[Long-term efficacy and safety of divozilimab during 2-year treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-4/MIRANTIBUS]. / Effektivnost' i bezopasnost' dvukhletnei terapii divozilimabom u patsientov s rasseyannym sklerozom v ramkakh randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-4/MIRANTIBUS.

OBJECTIVE: To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg every 24 weeks during 100 weeks for the treatment of patients with multiple sclerosis (MS), including relapsing-remitting multiple sclerosis (RRMS) and secondary progressive MS (SPMS) with relapses. MATERIAL AND METHODS: The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS (NCT05385744) included 338 adult patients with MS distributed in a 1:1 ratio into two groups: DIV 500 mg and teriflunomide (TRF) 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks, then entered an additional period from weeks 49 to 100, which included three cycles of therapy. The efficacy was assessed based on the results of brain MRI and registration of data on relapses. RESULTS: 308 subjects completed 5 therapy cycles according to the study protocol. An analysis of the effectiveness of DIV therapy over 2 years showed a persistent suppression of MRI and clinical activity of the disease in comparison with TRF, which was confirmed by all the studied MRI indicators (including CUA; total number of gadolinium-enhancing (GdE) lesions on T1-weighted scans ; number of new or enlarged lesions on T2-weighted scans; lesions volume change on T2-weighted scans; change in the volume of hypointense lesions on T1-weighted scans). The use of DIV was associated with a statistically significant decrease in ARR compared to TRF (p=0.0001). The ARR in the DIV group was 0.057, in the TRF group - 0.164 with 95% confidential interval for the frequency ratio [0.202; 0.593]. The incidence of GdE lesions on T1-weighted scans in the DIV group was significantly lower than in the TRF group. The average number of such lesions was 0.0±0.08 and 1.0±4.46 in the DIV and TRF groups, respectively (p<0.0001). Progression of EDSS was detected in 18 (10.7%) and 36 (21.3%) patients in the DIV and TRF groups, respectively (p=0.0075). The proportion of patients with relapses was 11.2% (n=19) in the DIV group and 23.1% (n=39) in the TRF group (p=0.0039). In the subpopulation of patients with SPMS, no cases of increase in EDSS were detected, and not a single case of exacerbation was recorded over 2 years of using DIV. Also, DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and laboratory abnormalities, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences. CONCLUSION: The results of the BCD-132-4/MIRANTIBUS CT indicate a high sustained efficacy and safety of long-term use of DIV in comparison with TRF during 2 years of therapy.

[POEMS-syndrome]. / POEMS-sindrom.

POEMS-syndrome (polyneuropathy - P, organomegaly - O, endocrinopathy - E, M-protein - M, skin changes - S) is a paraneoplastic syndrome caused by underlying dyscrasia of plasma cells. The main criteria of the syndrome are polyradiculoneuropathy, clonal proliferation of plasma cells, sclerotic bone lesions, elevated levels of vascular endothelial growth factor and the presence of Castleman disease. Additional signs include organomegaly, endocrinopathy, characteristic skin changes, edema of the optic disc, extravascular volume overload (edema) and thrombocytosis. The diagnosis is often made late, because the syndrome is rare and is often mistaken by specialists for other neurological disorders, most often for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We present two cases of POEMS-syndrome. The description is based on the principle of differential diagnosis with a number of similar neurological disorders. The goal facing the neurologist is to carry out the most complete diagnostic measures for early diagnosis, which further determines timely therapeutic tactics. Hematologists are engaged in specific therapy of POEMS-syndrome. A brief description of possible therapeutic options is presented. On the example of these cases, we demonstrate possible variants of the therapeutic response based on the developed system of risk stratification of patients with POEMS-syndrome.

[Efficacy and safety of antiCD20 monoclonal antibody divozilimab during 48-week treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-4/MIRANTIBUS]. / Effektivnost' i bezopasnost' 48 nedel'nogo primeneniya monoklonal'nogo antitela protiv CD20 divozilimaba u patsientov s rasseyannym sklerozom: rezul'taty randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-4/MIRANTIBUS.

