delivery and risk of delivery and neonatal complications in obese verses non-obese women following IOL.

RESULTS

Obese women had a significantly higher rate of IOL ending in caesarean section compared with women of normal weight following IOL (38.7% versus 23.8% primiparous; 9.9% versus 7.9% multiparous women, respectively); however, length of labour, incidence of postpartum haemorrhage and third-degree tear, rate of low cord blood pH, low Apgar scores and shoulder dystocia were similar in all body mass index categories. Complications included a higher incidence of fetal macrosomia and second-degree, but not third-degree, tear in primiparous women.

CONCLUSIONS

Higher maternal body mass index at booking is associated with an increased risk of prolonged pregnancy and increased rate of IOL. Despite this, more than 60% of obese primiparous and 90% of multiparous women with prolonged pregnancies who were induced achieved vaginal delivery and labour complications in the obese women with prolonged pregnancies were largely comparable to those of normal weight women with prolonged pregnancies. Our data suggest that IOL for prolonged pregnancy in obese women is a reasonable and safe management option.

From nose to brain: development of gonadotrophin-releasing hormone-1 neurones

Gonadotrophin-releasing hormone-1 (GnRH-1) is essential for mammalian reproduction, controlling release of gonadotrophins from the anterior pituitary. GnRH-1 neurones migrate from the nasal placode into the forebrain during development. Although first located within the nasal placode, the embryonic origin/lineage of GnRH-1 neurones is still unclear. The migration of GnRH-1 cells is the best characterised example of neurophilic/axophilic migration, with the cells using a subset of olfactory-derived vomeronasal axons as their pathway and numerous molecules to guide their movement into the forebrain. Exciting work in this area is beginning to identify intersecting pathways that orchestrate the movement of these critical neuroendocrine cells into the central nervous system, both spatially and temporally, through a diverse and changing terrain. Once within the forebrain, little is known about how the axons target the median eminence and ultimately secrete GnRH-1 in a pulsatile fashion.

Sex hormones and excitation-contraction coupling in the uterus: the effects of oestrous and hormones

In this review, we examine how far the increased understanding that we have of the events in excitation contraction can explain the effects of the oestrous cycle and sex hormones on uterine function. Observational studies of electrical and mechanical activity in the rat myometrium have shown a relative quiescence during pro-oestrous, with little propagation of any electrical events. Thus, uterine activity can be said to approximately inversely reflect plasma 17beta-oestradiol concentrations. We show that Ca(2+) signalling and mechanical activity are greatest in metoestrous and dioestrous compared to pro-oestrous and oestrous. These data are discussed in terms of hormonal effects on Ca(2+) and K(+) channels. Finally, the influence of sex hormones on lipid rafts and caveolae are considered and discussed in relation to recent findings on their role in uterine signalling and contractility, and cholesterol levels and obesity.

Temporal migration of gonadotrophin-releasing hormone-1 neurones is modified in GAD67 knockout mice

Gonadotrophin-releasing hormone (GnRH-1) neurones reside in the forebrain and regulate gonadal function via the hypothalamic-pituitary-gonadal axis. Disruption of this axis results in reproductive dysfunction. During embryonic development, GnRH-1 neurones migrate from the nasal pit through the nasal/forebrain junction (NFJ) into the developing brain. Prenatally gamma-aminobutyric acid (GABA) is excitatory and has been shown to play a role in nervous system development. Both in vivo and in vitro experiments suggest that GABA inhibits migration of GnRH-1 neurones. The present study examines the migration of GnRH-1 neurones in GAD67 knockout (KO) mice to further elucidate the role of GABA on GnRH-1 neuronal development. Three stages were examined, embryonic day (E)12.5, E14.5 and E17.5. GnRH-1 cell number and location were analysed by immunocytochemistry and in situ hybridisation histochemistry. The total number of GnRH-1 immunopositive cells was similar between wild-type (WT) and KO mice. However, significant differences were found in the overall distribution of GnRH-1 immunopositive cells in GAD67 KO compared to WT mice at all stages. Subsequent analysis by area revealed differences occurred at the NFJ with an increase in GnRH-1 cells in GAD67 KO at E14.5 and a decrease in GnRH-1 cells in GAD67 KO at E17.5. Comparable counts for cells expressing GnRH-1 transcript and protein were obtained. These data indicate that attenuated levels of GABA accelerate GnRH-1 cell migration in nasal areas as well as movement of GnRH-1 cells into the central nervous system at the NFJ.

Intravenous conscious sedation in children for outpatient dentistry

The use of general anaesthesia for dental treatment in the NHS outside hospitals has changed over time. Although deaths are uncommon during or immediately after general anaesthesia for dental treatment, they are more likely to occur than with other methods of pain and anxiety reduction, such as local anaesthesia and conscious sedation. Inquiries into recent anaesthetic deaths in dental practice have been critical of the standard of care provided in areas such as pre-operative assessment, monitoring, resuscitation and transfer to specialist critical care facilities.

