NIC-PD (A Randomized, Placebo-controlled, Double-blind, Multi-centre Trial to Assess the Disease-modifying Potential of Transdermal NICotine in Early Parkinson’s Disease) in Germany and the USA.
Status, January 29, 2018: Manuscript Phase
The Parkinson Study Group (PSG), under the direction of Wolfgang Oertel, MD (Philipps University, Marburg Germany), and James Boyd, MD (University of Vermont), conducted a randomized, placebo-controlled, double-blind, multi-center trial to assess the disease-modifying potential of transdermal nicotine in early Parkinson’s disease in Germany and the USA. The purpose of the study was to demonstrate that transdermal nicotine treatment retards disease progression as measured by change in the Unified Parkinson’s Disease Rating Scale (UPDRS) (part I, II, III) score between baseline and after 52 weeks of study treatment plus two more months following a wash-out period (60 weeks). Approximately 20 research centers in the United States and Germany enrolled approximately 160 subjects for 12 months each.
This study was conducted under two research grant awards from The Michael J. Fox Foundation one to Philipps University, Marburg, Germany and the other to the University of Rochester, Rochester, New York.
If you are interested in learning more about this study, please see the study on www.clinicaltrials.gov
Status, October 22, 2019: Analysis Phase
The Parkinson Study Group (PSG), under the direction of Tanya Simuni, MD (Northwestern University) conducted a multi-center, randomized, double-blind, placebo-controlled study of nilotinib in individuals with moderate to advanced Parkinson’s disease (PD). Nilotinib, a U.S. Food and Drug Administration (FDA)-approved treatment for chronic myelogenous leukemia, is one of many examples of a repurposed (or repositioned) drug for Parkinson’s.
The trial is registered on clinicaltrials.gov (NCT03205488). Results of the study will be presented at the MDS-PAS Congress, February 2020, in Miami.
NoMOFA (Validation of a Non-Motor Fluctuation Assessment Instrument (NoMoFA) for Parkinson’s Disease)
The study completed enrollment in December 2019. Data analysis has demonstrated that the questionnaire is valid and reliable. Additional Delphi Panel was convened and resulted in finalization of the questionnaire. The results of the study were presented as part of the Guided Poster Presentations at the 2020 MDS Virtual Congress in September 2020. The manuscript has been submitted for publication in the Movement Disorders Journal and is under review.
The Parkinson Study Group (PSG), in collaboration with Galit Kleiner, MD (ATC), Alberto Espay, MD (University of Cincinnati), Hubert Fernandez, MD (Cleveland Clinic), Alfonso Fasano, MD, PhD (TWH), Kelvin Chou, MD, PhD (University of Michigan), and Glenn Stebbins, PhD (Rush University), have developed a comprehensive questionnaire that assesses the presence of non-motor fluctuations (NMFs) in individuals with Parkinson’s disease (PD). The objectives of this validation study are to: (i) assess the scale’s internal consistency and item-to-total correlations; (ii) assess test-retest reliability; (iii) use factor analysis and reliability measures to guide item reduction; (iv) assess construct validity; (v) assess the scale’s ability to discriminate between static non-motor symptoms and non-motor symptoms which fluctuate; and (vi) estimate the relative distribution of cognitive, psychiatric, autonomic, sleep and sensory NMFs in PD patients with motor fluctuations and their impact on quality of life in Parkison’s disease.
The study is sponsored by Sunovion Pharmaceuticals and is registered on clinicaltrials.gov.
SURE-PD3 (A Phase 3, Randomized, Double-blind, Placebo-controlled Trial of Urate-elevating Inosine Treatment to Slow Clinical Decline in Early PD)
Closing out. Negative results of primary analysis presented at MJFF Therapeutics Conference 2019. Secondary analyses incorporating WGS data are in progress and will coordinate with STEADY-PD III analyses.
The Parkinson Study Group (PSG) conducted, under the direction of Michael Schwarzschild, MD PhD, a placebo-controlled, randomized, double-blind study to assess the disease-modifying potential of the drug inosine in people with early stage Parkinson’s disease (PD).