OBJECTIVE: To evaluate the efficacy and safety of the anti-CD20 monoclonal antibody divozilimab (DIV) used as an intravenous infusion at a dose of 500 mg for the treatment of patients with relapsing-remitting multiple sclerosis (RRMS) in comparison with the teriflunomide (TRF). The study of the efficacy and safety of the use of the drug DIV was carried out for 48 weeks of therapy. MATERIAL AND METHODS: The multicenter, randomized, double-blind and double-masked phase III clinical trial (CT) BCD-132-4/MIRANTIBUS included 338 adult patients with RRMS distributed in a 1:1 ratio into two groups: DIV 500 mg and TRF 14 mg. After screening, subjects were included in the main CT period, which consisted of two cycles of therapy over 48 weeks. The primary end point was «Mean annualized relapse rate 48 weeks after the last patient is randomized in the study¼. RESULTS: 321 subjects completed 48 weeks of therapy according to the study protocol. The analysis of the of efficacy data for the primary endpoint successively proved the hypothesis of superiority of the test drug DIV at a dose of 500 mg over the reference drug TRF. A rapid suppression of acute disease activity according to the brain MRI and clinical manifestations of the disease was shown after the first infusion of DIV in patients with RRMS. Thus, after 48 weeks of therapy in patients treated with DIV, there were no T1 gadolinium-enhancing lesions, while in the TRF group such lesions were observed in 20.7% (35/169) of subjects. Evaluation of the CUA per scan showed that the mean values for the estimated period were statistically significantly lower in the DIV drug group compared to the TRF group: the ratio of the adjusted per scan rates (DIV/TRF) was 0.125 [95% CI: 0.089; 0.177]. Over the 48 weeks of therapy, the proportion of subjects with relapses was 9.5% (n=16/169) in the DIV group and 19.5% (33/169) in the TRF group (p=0.0086). DIV has shown a favorable safety profile. Among the adverse reactions (AR), infusion reactions and deviations of laboratory data, such as a decrease in the number of leukocytes, neutrophils, and lymphocytes, were most often recorded. Identified AR were expected, had mild to moderate severity, and resolved without any negative consequences. CONCLUSION: The results of the clinical study indicate the high efficacy and safety of DIV in comparison with TRF.

[Efficacy and safety of divozilimab during 24-week treatment of multiple sclerosis patients in randomized double-blind placebo-controlled clinical trial BCD-132-2]. / Effektivnost' i bezopasnost' 24 nedel' primeneniya divozilimaba sredi patsientov s rasseyannym sklerozom v ramkakh randomizirovannogo dvoinogo slepogo platsebo-kontroliruemogo klinicheskogo issledovaniya BCD-132-2.

OBJECTIVE: To find the optimal therapeutic dose of the anti-B cell mAb divozilimab (DIV) based on the efficacy and safety data of intravenous administration at a dose of 125 mg or 500 mg in patients with relapsing remitting multiple sclerosis (RRMS) compared to placebo (PBO) and teriflunomide (TRF). To study the efficacy and safety of DIV within 24 weeks of treatment. MATERIAL AND METHODS: A multicenter, randomized, double-blind and double-masked, placebo-controlled phase 2 clinical trial (CT) BCD-132-2 involved 271 adult patients with RRMS from 25 centres In Russia. Patients were randomly assigned (2:2:2:1) into 4 groups: TRF, DIV 125 mg, DIV 500 mg and PBO. After screening patients entered to the main period, which consisted of one cycle of therapy for 24 weeks. The primary endpoint was the total number of gadolinium-enhancing T1 lesions (Gd+) observed on brain MRI scans after 24 weeks (per scan - involves estimating the mean value of the score from all the MRI assessments performed for each participant in the study). RESULTS: 263 patients completed 24 weeks of treatment. Most of the patients in the DIV groups had no lesions on T1-weighted MRI after 24 weeks of treatment (94.44% on 125 mg and 93.06% on 500 mg). In the TRF and PBO groups the values were significantly lower: 68.06% and 56.36% respectively (both p<0.05). The proportions of relapse-free patients in the DIV groups were 93.06% and 97.22% (125 mg and 500 mg, respectively). As expected, DIV reduced the CD19+ B-cells. However, the repopulation rate of CD19+ B-cells in the 125 mg group was more pronounced (mainly due to the recovering pool of CD27-naive B-cells) compared to the 500 mg group. DIV showed a favorable safety profile at both doses. CONCLUSION: Thus, the assessment of 24 weeks treatment demonstrated that DIV is a highly effective, safe and convenient option for the treatment of RRMS patients, both naive and previously treated with disease modifying therapy. A dose of 500 mg is recommended for further efficacy and safety evaluation during phase 3 CT.

