Levetiracetam in the Preventive Treatment of Transformed Migraine: A Prospective, Open-Label, Pilot Study

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VOLUME 66, NUMBER 3, MAY/JUNE 2005 Levetiracetam in the Preventive Treatment of Transformed Migraine: A Prospective, Open-Label, Pilot Study Alan M. Rapoport, MD1,2; Fred D. Sheftell, MD2,3; Stewart J. Tepper, MD2,4; and Marcelo E. Bigal, MD, PhD 2,s 7Department of Neurology, Columbia University College of Physicians and Surgeons, New York, New York; 2The New England Center for Headache, Stamford, Connecticut; 3Department of Psychiatry, New York Medical College, New York, New York; 4Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and 5Department of Neurology, Albert Einstein College of Medicine, Bronx, New York ABSTRACT Background: Most preventive agents used for transformed migraine (TM) have not been studied specifically for the treatment of this syndrome. Openlabel trials have demonstrated the effectiveness of levetiracetam in the treatment of refractory headaches. Objective: The aim of this study was to assess the effectiveness and tolerability of levetiracetam in the preventive treatment of refractory TM. Methods: This prospective, open-label, pilot study was conducted at The New England Center for Headache, Stamford, Connecticut. We included patients aged ~18 years with refractory TM according to the criteria proposed by Silberstein et al. All participants had failed on at least 1 but not more than 3 preventive drugs. Other preventive drugs were allowed if they had been received at a stable dose for >30 days. The dosage of the levetiracetam tablets ranged from 1000 to 3000 mg/d in 2 divided doses. The treatment phase lasted 3 months. The primary end point was headache frequency (expressed as the number of headache days per month), and the secondary end point was the frequency of moderate or severe headache (d/mo). Other end points were headache score, Migraine Disability Assessment (MIDAS) Questionnaire score, and Headache Impact Test (HIT-6) score. Statistical analyses were performed in the intent-totreat (ITT) population (patients who received at least 1 dose of study medication) using data subjected to the last-observation-carried-forward algorithm. We also conducted per-protocol (PP) analyses in patients who completed the study. Results: The ITT population consisted of 36 patients (26 women, 10 men; mean [SD] age, 46.5 [17.4] years). The mean headache frequency at baseline was 24.9 d/mo, and a significant reduction in headache frequency was obtained at 1, 2, and 3 months of treatment (19.4, 18.4, and 16.2 d/mo, respectively; all, P< 0.001 Accepted for publication March 18, 2005. Reproduction in whole or part is not permitted. doi:l 0.1016/j.curtheres.2005.06.006 0011-393X/05/$19.00 212 Copyright 2005 Excerpta Medica, Inc.

A.M. Rapoport et al vs baseline). At baseline, the mean number of moderate or severe headache days was 16.8 d/mo compared with 13.2, 11.9, and 9.7 d/mo at 1, 2, and 3 months, respectively (P = NS, <0.01, and <0.01, respectively). The mean MIDAS score was significantly reduced at 3 months compared with baseline (40.8 vs 62.8 d/mo; P = 0.01). The mean HIT-6 score was 59.4 at 3 months versus 63.4 at baseline (P < 0.01). In the PP population, the mean (SD) headache frequency was reduced from 26.1 (4.1) d/mo at baseline to 14.3 (4.8) d/mo at the end of the study (P < 0.001). The mean (SD) headache score was reduced from 51.3 (17.1) at baseline to 34.0 (22.0) at 3 months (P < 0.016). Conclusion: The results of this study in patients with TM support the role of levetiracetam in the preventive treatment of refractory TM. (Curr Ther Res Clin Exp. 2005;66:212-221) Copyright 2005 Excerpta Medica, Inc. Key words: levetiracetam, transformed migraine, chronic daily headache, preventive treatment, prevention. INTRODUCTION Transformed migraine (TM) is the most frequent subtype of chronic daily headache (CDH) seen in headache clinics. 1-3 Most patients with TM have a history of episodic migraine, reporting a process of transformation characterized by an increase in headache frequency over months to years, with the associated symptoms becoming less severe. Patients then develop a pattern of daily or neardaily headache, the phenomenology of which may resemble that of chronic tension-type headache, with a few attacks of full-blown migraine superimposed. 4 The pharmacologic treatment of TM poses a challenge to the physician. Most preventive agents used for TM have not been examined specifically for the treatment of this syndrome; they are used empirically based on their efficacy in the treatment of episodic migraine. 5 Neuromodulators are frequently used in the preventive treatment of migraine 5,6 and TM. 6,7 Multiple threads of research over the past 15 years have led to the concept that migraine is generated from a hyperexcitable brain. 8,9 Although we do not know whether migraine is generated in the cortex or brainstem, one possible scenario includes a cascade of events beginning with either brainstem or cortical activation followed by the other, leading to activation of ascending and descending pathways, with initiation of perimeningeal vasodilatation and neurogenic inflammation, and, ultimately, central sensitization, l,n From a theoretical perspective, the efficacy of neuromodulators in the preventive treatment of migraine may correlate with their neuronal stabilization properties. Levetiracetam is an anticonvulsant medication with an incompletely understood mechanism of action. 12 Its use has been approved in the United States and Europe for the treatment of epilepsy. Case series have suggested the effectiveness of levetiracetam in the treatment of refractory headache. 13,14 However, levetiracetam has not been specifically studied in the treatment of TM. Therefore, the aim of this study was to prospectively assess the effec- 213