The Parkinson Study Group (PSG), under the direction of the SYNAPSE Steering Committee, conductedd a placebo-controlled, randomized, double-blind study called SYNAPSE: (SYN120 a Dual 5-HT6/5-HT2A Antagonist Proof of Concept Study to Evaluate Its Safety, Tolerability and Efficacy in Parkinson’s Disease Dementia), to assess the safety and efficacy of SYN120 in patients with Parkinson’s disease dementia (PDD) already treated with a stable dose of a cholinesterase inhibitor.
The BLIND-DATE trial (“BLINDed Withdrawal of Deprenyl in the DATATOP Extension”) examined the long-term effects of deprenyl on the course of levodopa-treated Parkinson’s disease. (See DATATOP in the Completed Clinical Trials section for the background and details of BLIND-DATE).
The PSG, under the sponsorship of Pharmacia & Upjohn, Inc. (Kalamazoo, MI), led by Ira Shoulson, MD, and Stanley Fahn, MD, conducted the study, CALM-PD (Comparison of the Agonist Pramipexole versus Levodopa on Motor Complications of Parkinson’s Disease). Enrollment of 301 subjects at 22 sites began in October 1996 and was completed August 1997. This parallel group, double-blind controlled trial is designed to compare the policies of initial treatment with pramipexole versus initial treatment with carbidopa/levodopa in Parkinson’s disease patients. The development of dopaminergic motor complications was the primary outcome of interest. This study also included ß-CIT SPECT measurements, an economic outcome substudy, and a quality-of-life instrument customized for Parkinson’s disease. Subjects were examined prospectively for at least 23.5 months, after which time they had the option of participating in the blinded extension of CALM-PD. Subjects concluded participation in CALMPD and its extension in August, 2001. The results of the CALM-PD study were published in JAMA on October 18, 2000.
DARE (Dyskinesias And Remacemide Effects), led by Anthony Lang, MD, Stanley Fahn, MD and Ira Shoulson, MD, and sponsored by Astra Pharmaceuticals, was a placebo-controlled study of subjects with Parkinson’s disease who have severe dyskinesias despite optimized antiparkinsonian medications. Enrollment of 39 subjects at five sites began in December 1997 and was completed in May 1998. A report summarizing the preliminary data from RAMP, REAL and DARE entitled “The Glutamate Antagonist Remacemide Improves Motor Performance in Levodopa-Treated Parkinson’s Disease” was presented at the 51st Annual Meeting of the American Academy of Neurology Scientific Session, April 21, 1999, in Toronto, Canada.
DATATOP AND ITS FOLLOW-ON PROTOCOLS
DATATOP (Deprenyl And Tocopherol Antioxidative Therapy Of Parkinsonism), led by Ira Shoulson, MD, and Stanley Fahn, MD, and sponsored by NINDS, is the largest and longest prospective controlled study of therapeutic interventions in Parkinson’s disease conducted in the world. It was the first of PSG’s multi-center trials. *(Click here to download the complete PDF.)
Evaluation of DOPASCAN™ in Parkinson’s Disease and Related Disorders
PSG, under the leadership of Kenneth Marek, MD, and John Seibyl, MD, and the sponsorship of Guilford Pharmaceuticals, Inc. (Baltimore, MD), conducted a five-center trial to examine DOPASCAN™, a SPECT imaging ligand, as a diagnostic marker for Parkinson’s disease. DOPASCAN™ is a radiotracer that binds to the dopamine transporter and provides a measure of the integrity of dopamine terminals. Enrollment and follow-up of 96 subjects at five sites was completed in December 1996. Data were published in abstract form in Movement Disorders and Journal of Nuclear Medicine and a full report is under review.
One of the most lingering and important questions in the therapeutics of PD is whether levodopa, the mainstay of treatment, has long-term beneficial or harmful effects on the progression of disease. A survey on treating patterns was conducted during the PSG/MDS Symposia in October 1995 and reported in October 1996 in Movement Disorders. An application was submitted to the National Institute of Health (NIH) in June 1996 for the ELLDOPA (Earlier versus Later LevoDOPA) placebo-controlled trial, which was reviewed favorably and awarded by the National Institute of Neurological Disorders and Stroke (NINDS-NIH) in January 1998. The ELLDOPA trial, under the direction of Stanley Fahn, MD, and Ira Shoulson, MD, began enrollment of 360 patients with early Parkinson’s disease at 35 PSG sites in October 1998. Subjects were followed for 40 weeks prior to a 17-day washout and final evaluation of the progression of disease. A ß-CIT SPECT study, funded by a grant to Kenneth Marek, MD, by the Department of Defense, was carried out in a sub-set of ELLDOPA subjects to assess a biological marker of the progression of Parkinson’s disease (loss of dopamine transporter binding sites). As of September 2001, enrollment was closed for the study with 361 subjects completing enrollment. The final subject visit is expected in June 2002 with analysis to follow. For additional information on the scientific rationale for this study, please see the 1999 publication in Archives of Neurology.
