Stiripentol add-on therapy for drug-resistant focal epilepsy.

BACKGROUND: This is an updated version of the Cochrane Review first published in 2014 and last updated in 2020. For nearly 30% of people with epilepsy, current treatments do not control seizures. Stiripentol is an antiepileptic drug (AED) that was developed in France and was approved by the European Medicines Agency (EMA) in 2007 as an adjunctive therapy with valproate and clobazam for the treatment of Dravet syndrome. OBJECTIVES: To evaluate the efficacy and tolerability of stiripentol as add-on treatment for people with drug-resistant focal epilepsy who are taking AEDs. SEARCH METHODS: For the latest update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE on 28 March 2022. We contacted the manufacturer of stiripentol and epilepsy experts to identify published, unpublished and ongoing trials. SELECTION CRITERIA: Randomised controlled trials of add-on stiripentol in people with drug-resistant focal epilepsy. DATA COLLECTION AND ANALYSIS: Review authors independently selected trials for inclusion and extracted data. We investigated outcomes including 50% or greater reduction in seizure frequency, seizure freedom, adverse effects, treatment withdrawal and changes in quality of life. MAIN RESULTS: On the basis of our selection criteria, we included no new studies in the present review update. We included only one study from the original review (32 children with focal epilepsy). This study adopted a responder-enriched design and found no clear evidence of a reduction of 50% or more in seizure frequency (risk ratio (RR) 1.51, 95% confidence interval (CI) 0.81 to 2.82; low-certainty evidence) and no clear evidence of seizure freedom (RR 1.18, 95% CI 0.31 to 4.43; low-certainty evidence) when comparing add-on stiripentol with placebo. Stiripentol led to a greater risk of adverse effects considered as a whole (RR 2.65, 95% CI 1.08 to 6.47; low-certainty evidence). When we considered specific adverse effects, CIs were very wide and showed the possibility of substantial increases and small reductions in risks of neurological adverse effects (RR 2.65, 95% CI 0.88 to 8.01; low-certainty evidence). Researchers noted no clear reduction in the risk of study withdrawal (RR 0.66, 95% CI 0.30 to 1.47; low-certainty evidence), which was high in both groups (53.3% in placebo group and 35.3% in stiripentol group; low-certainty evidence). The external validity of this study was limited because only responders to stiripentol (i.e. participants experiencing a decrease in seizure frequency of 50% or greater during an open prerandomisation phase compared with baseline) were included in the randomised, add-on, placebo-controlled, double-blind phase. Furthermore, carry-over and withdrawal effects probably influenced outcomes related to seizure frequency. Very limited information derived from the only included study shows that adverse effects considered as a whole may occur more often with add-on stiripentol than with add-on placebo. AUTHORS' CONCLUSIONS: We have found no new studies since the last version of this review was published. Hence, we have made no changes to the conclusions as presented in previous versions. We can draw no conclusions to support the use of stiripentol as add-on treatment for drug-resistant focal epilepsy. Additional large, randomised, well-conducted trials are needed.

Antiepileptic Stiripentol May Influence Bones.

Bone structure abnormalities are increasingly observed in patients chronically treated with antiepileptic drugs (AEDs). The majority of the available data concern older conventional AEDs, while the amount of information regarding newer AEDs, including stiripentol, is limited. The aim of the study was to assess the effect of stiripentol on bones. For 24 weeks, male Wistar rats, received 0.9% sodium chloride (control group) or stiripentol (200 mg/kg/day) (STP group). In the 16th week of the study, we detected lower serum PINP levels in the STP group compared to the control group. In the 24th week, a statistically significant lower 1,25-dihydroxyvitamin D3 level, higher inorganic phosphate level and higher neutrophil gelatinase-associated lipocalin (NGAL) levels in serum were found in the STP group compared to the control. Micro X-ray computed tomography of the tibias demonstrated lower bone volume fraction, lower trabecular thickness, higher trabecular pattern factor and a higher structure model index in the stiripentol group. Considering the results of this experiment on rats which suggests that long-term administration of stiripentol may impair the cancellous bone microarchitecture, further prospective human studies seem to be justified. However, monitoring plasma vitamin D, calcium, inorganic phosphate and kidney function in patients on long-term stiripentol therapy may be suggested.