CURRENT THERAPEUTIC RESEARCH tiveness and tolerability of levetiracetam in the preventive treatment of refractory TM. PATIENTS AND METHODS This prospective, open-label, pilot study was conducted at The New England Center for Headache, Stamford, Connecticut. Inclusion and exclusion criteria were as follows: (1) age _18 years; (2) a diagnosis of TM with or without medication overuse, according to the criteria proposed by Silberstein et a14; (3) previous failure on at least 1 but no more than 3 preventive drugs; (4) previous failure with no more than 1 antiepileptic drug used in therapeutic migraine doses for an adequate time period; (5) a stable dose of preventive medication for at least 1 month (other preventive drugs were allowed if a stable dose had been used for >30 days); and (6) no use of other antiepileptic drugs within the previous 30 days. There was a 1-month baseline observation period, and information was collected prospectively using headache calendars. After the baseline period, levetiracetam was started at 250 mg hs and increased by 250 mg every 5 days up to a dose of 1000 mg hs. After the dose adjustment (second month), the dose could be increased further over the next 2 weeks up to a total dosage of 3000 mg/d in 2 divided doses. The treatment phase lasted 3 months (1 month of adjustment and 2 months of stable dosing). Headache information was collected using headache calendars. Disability was assessed using the Migraine Disability Assessment (MIDAS) Questionnaire 15 (scale: 0-5 = grade I [minimal or infrequent disability]; 6-10 = grade II [mild or infrequent disability]; 11-20 = grade III [moderate disability]; and _ 21 = grade IV [severe disability]) and the Headache Impact Test (HIT-6) version 1.116 (scale: 38-49 = little or no impact on patient's life; 50-55 = some impact; 56-59 = substantial impact; 60-78 = very severe impact). The primary end point was headache frequency (ie, the number of headache days per month), and the secondary end point was the number of days with moderate or severe headache (d/mo). Other end points included headache score (frequency multiplied by severity assessed on a 4-point scale [0 = no pain to 3 = severe pain]), and MIDAS 15 and HIT-616 scores. Patients were instructed to return for monthly follow-up. At all visits, patients were specifically asked whether they had experienced any unexpected symptoms or signs. Adverse events (AEs) were defined as any untoward medical occurrences during the study, regardless of causal relationship with the treatment. These included any occurrence that was new in onset or aggravated in severity or frequency from the baseline condition. Statistical Analysis Statistical analyses were performed in the intent-to-treat (ITT) population (patients who received at least 1 dose of study medication) using data subjected to the last-observation-carried-forward algorithm. We also conducted per- 214