MOVE-PD (A Phase II Study to Evaluate the Safety and Efficacy of RM-131 in Patients With Parkinson’s Disease & Chronic Constipation)
Status, January 29, 2018: Primary paper published*
The Parkinson Study Group (PSG), under the direction of the MOVE-PD Steering Committee, conducted a clinical trial to test a new treatment for chronic constipation among Parkinson’s disease (PD) patients. Constipation is a common non-motor symptom of PD, which can cause extreme discomfort.
Researchers investigated how individuals with PD and chronic constipation respond to the drug RM-131, as compared to placebo. The study was originally sponsored by Rhythm Pharmaceuticals, Inc. (Boston, Massachusetts) with funding provided by The Michael J. Fox Foundation for Parkinson’s Research. PI: Ronald F. Pfeiffer, M.D.
*Click here to download the complete PDF.
For more information regarding this trial visit clinicaltrials.gov.
PATCH I (PArkinson’s Disease Transdermal Clinical Trial Helping to Assess SPM-962 Transdermal System (TDS) in Patients Not Receiving DopaminergicTherapy), led by Ira Shoulson, MD, and under the sponsorship of Schwarz Pharma Inc. (Meguon, WI and Monheim, Germany) conducted a Phase IIb efficacy, safety and tolerability study of the experimental dopamine agonist SPM-962, delivered as a transdermal patch system in patients with Parkinson’s disease who are not receiving dopaminergic therapy. Enrollment of 242 subjects at 28 sites began on November 15, 1999 and was completed in July, 2000.
Parkinson’s Disease On EsTrogen Replacement in the Menopause Years. Click here to view the trial record.
A randomized, double-blind, active (pramipexole 0.5 mg tid) and placebo controlled, efficacy study of pramipexole, given 0.5 mg and 0.75 mg bid over a 12-week treatment phase in early PD patients. Click here to view the trial record.
The Parkinson Study Group (PSG), in collaboration with two pharmaceutical companies, Cephalon, Inc. (West Chester, PA) and H. Lundbeck A/S (Valby-Copenhagen, Denmark), conducted a study for patients with early Parkinson’s disease called PRECEPT (Parkinson Research Examination of CEP1348 Trial). The goal of PRECEPT was to determine if the investigational drug CEP-1347 could slow the clinical progression of early Parkinson’s disease. The study assessed the safety and tolerability of different doses of CEP-1347 and also examined the long-term effects of CEP-1347 on the areas of the brain affected by Parkinson’s disease. The study recruited approximately 800 participants at 65 sites across the United States and Canada. Enrollment began in April 2002 and was completed in March 2004.
The Parkinson Study Group (PSG), in collaboration with Teva Clinical Research, Inc., conducted a study for patients with moderate to advanced Parkinson’s Disease called PRESTO (Parkinson’s Resagiline: Efficacy & Safety in the Treatment of “Off”). This 26-week study examined the safety, effectiveness and tolerability of an investigational drug in patients who do not experience full benefit from their L-dopa dosage. The study recruited about 450 subjects at 44 sites across the United States and Canada. Enrollment began in September 2000 and was completed in June 2002.
The PRIME (PRamipexole In Minority Persons with Parkinson’s Disease: Efficacy) study led by Caroline Tanner, MD, and Cynthia Comella, MD, and sponsored by Pharmacia & Upjohn, Inc. (Kalamazoo, MI) was a placebo-controlled, safety, efficacy and pharmacokinetic study of pramipexole in minority persons with moderate to advanced Parkinson’s disease who are receiving concomitant carbidopa/levodopa therapy. Enrollment of 144 subjects at 17 sites began in January 1997 and the final subject visit was completed in October 1998. This is the first trial in Parkinson’s disease designed to evaluate the influence of ethnicity on the safety, efficacy and pharmacokinetics of a therapeutic agent.
Diagnostic and Prognostic Biomarkers in Parkinson Disease Click here to view the trial record.