Starting stiripentol in adults with Dravet syndrome? Watch for ammonia and carnitine.

OBJECTIVE: Dravet syndrome (DS) is a rare cause of severe and pharmacoresistant epileptic encephalopathy. Stiripentol (STP) has a significant therapeutic benefit in the pediatric DS population. However, STP effects on adult patients have not been well studied. In our adult STP-naive DS patient population, STP initiation was associated with encephalopathy, despite decreases in valproate and clobazam dosage. Here we explored the cause and treatment of encephalopathic manifestations associated with STP in adults. METHODS: Twenty-eight patients with a confirmed clinical and genetic diagnosis of DS who attended the Adult Epilepsy Genetics Clinic were identified retrospectively. Patients who declined or discontinued STP after fewer than 3 months of use, patients who were deceased before starting STP or seizure-free when the genetic diagnosis was confirmed, and those who started STP before leaving the pediatric system (<18 years) were excluded. Levels of ammonia, carnitine, and other anti-epileptic drugs (AEDs) were observed for patients receiving STP. Patients with high ammonia levels who received carnitine supplementation were reevaluated. They were also offered an increased dosage of stiripentol if treatment with carnitine improved the encephalopathy. RESULTS: We observed hyperammonemic encephalopathy in 77% of patients treated with STP. In seven of nine patients, we observed a rate of improvement in ammonia levels of 35% (95% confidence interval [CI] 21%-49%) at a mean carnitine dose of 991 ± 286 mg/d (range 660-1320 mg/d). Five patients whose ammonia levels normalized were also offered an increase in STP dose and they were able to tolerate higher doses with improvement in side effects. Despite such adjustments, the mean maximum stiripentol dose reached was 14.89 ± 8.72 mg/kg/d, which is lower than what is typically recommended in children (50 mg/kg/d). SIGNIFICANCE: We report hyperammonemia in adult STP-naive patients who were on valproate and clobazam, despite dose reduction of the latter drugs. We also report that treatment with carnitine improved hyperammonemia, allowing the continuation of STP.

Stiripentol add-on therapy for drug-resistant focal epilepsy.