A.M. Rapoport et al protocol analyses in patients who completed the study. To compare data from several time points, we used 1-way analysis of variance after normality testing. Data were compared with the paired t test, assuming a 5% 2-tailed significance level. Our study was powered at 80% to detect a 30% difference using matching comparisons at the 5% level. This study protocol received institutional review board approval prior to the initiation of the study. All participants signed an institutional review boardapproved informed-consent form. RESULTS The ITT population consisted of 36 patients (26 women, 10 men; mean [SD] age, 46.5 [17.4] years) (Table I). Twenty patients (55.6%) completed the study; 8 (22.2%) withdrew because of AEs, 5 (13.9%) withdrew consent, and 3 (8.3%) were lost to follow-up (Figure 1). Table I. Baseline demographic and clinical characteristics of the study population (N = 36). Characteristic Value Age, mean (SD), y 46.5 (1 7.4) Sex, no. (%) Female 26 (72.2) Male 10 (27.8) Race, no. (%)* White 25 (69.4) Black 7 (19.4) Other t 4 (11.2) Preventive medication, no. (%) None 11 (30.6) Propranolol 11 (30.6) Amitriptyline 10 (27.8) Nortriptyline 9 (25.0) Verapamil 3 (8.3) Candesartan 3 (8.3) Nadolol 2 (5.6) Other ~ 5 (13.9) *Percentages do not total 100 due to rounding. tlncludes Hispanic and not specified. ~lncludes magnesium, riboflavin, coenzyme Q10, flunarizine, and venlafaxine. 215

CURRENT THERAPEUTIC RESEARCH Figure 1. Study design. Signed the consent form (39 patients) l Received at least 1 dose of study medication (36 patients) 1 Completed the study (20 patients) IJ Withdrew because of adverse effects (8 patients) Withdrew consent (5 patients) Lost to follow-up (3 patients) Effectiveness Intent.to- Treat Population Eleven patients (30.6%) were not using other preventive drugs when enrolled, 10 (27.8%) were using 1 preventive drug, and 15 (41.7%) were using 2 or 3 preventive drugs. Among those who completed the titration phase (33 patients [91.7%]), the median dose was 1250 mg (range, 750-2000 mg). The final doses were 750 mg in 1 patient (3.0%), 1000 mg in 11 (33.3%), 1250 mg in 12 (36.4%), 1500 mg in 7 (21.2%), and 1750 mg and 2000 mg in 1 patient each (3.0%). At baseline, the mean headache frequency was 24.9 d/mo. A significant reduction in headache frequency was observed at 1 month (19.4 d/mo), 2 months (18.4 d/mo), and 3 months (16.2 d/mo) (all, P< 0.001 vs baseline) (Figure 2). The mean number of moderate or severe headache days at baseline (16.8 d/mo) was statistically similar compared with 1 month (13.2 d/mo). However, frequencies of moderate or severe headache were significantly lower at 2 and 3 months (11.9 and 9.7 d/mo, respectively; both, P < 0.01 vs baseline) (Figure 3). The mean MIDAS 15 score was significantly reduced at 3 months compared with baseline (40.8 vs 62.8; P = 0.01). The mean HIT-616 score was 59.4 at 3 months compared with 63.4 at baseline (P < 0.01). Per-Protocol Population In regard to participants completing this study (20 patients [55.6%]), we correlated end points at baseline and completion (Table II). Mean (SD) headache frequency was reduced from 26.1 (4.1) d/mo at baseline to 14.3 (4.8) d/mo at the end of the study (P < 0.001). We also found significant differences in the number of moderate or severe headache days per month between baseline and study completion (18.0 [8.3] vs 9.7 [7.8] d/mo; P< 0.006), headache score (51.3 [17.1] 216

A.M. Rapoport et al. o E e- o" u. 26 24 22 20 18 16 14 12 10 8 6 4 2 0 ~asellne I Mo 2 Mo 3 Mo Figure 2. Frequency of headache before (baseline), during, and after 3 months of preventive treatment with levetiracetam in patients with transformed migraine (N = 36). *P < 0.001 versus baseline. o E "o v e- o" LL 24 22 20 18 16 14 12 10 8 6 4 2 0 I 1 - - T ~asellne I Mo 2 Mo 3 Mo Figure 3. Frequency of moderate or severe headache before (baseline), during, and after 3 months of preventive treatment with levetiracetam in patients with transformed migraine (N -- 36). *P < 0.01 versus baseline. 217