[Long-term Efficacy and Safety of Sampeginterferon-ß1a in the Treatment of Relapsing Remitting Multiple Sclerosis: a Randomized, Double-Blind Clinical Trial 104-Week Results]. / Dolgosrochnye dannye po effektivnosti i bezopasnosti preparata sampeginterferon-ß1a u patsientov s remittiruyushchim rasseyannym sklerozom: rezul'taty 104-nedel'nogo randomizirovannogo dvoinogo slepogo klinicheskogo issledovaniya.

OBJECTIVE: To assess the efficacy and safety of sampeginterferon-ß1a (samPEG-IFN-ß1a) 180 µg and 240 µg administered once every 2 weeks compared to placebo and low dose interferon beta-1a (LIB) 30 µg administered once weekly. MATERIAL AND METHODS: Patients with relapsing-remitting multiple sclerosis aged 18-60 years, with Expanded Disability Status Scale score ≤5.5 were randomized at a ratio of 2:2:2:1 to the following groups: samPEG-IFN-ß1a 180 µg, samPEG-IFN-ß1a 240 µg, LIB, placebo. After 20 weeks, the placebo group completed the study. After week 52, the final analysis was performed, which included the primary endpoint analysis, the LIB group patients completed their participation in the study. The patients in samPEG-IFN-ß1a groups continued to receive therapy with samPEG-IFN-ß1a 240 µg until week 100 inclusive. The results of the final analysis after 52 weeks have been previously published. The current article presents a long-term efficacy and safety of samPEG-IFN-ß1a after 104 weeks of the trial. RESULTS: The annualized relapse rate over the second year was 0.16 in the samPEG-IFN-ß1a 180 µg group and 0.09 in the samPEG-IFN-ß1a 240 µg group. By week 104, the proportion of relapse-free patients was 77.0% (87/113) and 83.3% (95/114) in the samPEG-IFN-ß1a 180 µg and 240 µg groups, respectively. There were no negative dynamics of MRI markers, neurological deficit parameters and cognitive functions by scales and tests. The safety profile of samPEG-IFN-ß1a was consistent with the known safety profile of IFN-ß therapy. CONCLUSION: Treatment with samPEG-IFN-ß1a is an effective and safe first-line therapy for relapsing-remitting multiple sclerosis patients.

[Long-term treatment for multiple sclerosis with interferon beta-1b. Outcomes of an open, retrospective, observational study]. / Dolgosrochnaya terapiya rasseyannogo skleroza interferonom beta-1b. Rezul'taty retrospektivnogo otkrytogo nablyudatel'nogo issledovaniya.

OBJECTIVE: To assess the outcomes of long-term treatment in multiple sclerosis (MS) patients with Infibeta (interferon beta-1b). MATERIAL AND METHODS: The article presents the results a real-world, multicenter, retrospective, observational study of treatment with interferon beta-1b. We enrolled 332 patients with MS who had been receiving Infibeta for at least 8 years. 60.2% of them had a relapsing-remitting MS (RRMS). 73.2% patients received only interferon beta-1b that was initial DMT. RESULTS: During the first year of the treatment, 66% of the patients reported no relapses regardless of the MS type. No relapses in the 8th year of treatment were observed in 86.9% of patients with RRMS and 77.7% with secondary progressive MS (SPMS). The median number of relapses during the whole follow-up period in RRMS patients was 1. The time to first relapse in the subgroup of patients who received interferon beta as the first treatment was longer compared to other treatment (median 4 and 2, respectively, p=0.0017). 42% of patients with RRMS remained progression-free during 8 years of follow-up. The flu-like syndrome was observed in 61.7% for the first year of treatment; in 36.3% it was periodically and was mild in 71.3%. CONCLUSION: The study outcomes confirm a high clinical response to the long-term treatment with Infibeta in patients with RRMS and SPMS and demonstrate that interferon beta-1b is one an optimal option for the initial treatment of patients with moderate disease activity.