BACKGROUND: This is an updated version of the Cochrane Review first published in 2014, and last updated in 2018. For nearly 30% of people with epilepsy, seizures are not controlled by current treatments. Stiripentol is an antiepileptic drug (AED) that was developed in France and was approved by the European Medicines Agency (EMA) in 2007 for the treatment of Dravet syndrome as an adjunctive therapy with valproate and clobazam. OBJECTIVES: To evaluate the efficacy and tolerability of stiripentol as add-on treatment for people with drug-resistant focal epilepsy who are taking AEDs. SEARCH METHODS: For the latest update, we searched the following databases on 27 February 2020: Cochrane Register of Studies (CRS Web); and MEDLINE (Ovid, 1946 to 26 February 2020). CRS Web includes randomised or quasi-randomised controlled trials from the Specialized Registers of Cochrane Review Groups including Epilepsy, Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform (ICTRP). We contacted Biocodex (the manufacturer of stiripentol) and epilepsy experts to identify published, unpublished and ongoing trials. SELECTION CRITERIA: Randomised, controlled, add-on trials of stiripentol in people with drug-resistant focal epilepsy. DATA COLLECTION AND ANALYSIS: Review authors independently selected trials for inclusion and extracted data. We investigated outcomes including 50% or greater reduction in seizure frequency, seizure freedom, adverse effects, treatment withdrawal and changes in quality of life. MAIN RESULTS: On the basis of our selection criteria, we included no new studies in the present review update. We included only one study from the earlier review (32 children with focal epilepsy). This study adopted a responder-enriched design and found no clear evidence of a reduction in seizure frequency (≥ 50% seizure reduction) (risk ratio (RR) 1.51, 95% confidence interval (CI) 0.81 to 2.82; low-certainty evidence) or evidence of seizure freedom (RR 1.18, 95% CI 0.31 to 4.43; low-certainty evidence) when add-on stiripentol was compared with placebo. Stiripentol led to a greater risk of adverse effects considered as a whole (RR 2.65, 95% CI 1.08 to 6.47; low-certainty evidence). When we considered specific adverse events, confidence intervals were very wide and showed the possibility of substantial increases and small reductions in risks of neurological adverse effects (RR 2.65, 95% CI 0.88 to 8.01; low-certainty evidence) and gastrointestinal adverse effects (RR 11.56, 95% CI 0.71 to 189.36; low-certainty evidence). Researchers noted no clear reduction in the risk of study withdrawal (RR 0.66, 95% CI 0.30 to 1.47; low-certainty evidence), which was high in both groups (35.0% in add-on placebo and 53.3% in stiripentol group; low-certainty evidence). The external validity of this study was limited because only responders to stiripentol (i.e. patients experiencing a ≥ 50% decrease in seizure frequency compared with baseline) were included in the randomised, add-on, placebo-controlled, double-blind phase. Furthermore, carry-over and withdrawal effects probably influenced outcomes related to seizure frequency. Very limited information derived from the only included study shows that adverse effects considered as a whole seemed to occur significantly more often with add-on stiripentol than with add-on placebo. AUTHORS' CONCLUSIONS: We have found no new studies since the last version of this review was published. Hence, we have made no changes to the conclusions of this update as presented in the initial review. We can draw no conclusions to support the use of stiripentol as add-on treatment for drug-resistant focal epilepsy. Additional large, randomised, well-conducted trials are needed.

Piperlongumine, a potent anticancer phytotherapeutic: Perspectives on contemporary status and future possibilities as an anticancer agent.

Piperlongumine, a white to beige biologically active alkaloid/amide phytochemical, has high pharmacological relevance as an anticancer agent. Piperlongumine has several biological activities, including selective cytotoxicity against multiple cancer cells of different origins at a preclinical level. Several preclinical studies have documented the anticancer potential of piperlongumine through its targeting of multiple molecular mechanisms, such as cell cycle arrest, anti-angiogenesis, anti- invasive and anti-metastasis pathways, autophagy pathways, and intrinsic apoptotic pathways in vitro and in vivo. Mechanistically, piperlongumine inhibits cancer growth by resulting in the accumulation of intracellular reactive oxygen species, decreasing glutathione and chromosomal damage, or modulating key regulatory proteins, including PI3K, AKT, mTOR, NF-kß, STATs, and cyclin D1. Furthermore, combined treatment with piperlongumine potentiates the anticancer activity of conventional chemotherapeutics and overcomes resistance to chemo- and radio- therapy. Nanoformulation of piperlongumine has been associated with increased aqueous solubility and bioavailability and lower toxicity, thus enhancing therapeutic efficacy in both preclinical and clinical settings. The current review highlights anticancer studies on the occurrence, chemical properties, chemopreventive mechanisms, toxicity, bioavailability, and pharmaceutical relevance of piperlongumine in vitro and in vivo.

Stiripentol: A Review in Dravet Syndrome.