Nasal embryonic LHRH factor (NELF) expression within the CNS and PNS of the rodent

A novel protein (NELF) was identified screening embryonic luteinizing hormone releasing hormone (LHRH) neurons at different migrational states. Experiments in vitro revealed that NELF functions in olfactory axon outgrowth and subsequently alters LHRH neuronal migration. NELF was not restricted to LHRH neurons in the developing rodent. Multiple CNS and PNS tissues expressed this gene. To characterize the specific regions that express NELF in situ hybridization histochemistry was performed. Within the CNS, cells in the cortex, hippocampus, thalamus and olfactory regions express NELF pre- and postnatally.

Poor uterine contractility in obese women

OBJECTIVE

The aim of the study was to elucidate the reason for the high rate of caesarean section in obese women. We examined the following hypotheses: (1) obese women have a high incidence of complications related to poor uterine contractility--caesarean section for dysfunctional labour and postpartum haemorrhage. 2) The myometrium from obese women has less ability to contract in vitro.

DESIGN

First, a clinical retrospective analysis of data from 3913 completed singleton pregnancies was performed. Secondly, in a prospective study the force, frequency and intracellular [Ca(2+)] flux of spontaneously contracting myometrium were related to the maternal body mass index.

SETTING

Liverpool Women's Hospital and University of Liverpool.

POPULATION

The clinical study involved all women who delivered in one hospital in 2002. The in vitro study myometrial biopsies were obtained from 73 women who had elective caesarean section at term.

RESULTS

Maternal obesity carried significant risk of caesarean section in labour that was highest for delay in the first stage of labour (OR 3.54). The increased risk of caesarean section in obese women largely occurred in women with normal- and not with high-birthweight infants. Obese women delivering vaginally had increased risk of prolonged first stage of labour and excessive blood loss. Myometrium from obese women contracted with less force and frequency and had less [Ca(2+)] flux than that from normal-weight women.

CONCLUSIONS

We suggest that these findings indicate that obesity may impair the ability of the uterus to contract in labour.

Distribution of AQP2 and AQP3 water channels in human tissue microarrays

The objective of this investigation was to use semi-quantitative immunohistochemistry to determine the distribution and expression levels of AQP2 and AQP3 proteins in normal human Tissue MicroArrays. Expression of the vasopressin regulated AQP2 was observed in a limited number of tissues. AQP2 was prominent in the apical and subapical plasma membranes of cortical and medullary renal collecting ducts. Surprisingly, weak AQP2 immunoreactivity was also noted in pancreatic islets, fallopian tubes and peripheral nerves. AQP2 was also localized to selected parts of the central nervous system (ependymal cell layer, subcortical white matter, hippocampus, spinal cord) and selected cells in the gastrointestinal system (antral and oxyntic gastric mucosa, small intestine and colon). These findings corroborate the restricted tissue distribution of AQP2. AQP3 was strongly expressed in many of the human tissues examined particularly in basolateral membranes of the distal nephron (medullary collecting ducts), distal colon, upper airway epithelia, transitional epithelium of the urinary bladder, tracheal, bronchial and nasopharyngeal epithelium, stratified squamous epithelial cells of the esophagus, and anus. AQP3 was moderately expressed in basolateral membranes of prostatic tubuloalveolar epithelium, pancreatic ducts, uterine endometrium, choroid plexus, articular chondrocytes, subchondral osteoblasts and synovium. Low AQP3 levels were also detected in skeletal muscle, cardiac muscle, gastric pits, seminiferous tubules, lymphoid vessels, salivary and endocrine glands, amniotic membranes, placenta and ovary. The abundance of basolateral AQP3 in epithelial tissues and its expression in many non-epithelial cells suggests that this aquaglyceroporin is a major participant in barrier hydration and water and osmolyte homeostasis in the human body.

Developmental changes in GABA receptor subunit composition within the gonadotrophin-releasing hormone-1 neuronal system

It is becoming increasingly evident that GABA plays an important role in the regulation of gonadotrophin-releasing hormone (GnRH)-1 neurones via the GABAA receptor. The aim of the present study was to characterise expression of the GABAA receptor within the GnRH-1 system across development. The expression pattern of five GABAAalpha subunits and one GABAAbeta subunit was first examined within individual GnRH-1 neurones by the polymerase chain reaction. A significant increase in the expression of GABAAalpha2 and a significant decrease in the expression of GABAAalpha6 over time were found. Of the other subunits examined, two (alpha1 and alpha3) showed no differences in expression and two (alpha4 and beta3) showed variable low incidence of expression. Given the reciprocal relationship of alpha2 and alpha6 expression, we hypothesised that there is a developmental switch in the expression of these subunits in GnRH-1 neurones. To investigate this hypothesis, single- and double-label immunocytochemistry for GABAAalpha2 and alpha6 and GnRH-1 was performed in tissue from ages E12.5 to adulthood, as well as in nasal explants. We show that GABAAalpha2 and alpha6 are present in the GnRH-1 neuronal system both in vivo and in vitro and that the levels of expression are altered as a function of age.