Download presentation
Presentation is loading. Please wait.
Published byTheodore Fisher Modified over 9 years ago
1
Status of the Trial for Thymectomy in Nonthymomatous MG Patients Receiving Prednisone (MGTX) Henry J. Kaminski Department of Neurology & Psychiatry Saint Louis University
2
Outline Rationale for the MGTX trial Trial structure What has been learned The near future
3
Evidence Based Review Evidence-based AAN Practice Parameter 28 Class II studies (Class II. Evidence provided by well-designed observational studies with concurrent controls, e.g., case–control and cohort studies), published between 1953-1998 21 MG cohorts 4136 surgical pts; 4354 non-surgical pts Majority used transsternal approach F/U mean range 3-28 years No blinded assessments
4
AAN Practice Parameter Conclusions and recommendations Conclusions and recommendations Benefit of thymectomy not established conclusively Benefit of thymectomy not established conclusively Recommended as treatment option Recommended as treatment option Controlled trial needed Controlled trial needed
5
History of MGTX October 2000 at the American Neurological Association 1st Investigator Meeting organized by John Newsom-Davis Gil Wolfe receives Muscular Dystrophy Association (USA) funds for planning process First submission to the National Institutes of Health (February 1, 2001) and Medical Research Council
6
History of MGTX Fourth submission to the National Institutes of Health (November 15, 2004) Funding approved (September 2005) Final protocol revisions performed in collaboration with the NIH NIH supports Biomarker Ancillary Study (March 2006)
7
Thymectomy trial in non-thymomatous MG patients on prednisone (1R01 NS42685) Present Leadership Gil Wolfe, MD (Study Chair) Gary Cutter, PhD (Director, DCC,) Immaculada Aban, PhD (Deputy Director, DCC) Henry Kaminski, MD (Director Biomarker study, Study Vice Chair) Alfred Jaretzki, MD (Surgical Chair) Greg Minisman (Project Manager)
8
History of MGTX March 2006 Training meetings held in San Francisco and Oxford April 2006 first center obtains full regulatory approval July 2006 first patient randomized
9
Inclusion criteria AChR binding Ab pos (≥0.5) MGFA Class 2-4; disease duration < 5 years Age at least 18 and < 65 years Optimal anti-cholinesterase dose Prednisone naïve or not Main exclusion criteria Previous thymectomy or sternotomy or thoracotomy Immunosuppressive therapy (x prednisone) within last year Rituximab at any time Medically or psychiatrically unfit for thymectomy Chest CT or MR evidence of thymoma Pregnancy or lactation, or considering becoming pregnant Current prednisone > 0.75 mg/kg or 50 mg/d (or AD equivalent) MGTX Protocol
10
RANDOMIZATION Surgery prednisone 1.5 mg/kg AD prednisone 1.5 mg/kg AD Minimal Manifestations prednisone taper Minimal Manifestations prednisone taper 1° Composite AUQTC and AUDTC, at 3 years at 3 years 2° prednisone AUDTC at 1,2 years Time to Minimal Manifestations Time to Minimal Manifestations ∆QMG, MG-ADL at 1,2,3 years ∆QMG, MG-ADL at 1,2,3 years ∆SF-36 at 1,2,3 years ∆SF-36 at 1,2,3 years hospital days at 2, 3 years hospital days at 2, 3 years outcomemeasures MGTX Trial
11
MGTX Protocol Composite primary outcome Prednisone requirements (AUDTC-Area Under the Dose Time Curve) Clinical response (AUQ MG TC) Blinded evaluator (BE) Study specific adverse events
12
Sample Size 90% power, P=0.05, AUDTC at 3 years is 30% of the baseline mean, the trial requires 60 subjects in each arm or 120 total. 20% dropouts over 3 years yields a sample size of 75 per group or a 150 total. In order to provide a reasonable test of the effect for those pre-medicated with prednisone versus those not on prednisone, sample size increased to 100 per group. This allows for approximately 50 patients in each subgroup. For the 30% difference, 50 patients would yield a power of 84% within each subgroup. Total Sample Size of 200.
13
MGTX Protocol Minimal Manifestation Status (MGFA Criteria Neurology 2000;55:16 ) No symptoms or functional limitations from MG but some weakness present on careful examination QMG score <14; ≤ baseline value Treatment options Azathioprine or other IS agent allowed if MMS not reached by 1 year OR severe prednisone-related AEs via protocol deviation
14
Thymectomy Procedure
15
Biomarker Ancillary Study Identify biomarkers (genes or proteins) associated with the diagnosis of MG SNP, genomic profile, proteomic profile, autoAb profile, thymic pathology Angela Vincent Alex Marx and Philip Strobel Identify biomarkers through genomic and proteomic profiling associated with clinical parameters Identify biomarkers associated with thymic pathology as assessed by tissue array profiling
16
Secondary Measures Medication-associated adverse symptoms questionnaire score. Change in QMG and MG-ADL over time and at months 12, 24 and 36 Time from day 0 to reach initial MM status MM status at months 12, 24 and 36 Actual prednisone dose at month 36 Quality of life assessment (SF 36) at months 12, 24 and 36 Cumulative days in hospital for treatment of, or complications related to, MG by months 24 and 36. Number of plasma exchanges and IVIG infusions, and total dose of IVIG from day 0 to month 36
17
67 Actively Recruiting Centers
18
Patient Screening and Randomization 5,760 patients (3,162 from centers outside the US) and 2,430 from US Centers) as of September 2009 170 eligible patients 89 refused 81 randomized (19 from US Centers) 69% of eligible US patients refused while 44% of eligible patients outside the US refused.
19
Reasons for Refusal 41Does not wish thymectomy 17Does wish thymectomy 15Does not wish to take corticosteroids 14Family advises against participation 11Trial too demanding 10Wary of research trials 9Cannot commit to 36 month trial 2wishes a less invasive procedure than thymectomy
20
Randomized Patients 58% are women Mean age: 34 years, sd 11.68 Class II 64% Class III 33% Class IV 3% DROP OUTS 5 Patients-much lower than expected
22
Leading Centers Buenos Aires, Argentina (Claudio Mazia, PI) 14 patients Santiago, Chile (Gabriel Cea) 7 patients Vancouver, British Columbia, Canada (Joel Oger) 7 patients Cape Town, South Africa (Jeannine Heckmann) with 5 patients.
23
MGTX Challenges Regulatory clearance US sites: 9.67 ± 0.74 months Non-US sites: 13.4 ± 0.96 months p=0.0175 IRB/EC approval US sites: 4.4 months Non-US sites: 5.3 months Subcontract approval US sites: 7.86 months Non-US sites: 8.65 months Native language translations Insistence on local currency Aban et al. J Neuroimmunol 2008; 201-202:80-84
24
MGTX Challenges IRB/Ethics committees Local practices (Italy and birth control) MREC approval in UK Japan, Netherlands, Taiwan, UK would not permit use of prednisone originating in US Federalwide Assurance (FWA) Via US Office of Human Research Protections of DHHS Non-US administrators may not be fluent in English Renewal q3 yrs US State Dept. clearance S. America, Asia delays (17 mos for Brazil) Training and certification Now done locally by Project Manager Certification tests for neurologists and surgeons Data Entry System certification
25
John Newsom-Davis (1932-2007) The Leadership Team, colleagues at the NIH, and all participating investigators continue to work towards successful completion.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.