Parkinson’s Research: The Organized GENetics Initiative
The PSYCLOPS (PSYchosis and CLOzapine in Parkinson’S Disease) study led by Joseph Friedman, MD, and Christopher Goetz, MD, which examined the effects of the non-neuroleptic, antipsychotic clozapine on dopaminergic-induced psychosis in PD patients, was supported primarily by the FDA Orphan Drug Division. Enrollment of 60 subjects at six PSG sites began in April of 1995 and the final subject visit was completed in January 1997. This randomized, controlled clinical trial supported the findings of multiple open-label studies that low dose clozapine ameliorates psychosis without worsening parkinsonism. The results have been published in abstract form and a full report was in the March 1999 issue of the New England Journal of Medicine, volume 340, pg 757-763.
QE2 (Coenzyme Q10 Evaluation-2) was a randomized, double-blind, parallel group 16-month study, designed to compare three dosages of coenzyme Q10 (ubiquinone) and placebo in patients who have early PD. Ten PSG sites were selected to enroll 80 subjects. The goals of the study were to: (1) assess a clinical trial design devised to efficiently evaluate the maximally tolerated dose and efficacy of potential protective therapies for PD; (2) extend our previous studies of the safety and tolerability of high doses of coenzyme Q10; and (3) evaluate the ability of coenzyme Q10 to affect the clinical progression of PD and platelet mitochondrial function. Enrollment of 80 subjects was completed in February of 2000.
(Effects of Coenzyme Q10 in Parkinson Disease) Click here to view the trial record.
March 24, 2014 The primary manuscript for QE3 was accepted and has been published in JAMA Neurology. The abstract and manuscript can be viewed here .
July 27, 2012 The QE3 study was presented at the 16th International Congress of Parkinson’s Disease and Movement Disorders Meeting in Dublin, Ireland in June 2012. An abstract, or a short summary of study results, was presented at the meeting and a copy of the material is available here .
May 27, 2011 The NINDS has stopped the QE3 Phase III study of Coenzyme Q10 for treatment of early Parkinson’s disease acting on the recommendation of the study’s Data Safety Monitoring Board (DSMB).
Quality-of-Life Instrument/Economic Outcomes (PDQUALIF)
Parkinson’s Disease QUAlity of LIFe (PDQUALIF) was a multi-center study to develop and test a quality-of-life instrument specific for Parkinson’s disease. Under the direction of Mickie Welsh, RN, DNS, this study employed a cross-sectional design of individuals in all stages of Parkinson’s disease in an effort to establish the reliability and validity of the PDQUALIF. There were a total of 233 patients enrolled at the participating 13 PSG sites. Analysis compared the PDQUALIF to the SF36 and SIP quality-of-life instruments. An abstract of the preliminary results from Phase II testing was presented at the 1997 PSG/Movement Disorders Society (MDS) Symposia and published in Movement Disorders. In the CALM-PD and TEMPO trials, a modified PDQUALIF scale was used.
The RAMP (Remacemide As Monotherapy in Parkinson’s Disease) study, led by Ira Shoulson, MD, and J. Timothy Greenamyre, MD, PhD, and sponsored by Astra Pharmaceuticals was the first placebo-controlled study to evaluate the safety, tolerability and efficacy of dosages of remacemide as monotherapy in patients with early Parkinson’s disease. Enrollment of 200 subjects at 21 PSG sites began in March 1997 and was completed in April 1998.
The Parkinson Study Group (PSG), under the sponsorship of Teva Clinical Research, conduced a study for advanced Parkinson’s disease patients with motor complications (“on-off” effects) called RAPID (Rapid-Acting ParkInson’s Drug). This 20-24 week study of TV-1203/Carbidopa dispersible tablets, a novel investigational variation of levodopa, examined the efficacy, safety, and tolerability of TV-1203/Carbidopa dispersible tablets in treating advanced Parkinson disease patients who have motor fluctuations while being treated with chronic levodopa/carbidopa therapy. Teva Clinical Research, based in North Wales, PA is the U.S. affiliate of Teva Pharmaceutical Industries, LTD, Israel, an international pharmaceutical company headquartered in Israel. This study enrolled approximately 300 patients at 41 sites across the United States and Canada and completed enrollment in June 2002.