Stiripentol (Diacomit®) is an orally-active, structurally unique anti-epileptic drug (AED) with multiple potential mechanisms of action, including enhancement of central γ-aminobutyric acid transmission. In the EU, stiripentol is indicated for use in conjunction with clobazam and valproate as adjunctive therapy of refractory generalized tonic-clonic seizures in patients with Dravet syndrome (DS; previously known as severe myoclonic epilepsy of infancy), whose seizures are not adequately controlled with clobazam and valproate. This approval (and similar DS indications in the USA, Canada and Japan), reflect the results of the STICLO studies, two small, randomized controlled trials in which stiripentol as adjunctive therapy was associated with a markedly superior response rate after 2 months compared with placebo in patients aged between 3 and ≈ 21 years with DS that was inadequately controlled with clobazam and valproate. These short-term results have subsequently been supported and extended by findings from longer-term, open-label, observational studies, including a retrospective longitudinal cohort study, which showed that the efficacy of combining stiripentol with clobazam and valproate when started at paediatric age was maintained in mid-adulthood with up to 24 years of exposure, and up to 40 years of age. Drowsiness, appetite loss, weight loss, ataxia and tremor are the most common adverse events associated with the addition of stiripentol to clobazam and valproate. Based on the available evidence, stiripentol, as an adjunct to clobazam and valproate, is a demonstrably beneficial and generally well-tolerated second-line treatment for patients with DS.

Stiripentol for the treatment of seizures in Dravet syndrome.

INTRODUCTION: Dravet syndrome is an early childhood-onset epilepsy syndrome characterized by drug-resistant seizures, frequent episodes of status epilepticus, and the development of neurocognitive impairment. Seizure freedom in this condition is rare and there is a higher rate of sudden unexplained death in epilepsy patients (SUDEP) than other epilepsy syndromes. Stiripentol is a recently approved medication with an indication specifically for the treatment of seizures in children with Dravet syndrome. Areas covered: Review of relevant literature including the current and emerging treatment of seizures in children with Dravet syndrome, with a focus on stiripentol. This includes a review of the literature regarding the mechanism of action, clinical efficacy, and safety/tolerability of stiripentol. Expert opinion: Stiripentol has been available through expanded access programs resulting in a reduction of seizures and episodes of status epilepticus. With the Federal Drug Administration (FDA) approval, this treatment option will be more readily available to the Dravet syndrome population in the United States. The approval comes at a time of other treatment options also receiving approval (cannabidiol) and several products in ongoing studies (fenfluramine, TAK-935) providing additional treatment options and hope on the horizon for those impacted by this severe epilepsy syndrome.

Marked efficacy of combined three-drug therapy (Sodium Valproate, Topiramate and Stiripentol) in a patient with Dravet syndrome.

WHAT IS KNOWN AND OBJECTIVE: Dravet syndrome (DS) is an intractable epilepsy syndrome. The three-drug combination therapy of sodium valproate (VPA), clobazam (CLB) and stiripentol (STP) is recommended worldwide. CASE SUMMARY: We present a case of DS, in which treatment with CLB could not be continued because of the appearance of adverse reactions to it. Replacement with topiramate (TPM) proved to be markedly effective. WHAT IS NEW AND CONCLUSION: It is suggested that combination therapy with VPA, TPM and STP is for DS epilepsy.

Antiepileptic drugs for the treatment of infants with severe myoclonic epilepsy.