[Efficacy and safety of sampeginterferon ß-1a in the treatment of relapsing remitting multiple sclerosis: results of 52 weeks of therapy in a randomized, double-blind clinical trial]. / Effektivnost' i bezopasnost' sampeginterferona ß-1a dlya lecheniya remittiruyushchego rasseyannogo skleroza: rezul'taty 52-nedel'nogo randomizirovannogo dvoinogo slepogo klinicheskogo issledovaniya.

OBJECTIVE: To evaluate the efficacy and safety of samPEG-IFN-ß1a 180 µg and 240 µg administered once every 2 weeks for the treatment of relapsing remitting multiple sclerosis (RRMS) compared to placebo and low dose interferon beta-1a (LIB) 30 µg administered once weekly. The primary endpoint after 52 weeks of therapy was the time to first relapse, the hypotheses of non-inferiority and superiority to LIB were tested. MATERIAL AND METHODS: This international, multicenter, double blind, comparative, placebo-controlled clinical study enrolled 399 patients with the diagnosis of RRMS, randomized in 4 groups: samPEG-IFN-ß1a180 µg (n=114), samPEG-IFN-ß1a 240 µg (n=114), LIB (n=114) and placebo (n=57). Placebo group patients participated in the study for 20 weeks. After 52 weeks of therapy and 4 weeks of follow-up, LIB group patients completed their participation in the study, patients from PEG-IFN-ß1a groups continued to receive therapy until week 100 inclusive. The article presents the results of an analysis conducted after the end of 52 weeks of a double-blind, comparative, randomized, placebo-controlled clinical trial. RESULTS: Final analysis of the efficacy and safety was performed after 52 weeks of study. Main statistical hypothesis testing proved that both doses of samPEG-IFN-ß1a were equally effective when compared to LIB by the primary endpoint - «Time to first relapse¼. Due to detection of statistically significant differences in the primary endpoint between the study drug and the reference drug, indicating a greater efficacy of the study drug, an additional testing was carried out and the hypothesis of superiority of samPEG-IFN-ß1a at a dose of 240 µg over the reference LIB was proved. Evaluation of the dynamics of certain key parameters of magnetic resonance imaging (MRI) of the brain and clinical outcomes demonstrated a positive effect of samPEG-IFN-ß1a therapy in the form of decreased activity of the demyelinating process in the brain and reduce the number of relapses. The proportion of patients without new T2 lesions after 52 weeks was 87.6% and 90.4% in 180 µg and 240 µg samPEG-IFN-ß1a groups, versus 72.6% in the LIB group (p=0.0199 and p=0.0033). No progression of multiple sclerosis was shown based on EDSS scale evaluation. During the study, the most common adverse reactions were flu-like symptoms and injection site reactions. CONCLUSION: The new drug samPEG-IFN-ß1a is an effective and safe agent for relapsing remitting multiple sclerosis treatment, while having an advantage over other low-dose interferons in the form of reduced frequency of intramuscular injections.

[Susac syndrome, review and clinical case]. / Sindrom Susaka, obzor i opisanie klinicheskogo sluchaia.

Susac syndrome (SS) is an extremely rare neurological disorder characterized by symptoms of a clinical triad: encephalopathy, retinopathy and hearing loss. These problems arise from the microangiopathy of blood vessels that supply blood to the brain, the retina and the cochlea. SS is more common in young women. The authors present a literature review on the diagnosis and treatment of SS and the clinical observation of patients with classic signs of the disease triad.

[The new pegylated interferon beta-1a (sampeginterferon beta-1a, BCD-054) in the treatment of remitting multiple sclerosis]. / Novyi pegilirovannyi interferon beta-1a (sampéginterferon beta-1a, BCD-054) v terapii remittiruiushchego rasseiannogo skleroza.