REAL (REmacemide as an Adjunct to Levodopa), led by Ira Shoulson, MD, and John Penney, MD, and sponsored by Astra Pharmaceuticals, was the first placebo-controlled study to evaluate the safety, tolerability and efficacy of remacemide in levodopa-treated patients with Parkinson’s disease who have motor fluctuations. Enrollment of 279 subjects at 29 PSG sites began in August 1997 and was completed in June 1998.
Follow-up of the 320 subjects in the ROADS (RO 19-6327 Assessment and Dose Finding Study) controlled trial of the MAO-B inhibitor lazabemide, led by Ira Shoulson, MD, and Karl Kieburtz, MD, was completed in 1994 and analysis was completed in 1995. Like deprenyl, lazabemide extended the time before emerging disability required the initiation of levodopa therapy in patients with early Parkinson’s disease. An abstract of the preliminary results of this 18-site investigation of lazabemide in untreated PD patients was presented in May 1995 at the annual meeting of the American Academy of Neurology. A full report was published in Annals of Neurology.
The SEESAW (Safety and Efficacy of Entacapone Study Assessing Wearing-off) controlled trial, led by Ira Shoulson, MD, and Stanley Fahn, MD, and sponsored by Orion-Farmos, Inc. (Espoo, Finland), was initiated in March 1994 to examine the impact of entacapone, a COMT inhibitor, in levodopa-treated PD patients with motor fluctuations. Enrollment of 205 subjects at 18 PSG sites was completed in December 1994, and follow-up was completed in June 1995. A summary of the results of the study was presented at the Fourth International Congress of Movement Disorders meeting in Vienna, Austria, June 1996 (published in Movement Disorders) and the 10th PSG/MDS Symposia in Miami, October 1996 (published in Movement Disorders). A full report of the SEESAW trial was published in Annals of Neurology.
A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study of the Safety, Pharmacokinetics, and Pharmacodynamics of BIIB054 in Subjects with Parkinson’s Disease
This study is now closed for participation recruitment.
The Parkinson Study Group (PSG) conducted the North American arm of this global study, under the direction of Andrew Siderowf, MD, a Phase 2a, randomized, double-blind, placebo-controlled trial to to evaluate the dose-related safety of BIIB054, to evaluate the pharmacodynamic effects of BIIB054 on the integrity of nigrostriatal dopaminergic nerve terminals, to assess the pharmacokinetic (PK) profile of BIIB054 and to evaluate the immunogenicity of BIIB054 in subjects with Parkinson’s disease. The trial was funded by Biogen and registered on clinicaltrials.gov (NCT03318523).
SPectroscopy IN Diagnosis of PD. Click here to view the trial record.
The PSG study, led by Karl Kieburtz, MD, and John Nutt, MD, and sponsored by Astra Pharmaceuticals, conducted the study SPIRAL (Study of Pharmacokinetic Interactions Between Remacemide And Levodopa), which was the first study to evaluate whether remacemide, a glutamate receptor antagonist, exerts an effect on circulating plasma levodopa concentrations in patients with Parkinson’s disease. Enrollment of 16 subjects at four sites began in February 1997 and was completed in April 1997. A report has been submitted for publication.
START-LE (Short Term Assessment of RO 19-6327 Tolerability in Levodopa Exposed Patients) was the second of the PSG’s trials investigating lazabemide. In this trial, sponsored by Hoffmann-La Roche and led by Ira Shoulson, MD, and Stanley Fahn, MD, 137 subjects being treated with levodopa for their Parkinson’s disease were enrolled at 14 sites from March 1991 to January 1992. This eight-week study demonstrated the overall safety and tolerability of lazabemide in subjects taking levodopa. The primary report of this study was published in Archives of Neurology.
Lazabemide (RO 19-6327) is a short-acting, reversible, highly selective inhibitor of monoamine oxidase type B which, unlike deprenyl, is not metabolized to active compounds. The PSG, under the sponsorship of Hoffmann-La Roche, Inc. (Nutley, NJ), and led by Ira Shoulson, MD, and Stanley Fahn, MD, undertook the first of its three trials of lazabemide in the study START-UP (Short Term Assessment of RO 19-6327 Tolerability in Untreated Parkinson’s Disease) from November 1990 to September 1991; 201 subjects with early, untreated PD were enrolled at 14 sites. The overall safety and benefits of lazabemide observed in this eight-week trial justified further long-term investigation of the drug. The primary report of the study was published in Annals of Neurology.