CURRENT THERAPEUTIC RESEARCH Table II. End points as assessed in the per-protocol analysis (n = 20). Data are expressed as mean (SD). End Point Baseline 3 Months P Frequency of headache, d/too 26.1 (4.1) 14.3 (4.8) <0.001 Frequency of moderate or severe headache, d/mo 18.0 (8.3) 9.7 (7.8) <0.006 Headache score* 51.3 (17.1) 34.0 (22.0) <0.016 MIDAS Questionnaire is score t 76.7 (32.1) 29.3 (23.0) 0.01 HIT-616 score :~ 64.8 (5.9) 57.7 (7.9) <0.006 MIDAS = Migraine Disability Assessment; HIT-6 = Headache Impact Test. *Calculated as frequency multiplied by severity as assessed on a 4-point scale (0 = no pain to 3 = severe). tscale: 0-5 = grade I (minimal or infrequent disability); 6-10 = grade II (mild or infrequent disability); 11-20 = grade Ill (moderate disability); and _>21 = grade IV (severe disability). ~Scale: 38-49 -- little or no impact on patient's life; 50-55 = some impact; 56-59 = substantial impact; 60-78 = very severe impact. vs 34.0 [22.0]; P< 0.016), MIDAS 15 score (76.7 [32.1] vs 29.3 [23.0]; P-- 0.01), and HIT-6 z6 score (64.8 [5.9] vs 57.7 [7.9]; P < 0.006). Tolerability AEs were reported by 18 patients (50.0%); 8 patients (22.2%) withdrew from the study because of poor tolerability (somnolence, 2 patients [5.6%]; lack of concentration, 2 [5.6%]; and chest tightness, constipation, anorgasmia, and ankle edema, 1 [2.8%] each). The most common AEs were somnolence and asthenia (10 patients [27.8%] each) and anxiety (5 patients [13.9%]). Weight gain (4 patients [11.1%]) and depression and emotional instability (2 patients [5.6%] each) also occurred. The following AEs were also reported by 1 patient (2.8%) each: anorgasmia, ankle edema, constipation, and chest tightness. DISCUSSION TM is the most frequently seen headache syndrome at headache centers, z,3,17,18 Previous studies show that the transformation process in patients with migraine is associated with increases in not only frequency but also associated disability. 19 Based on a literature search (key terms: refractory headache, treatment, and transformed migraine; years, 1980-2005), most studies addressing the treatment of refractory headaches have focused on CDH overall, 14,2 while few studies have addressed the preventive treatment of TM as a distinctive subgroup of CDH. Most reports of TM are anecdotal. 21,22 An open-label trial assessing the possible benefits of sodium valproate in patients with CDH that was refractory to multiple standard treatments found that 50% of patients had some kind of response and 10% discontinued medication due to AEs. 2 Shuaib et a123 treated 37 patients with refractory 218