AIM: To evaluate the efficacy and safety of BCD 054 180 µg and 240 µg administered once every 2 weeks for the treatment of remitting multiple sclerosis compared to placebo and low dose interferon beta-1a (LIB) 30 µg administered once weekly. Results of a 20 week blinded interim analysis from a double blind, comparative, randomised, placebo-controlled clinical study are included. MATERIAL AND METHODS: This multinational, multicentre, double blind, comparative, placebo-controlled study enrolled 399 patients with the diagnosis of remitting multiple sclerosis: 114 patients in the sampeginterferon beta 1a and LIB groups each and 57 patients in the placebo group. To ensure the objectivity of data, the study protocol includes a blinded interim analysis to demonstrate the superiority of BCD 054 over placebo based on the number of combined unique active lesions (CUA) on MRI scans after 20 weeks of treatment. RESULTS AND CONCLUSION: An integrated analysis of the efficacy, safety, pharmacokinetics, and pharmacodynamics was performed after 20 weeks of study. Mean CUA per scan was lower in the active treatment groups compared to placebo: 0,986±2,046, 0,619±1,055, 0,665±1,165, 1,673±2,376 (groups 1, 2, 3 and placebo group, respectively). The data for CUA per scan demonstrated the superiority of both BCD 054 180 µg and 240 µg over placebo. Patients receiving active treatment had fewer new and/or enlarging lesions after 20 weeks of treatment. The proportion of patients without new T2-weighted lesions was 74,3%, 86,7%, and 78,1% in groups 1, 2, and 3 compared to 64,9% in the placebo group. Manifestations of flu-like syndrome that is expected for interferon treatment were observed with the same incidence in all the active treatment groups. Its severity, duration or the need for symptomatic treatment did not appear to depend on the type of interferon used.

[The efficacy and safety of siponimod in the Russian population of patients with secondary progressive multiple sclerosis]. / Éffektivnost' i bezopasnost' siponimoda u patsientov s vtorichno-progressiruiushchim rasseiannym sklerozom v rossiiskoi populiatsii.

AIM: To study the efficacy and safety of siponimod in patients with secondary progressive multiple sclerosis (SPMS) in the Russian population of the EXPAND study. MATERIAL AND METHODS: Ninety-four patients with SPMS from Russia were included in the analysis. Sixty-three patients received siponimod and 31 patients received placebo. The primary endpoint of the study was time to 3-month confirmed disability progression (3m-CDP) events, other clinical and radiological endpoints were also evaluated. RESULTS: The siponimod group showed a 54% reduction in the risk of 3m-CDP compared with the placebo group (p=0.0334). Secondary endpoints also showed the advantage of the drug over placebo. In the siponimod group, mild adverse events associated with impaired liver function, as well as arterial hypertension, were more common. No patient left the study due to an adverse event. CONCLUSION: The use of siponimod in patients with SPMS in the Russian population reduced the risk of disability progression. Siponimod showed a favorable safety profile.

[Primary-progressive multiple sclerosis in Russia: a medical-sociological study involving patients and neurologists]. / Pervichno-progressiruiushchii rasseiannyi skleroz v Rossii: mediko-sotsiologicheskoe issledovanie s uchastiem patsientov i nevrologov.

The main results of a medical-sociological study aimed at the evaluation of the level of satisfaction with treatment in patients with primary progressive multiple sclerosis (PPMS) are presented. The survey was conducted in 19 regions of the Russian Federation and involved 437 patients with confirmed diagnosis of PPMS and 80 neurologists specialized in multiple sclerosis. The research was carried out by the All-Russian Public Organization of Disabled People with Multiple Sclerosis with the participation of the Russian Committee for Treatment and Research in Multiple Sclerosis. This is the first medical-sociological study in the Russian Federation involving patients with PPMS and neurologists. The study revealed typical medical and social problems patients with PPMS faced. A significant decrease in quality-of-life of PPMS patients was shown.

[Provision of alemtuzumab safety is one of the main components of pharmacovigilance]. / Obespechenie bezopasnosti terapii alemtuzumabom - odna iz glavnykh sostavliaiushchikh farmakonadzora.