Phase II Safety, Tolerability, and Dose Selection Study of Isradipine as a Potential Disease-Modifying Intervention in Early Parkinson’s Disease (STEADY-PD) was undertaken in subjects with early PD not requiring dopaminergic therapy (dopamine agonists or levodopa) randomized 1:1:1:1 to 5, 10, or 20 mg of isradipine CR or matching placebo daily. The primary outcome was tolerability defined as no more than a 30% difference in the proportion of patients completing the study on the originally assigned dosage between an active and placebo group. If more than one isradipine dosage was tolerable, then a 3-point difference in total Unified Parkinson’s Disease Rating Scale (UPDRS) change between baseline and week 52 (or time to sufficient disability to require dopaminergic therapy) was taken as a criterion for selection of the most desirable dosage for future study. STEADY-PD enrolled 99 subjects. The tolerability of isradipine was dose dependent: placebo, 25 of 26 patients (96%); 5 mg, 19 of 23 patients (83%); 10 mg 19 of 26 patients (73%); and 20 mg 9 of 24 patients (37%). There was no difference in change in UPDRS among dosages. The most common adverse events were peripheral edema (30) and dizziness (24). Isradipine 10 mg daily was the maximal tolerable dosage in this study of early PD. A large placebo-controlled trial will be necessary and is planned to assess efficacy of isradipine 10 mg daily to slow progression of PD disability. *([Click here to download] the complete abstract.)
The Parkinson Study Group (PSG), under the direction of Tanya Simuni, MD (Northwestern University), and Robert G. Holloway, MD, MPH (University of Rochester), conducted a multi-center, randomized, double-blind, placebo-controlled study of isradipine in individuals with early Parkinson disease (PD) called STEADY-PD III: Efficacy of Isradipine in early Parkinson Disease. The purpose of STEADY-PD III was to assess the potential effect of isradipine on slowing the progression of PD. To view the results of this study, click here.
The STEP-UP (Safety, Tolerability and Efficacy of Pramipexole in Untreated Parkinsonism) controlled trial, led by Ira Shoulson, MD, and Stanley Fahn, MD, and sponsored by Pharmacia & Upjohn, Inc., was initiated in March 1994 to examine multiple dosages of the dopamine agonist pramipexole in early PD. Active follow-up of the 264 enrolled subjects at 20 PSG sites was completed in December 1994. An abstract summarizing the preliminary results of this trial was presented at the PSG/MDS Symposia in Washington, DC, October 1995, and published in Movement Disorders. A full report of the STEP-UP trial was published in the July 9, 1997 issue of the Journal of the American Medical Association.
Safety and Ability to Elevate URate in Early Parkinson Disease. Click here to view the trial record.
TEMPO (Rasagiline Mesylate [TVP-1012] inEarly Monotherapy for PD Outpatients), led by Ira Shoulson, MD, and Stanley Fahn, MD, is a placebo-controlled multi-center trial, sponsored by Teva Pharmaceutical Industries, Ltd. – Israel and Teva Pharmaceuticals, USA, examining the effects of two dosages of rasagiline in patients with early Parkinson’s disease. Rasagiline is a novel MAO-B inhibitor. Enrollment of approximately 400 patients at 27 PSG sites began in November 1997 and was completed in April of 1999. The results of the TEMPO study were published in Archives of Neurology on December 18, 2002.
The TEST-PD/RETEST-PD (Tolerability and Efficacy of SIB-1508Y Therapy in PD), led by Ira Shoulson, MD and John Growdon, MD, and sponsored by SIBIA Neurosciences, Inc. (La Jolla, CA), is the first placebo-controlled study to evaluate the safety, tolerability and efficacy of dosages of SIB-1508Y in patients with Parkinson’s disease who are requiring, but not receiving, dopaminergic therapy. SIB-1508Y is a nicotinic acetylcholine receptor agonist which produces motor and cognitive benefits in animal models of Parkinson’s disease. Enrollment of 32 subjects at ten sites for the initial phase of the study (TEST-PD, higher dosage groups) began in January 1998 and was completed in May, 1998. Enrollment of 45 subjects for the second phase (RETEST-PD, lower dosage groups) began in July 1998 and was completed in April 1999. The data are currently being analyzed.