BACKGROUND: This is an updated version of the original Cochrane review published in 2015, Issue 10.Severe myoclonic epilepsy in infants (SMEI), also known as Dravet syndrome, is a rare, refractory form of epilepsy, for which stiripentol (STP) has been recently licensed as add-on therapy. OBJECTIVES: To evaluate the efficacy and tolerability of STP and other antiepileptic drug treatments (including ketogenic diet) for patients with SMEI. SEARCH METHODS: For the latest update we searched the Cochrane Epilepsy Group Specialized Register (20 December 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO, 20 December 2016), MEDLINE (Ovid, 1946 to 20 December 2016) and ClinicalTrials.gov (20 December 2016). Previously we searched the World Health Organization (WHO) International Clinical Trials Registry Platform ICTRP, but this was not usable at the time of this update. We also searched the bibliographies of identified studies for additional references. We handsearched selected journals and conference proceedings and imposed no language restrictions. SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-randomised controlled trials; double- or single-blinded or unblinded trials; and parallel-group studies. Administration of at least one antiepileptic drug therapy given singly (monotherapy) or in combination (add-on therapy) compared with add-on placebo or no add-on treatment. DATA COLLECTION AND ANALYSIS: Review authors independently selected trials for inclusion according to predefined criteria, extracted relevant data and evaluated the methodological quality of trials. We assessed the following outcomes: 50% or greater seizure reduction, seizure freedom, adverse effects, proportion of dropouts and quality of life. We assessed outcomes by using a Mantel-Haenszel meta-analysis to calculate risk ratios (RRs) with 95% confidence intervals (95% CIs). MAIN RESULTS: Since the last version of this review no new studies have been found. Specifically, we found no RCTs assessing drugs other than STP. The review includes two RCTs evaluating use of STP (total of 64 children). Both studies were generally at unclear risk of bias. A significantly higher proportion of participants had 50% or greater reduction in seizure frequency in the STP group compared with the placebo group (22/33 versus 2/31; RR 10.40, 95% CI 2.64 to 40.87). A significantly higher proportion of participants achieved seizure freedom in the STP group compared with the placebo group (12/33 versus 1/31; RR 7.93, 95% CI 1.52 to 41.21). Investigators found no significant differences in proportions of dropouts from the STP group compared with the placebo group (2/33 versus 8/31; RR 0.24, 95% CI 0.06 to 1.03). Only one study explicitly reported the occurrence of side effects, noting that higher proportions of participants in the STP group experienced side effects than in the placebo group (100% versus 25%; RR 3.73, 95% CI 1.81 to 7.67). We rated the quality of the evidence as low to moderate according to GRADE criteria, as most information is from studies judged to be at an unclear risk of bias. AUTHORS' CONCLUSIONS: Data derived from two small RCTs indicate that STP is significantly better than placebo with regards to 50% or greater reduction in seizure frequency and seizure freedom. Adverse effects occurred more frequently with STP. Additional adequately powered studies with long-term follow-up should be conducted to unequivocally establish the long-term efficacy and tolerability of STP in the treatment of patients with SMEI.

Stiripentol in the Management of Epilepsy.

Stiripentol is a structurally unique antiepileptic drug that has several possible mechanisms of action, including diverse effects on the gamma-aminobutyric acid (GABA)-A receptor and novel inhibition of lactate dehydrogenase. Because of its inhibition of several cytochrome P450 enzymes, it has extensive pharmacokinetic interactions, which often necessitates reduction in doses of certain co-therapies, particularly clobazam. Stiripentol also has a neuroprotective action, by reducing calcium-mediated neurotoxicity. Evidence of its efficacy is most robust for Dravet syndrome, where stiripentol added to clobazam and valproic acid reduces seizure frequency and severity in the majority of cases. Small case series have also suggested benefit for malignant migrating partial seizures in infancy, super-refractory status epilepticus, and intractable focal epilepsy, although larger prospective studies are needed in these disorders.

Audit of use of stiripentol in adults with Dravet syndrome.

OBJECTIVES: There are very few data available in the literature on the use of stiripentol in adults with Dravet syndrome (DS). DS cases are increasingly recognized in adulthood, and more children with DS now survive to adulthood. The aim of the study was to document the effectiveness and tolerability of stiripentol in adults with DS. MATERIAL AND METHODS: We conducted an observational clinical audit in the epilepsy service of the National Hospital for Neurology and Neurosurgery, London (UK). RESULTS: We included 13 adult subjects with DS (eight females, five males). The responder (defined as more than 50% reduction in all seizure types) rate was 3/13 (23%) at 36 months. The following other outcomes were reported: seizure exacerbation (3/13, 23%), no change (3/13, 23%), less than 50% reduction in seizures (2/13, 15%), more than 50% reduction in generalized tonic-clonic seizures but no other seizure types (1/13, 8%), undefined response (1/13, 8%). The retention rate was 62% after 1 year and 31% after 5 years. Adverse effects were reported in 7/13 (54%): the most frequent were anorexia, weight loss, unsteadiness and tiredness. Withdrawal due to adverse effects occurred in 3/13 (23%). CONCLUSIONS: Compared with previous studies on children with DS, our results show a lower responder rate and a similar tolerability profile. Stiripentol can be effective with a good tolerability profile. Our audit is small, but supports the use of stiripentol in adults with DS when first-line treatments are ineffective or not tolerated, in keeping with published guidelines.