Modern multiple sclerosis therapy with disease-modifying drugs is characterized by the risks of dangerous infectious complications. In the last 5 years, there have been several reports of severe, sometimes lethal, listeriosis infection in patients treated with alemtuzumab. This article presents a clinical case of lethal listeriosis meningoencephalitis, which developed within 7 days after the completion of the first cycle of alemtuzumab therapy. In January 2018, a meeting of the expert Council was held, at which the clinical recommendations published in 2017 were revised and updated.

[Polymorphic variants of the immune response genes as risk factors for primary progressive multiple sclerosis]. / Polimorfnye varianty genov immunnogo otveta kak faktory riska razvitiia pervichno-progressiruiushchego rasseiannogo skleroza.

AIM: To analyze the involvement of immune response genes in the pathogenesis of primary progressive multiple sclerosis (PPMS). MATERIAL AND METHODS: This multicenter study included 111 patients with PPMS from the Russian ethnic group. The association of PPMS with genes of immune system was analyzed by the study of polymorphic variants of genes of cytokines and genes of antigen-presenting cells. RESULTS AND CONCLUSION: The genotypes of IL-4 (rs2243250)*C/C and CLEC16A (rs6498169)*G/G were associated with PPMS in Russians. The association between the HLA-DRB1*15 and PPMS found out in other populations was confirmed in Russians.

[Clinical guidelines for the use of dimethyl fumarate in relapsing-remitting multiple sclerosis]. / Klinicheskie rekomendatsii po primeneniiu preparata dimetilfumarat pri remittiruiushche-retsidiviruiushchem rasseiannom skleroze.

Multiple sclerosis is a chronic demyelinating and neurodegenerative disease of the central nervous system, in which autoimmune inflammation and oxidative stress play essential pathogenetic roles. Activation and infiltration of immune cells in brain tissues, lipid peroxidation products, mitochondrial dysfunction, defective antioxidant protection, and many other pathological factors result in demyelination, axonal injury and death, and apoptosis of oligodendrocytes and neurons, all of which causes constant progression of the disease. The new oral agent for the treatment of relapsing-remitting multiple sclerosis (RRMS), dimethyl fumarate (DMF), helps change the pathogenetic mechanisms of the disease, thus decreasing the rate of exacerbations, slowing down disease progression, and reducing the risk of radiological progression of the disease.

[Primary progressive multiple sclerosis: current issues of timely diagnosis]. / Pervichno-progressiruiushchii rasseiannyi skleroz: sovremennoe sostoianie problemy svoevremennoi postanovki diagnoza.

This article presents a review of international data on primary progressive multiple sclerosis (PPMS) and an analysis of factors influencing timely diagnosis of PPMS in a number of regions of the Russian Federation.

[A retrospective analysis of the effect of pregnancy on the course of multiple sclerosis]. / Retrospektivnyi analiz vliianiia beremennosti na techenie rasseiannogo skleroza.

AIM: For a long time it was believed that pregnancy worsens the clinical course of multiple sclerosis. In several European countries, there have been several studies that have demonstrated remission of autoimmune aggression during pregnancy. We studied the effect of pregnancy on the course of multiple sclerosi. MATERIAL AND METHODS: A retrospective analysis of disease course of 279 patients was performed for the first time in three major Russian centers (Moscow, Novosibirsk, Tyumen). RESULTS AND CONCLUSION: There was a remission of autoimmune aggression during pregnancy. The use of DMT before pregnancy was a predictor of a more favorable course of the disease after delivery. An earlier beginning of DMT after delivery led to a significant risk reduction of relapses.

[The first results of a combined all-Russian study on clinical genetics of multiple sclerosis].

Multiple sclerosis is a classic multifactorial disease in which etiology interaction of external factors and structural features of a large number of genes plays an important role. Identifying risk factors for multiple sclerosis and creating an integrated model of pathogenesis are urgent tasks of neurology. Revealing true risk factors is possible only in studies with sufficient statistical power, so with a large amount of samples. We conducted the association study of CD40 gene's polymorphisms and multiple sclerosis among residents of the Russian Federation. The results demonstrated the need to combine data from different researchers in clinical studies to increase the power of the study.