A.M. Rapoport et al migraine or CDH with topiramate in an open-label study. Thirty percent had an excellent result and 30% had a good result. Recent studies have assessed the prevention of CDH with botulinum toxin type A, 22 zonisamide, 24 tizanidine (in a double-blind study), 25 and quetiapine. 25 The reductions in headache frequency were 30% at 1 month in patients treated with tizanidine 25 and 37% at 3 months in patients treated with zonisamide. 24 A retrospective study found a reduction of 36.5% in headache frequency at 2 months in patients using daily naratriptan. 26 We found that levetiracetam may be an effective drug in the prevention of TM. For the ITT population, headache frequency decreased 34.9%, the number of days with moderate or severe headache pain decreased by 42.2%, and disability scores decreased significantly (both, P _< 0.01). In those who completed the study, headache frequency was reduced by 45.2%, and the number of moderate or severe headache days per month was reduced by 46.1%. The treatment of refractory headache, including TM, is quite often unsuccessful. 1,2,5 Although we believe that ITT analyses provide a more balanced statistical approach, subanalyses of patients who completed the study can be of interest. For refractory headache, a drug that provides significant relief to even a small fraction of patients is useful. In a recent study, Saper et a127 found that daily opioid therapy for refractory headache was useful in just 25% of patients in the long term. However, considering the degree of refractoriness of the sample, they concluded that this modality of treatment might provide relief to some selected patients with TM. We found that levetiracetam was effective overall, and subanalyses of the completers strongly reinforced the results of the ITT analysis. We verified a high rate of AEs in our study population. AEs were reported by 50.0% of patients and led to a withdrawal rate of 22.2%. Most of those who withdrew from the study were using preventive medications in addition to levetiracetam, which may have increased their risk for AEs and/or drug-drug interactions. For most neuromodulators, polypharmacy is associated with a higher frequency of AEs. 28 Therefore, drug-drug interactions may at least partially explain our findings. Second, several trials have reported that the AE rates are higher in TM compared with migraine. 13,21,22 Double-blind trials investigating levetiracetam used as monotherapy are necessary to fully assess the tolerability of this drug. Our results support previous findings. Drake et a113 investigated levetiracetam use in the prevention of refractory headache, including CDH. Treatment with concomitant medications was continued. A clinical benefit was noted after 1 month of treatment. Ten patients (16.1%) discontinued the drug because of AEs. A second study investigated the use of levetiracetam in patients with CDH whose treatment had previously failed with 2 to 4 medications; 46.7% of the patients reported a reduction in headache frequency of at least 50%, and 26.7% discontinued treatment with the drug due to AEs. 14 While these studies investigated levetiracetam in the prevention of any type of refractory headache, we included only patients with TM in our study. Caution should be used when analyzing our results for several reasons. First, although this pilot study was prospective, it was not placebo controlled. 219

CURRENT THERAPEUTIC RESEARCH Neither the patients nor the health care providers were blinded to treatment. Second, we included patients with TM with and without medication overuse; patients overusing medication had previously failed detoxification protocols. None of the patients discontinued medication overuse during our study. Because studies show that preventive medication is often ineffective in patients overusing acute care medication, 5,14,17,18,21 we may have underestimated the benefits of levetiracetam by including overusers. However, most of our patients (73.3%) were not overusing acute care medication. Additionally, some patients were using several different preventive medications. Finally, not all of the patients received the same dose of levetiracetam, which may have influenced some comparisons regarding efficacy and tolerability. CONCLUSIONS The results of this pilot study in patients with TM suggest that levetiracetam is a promising drug for the preventive treatment of TM, although it has neither been submitted to nor approved by the US Food and Drug Administration for this use. Because TM evolves from episodic migraine, our data suggest that levetiracetam may have a role in the preventive treatment of frequent episodic migraine. A necessary future step forward is to conduct a double-blind, placebocontrolled study of levetiracetam in the treatment of TM. ACKNOWLEDGMENT This study was financially supported by a grant from UCB Pharma Inc., Smyrna, Georgia. REFERENCES 1. Mathew NT. Medication misuse headache. Cephalalgia. 1998;18(Suppl 21):34-36. 2. Solomon S, Lipton RB, Newman LC. Evaluation of chronic daily headache--comparison to criteria for chronic tension-type headache. Cephalalgia. 1992;12:365-368. 3. Bigal ME, Sheftell FD, Rapoport AM, et al. Chronic daily headache in a tertiary care population: Correlation between the International Headache Society diagnostic criteria and proposed revisions of criteria for chronic daily headache. Cephalalgia. 2002;22: 432-438. 4. Silberstein SD, Lipton RB, Sliwinski M. Classification of daily and near-daily headaches: Field trial of revised IHS criteria. Neurology. 1996;47:871-875. 5. Spierings EL. Treatment and outcome of chronic daily headache. Otolaryngol Clin North Am. 2003;36:1109-1117. 6. Freitag FG. Divalproex sodium extended-release for the prophylaxis of migraine headache. Expert Opin Pharmacother. 2003;4:1573-1578. 7. Brandes JL, Saper JR, Diamond M, et al, for the MIGR-002 Study Group. Topiramate for migraine prevention: A randomized controlled trial. JAMA. 2004;291:965-973. 8. Welch KM, D'Andrea G, Tepley N, et al. The concept of migraine as a state of central neuronal hyperexcitability. Neurol Clin. 1990;8:817-828. 9. Goadsby PJ. Migraine, aura, and cortical spreading depression: Why are we still talking about it? Ann Neurol. 2001;49:4-6. 220

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