Stiripentol and vigabatrin current roles in the treatment of epilepsy.

INTRODUCTION: Stiripentol and vigabatrin are the two anticonvulsant drugs currently approved in severe infantile-onset epilepsies, respectively Dravet syndrome and infantile spasms. AREAS COVERED: For both, the indication was discovered by chance thanks to an exploratory study. Both demonstrated indisputable efficacy through randomized-controlled trials. Stiripentol as adjunctive therapy to clobazam and valproate performed better than placebo, and vigabatrin as first-line monotherapy better than the reference steroid therapy in spasms due to tuberous sclerosis. At one-year treatment vigabatrin and steroids were equally efficient in the other etiologies of spasms. However, it took more than 20 years for both drugs to be approved world-wide. EXPERT OPINION: Stiripentol suffered from pharmacokinetic potentiation of clobazam, thus raising the question whether it was efficient per se. Finally, animal models and pharmacogenetic data on CYP2C19 confirmed its specific anticonvulsant effect. Stiripentol (in comedication with clobazam and valproate) is therefore to be recommended for Dravet patients. Vigabatrin was found to have a frequent and irreversible retinal toxicity, which required an alternative visual testing to be detected in young children. Today the benefit/risk ratio of vigabatrin as first-line is considered to be positive in infantile spasms, given the severity of this epilepsy and the lack of a safer alternative therapy.

Pharmacological considerations in the use of stiripentol for the treatment of epilepsy.

INTRODUCTION: Despite the fact that more than 20 antiepileptic drugs (AEDs) are currently available, about one-third of patients still present drug resistance. Further efforts are required to develop novel and more efficacious therapeutic strategies, especially for refractory epileptic syndromes showing few and anecdotic therapeutic options. AREAS COVERED: Stiripentol (STP) is a second generation AED that shows GABAergic activity, with immature brain selectivity, and an indirect metabolic action on co-administered AEDs. Two pivotal studies demonstrated STP efficacy in patients with Dravet syndrome with refractory partial seizures, and marketing authorization in Europe, Canada and Japan was granted thereafter. Post-marketing surveys reported a good efficacy and tolerability profile. In addition, interesting data is currently emerging regarding off-label experimentation of STP in other forms of epilepsy. EXPERT OPINION: STP is an important addition to the limited treatment options available for patients resistant to common AEDs. The possibility to inhibit seizures through the metabolic pathway of lactate dehydrogenase and the inhibitory effects on the entry of Na(+) and Ca(2+) are the most recent findings to emerge about STP and could be proof of its neuroprotective action. Moreover, its positive effects on cognitive function, its good safety and tolerability profile and the increasing data about STP efficacy on other refractory epileptic syndromes may prove to be fertile grounds for further investigation.

Antiepileptic drugs for the treatment of infants with severe myoclonic epilepsy.

BACKGROUND: This is an updated version of the original Cochrane review published in Issue 11, 2013.Severe myoclonic epilepsy in infants (SMEI), also known as Dravet syndrome, is a rare, refractory form of epilepsy, for which stiripentol (STP) has been recently licensed as add-on therapy. OBJECTIVES: To evaluate the efficacy and tolerability of STP and other antiepileptic drug treatments (including ketogenic diet) for patients with SMEI. SEARCH METHODS: We searched the Cochrane Epilepsy Group Specialised Register (27 April 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 27 April 2015) and MEDLINE (1946 to 27 April 2015). We systematically searched the online trials registry ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform and the bibliographies of identified studies for additional references. We handsearched selected journals and conference proceedings and imposed no language restrictions. SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-randomised controlled trials; double- or single-blinded or unblinded trials; and parallel-group studies. Administration of at least one antiepileptic drug therapy given singly (monotherapy) or in combination (add-on therapy) compared with add-on placebo or no add-on treatment. DATA COLLECTION AND ANALYSIS: Review authors independently selected trials for inclusion according to predefined criteria, extracted relevant data and evaluated the methodological quality of trials. We assessed the following outcomes: 50% or greater seizure reduction, seizure freedom, adverse effects, proportion of dropouts and quality of life. We assessed outcomes by using a Mantel-Haenszel meta-analysis to calculate risk ratios (RRs) with 95% confidence intervals (95% CIs). MAIN RESULTS: In the updated search, we identified no additional studies suitable for inclusion. We found no RCTs assessing drugs other than STP. The previous version of this review included two RCTs evaluating use of STP (total of 64 children). Both studies were generally at unclear risk of bias. A significantly higher proportion of participants had 50% or greater reduction in seizure frequency in the STP group compared with the placebo group (22/33 vs 2/31; RR 10.40, 95% CI 2.64 to 40.87). A significantly higher proportion of participants achieved seizure freedom in the STP group compared with the placebo group (12/33 vs 1/31; RR 7.93, 95% CI 1.52 to 41.21). Investigators found no significant differences in proportions of dropouts from the STP group compared with the placebo group (2/33 vs 8/31; RR 0.24, 95% CI 0.06 to 1.03). Only one study explicitly reported the occurrence of side effects, noting that higher proportions of participants in the STP group experienced side effects than in the placebo group (100% vs 25%; RR 3.73, 95% CI 1.81 to 7.67). AUTHORS' CONCLUSIONS: Data derived from two small RCTs indicate that STP is significantly better than placebo with regards to 50% or greater reduction in seizure frequency and seizure freedom. Adverse effects occurred more frequently with STP. Additional adequately powered studies with long-term follow-up should be conducted to unequivocally establish the long-term efficacy and tolerability of STP in the treatment of patients with SMEI.

Drug-repositioning screening identified piperlongumine as a direct STAT3 inhibitor with potent activity against breast cancer.

Signal transducer and activator of transcription (STAT) 3 regulates many cardinal features of cancer including cancer cell growth, apoptosis resistance, DNA damage response, metastasis, immune escape, tumor angiogenesis, the Warburg effect and oncogene addiction and has been validated as a drug target for cancer therapy. Several strategies have been used to identify agents that target Stat3 in breast cancer but none has yet entered into clinical use. We used a high-throughput fluorescence microscopy search strategy to identify compounds in a drug-repositioning library (Prestwick library) that block ligand-induced nuclear translocation of Stat3 and identified piperlongumine (PL), a natural product isolated from the fruit of the pepper Piper longum. PL inhibited Stat3 nuclear translocation, inhibited ligand-induced and constitutive Stat3 phosphorylation, and modulated expression of multiple Stat3-regulated genes. Surface plasmon resonance assay revealed that PL directly inhibited binding of Stat3 to its phosphotyrosyl peptide ligand. Phosphoprotein antibody array analysis revealed that PL does not modulate kinases known to activate Stat3 such as Janus kinases, Src kinase family members or receptor tyrosine kinases. PL inhibited anchorage-independent and anchorage-dependent growth of multiple breast cancer cell lines having increased pStat3 or total Stat3, and induced apoptosis. PL also inhibited mammosphere formation by tumor cells from patient-derived xenografts. PL's antitumorigenic function was causally linked to its Stat3-inhibitory effect. PL was non-toxic in mice up to a dose of 30 mg/kg/day for 14 days and caused regression of breast cancer cell line xenografts in nude mice. Thus, PL represents a promising new agent for rapid entry into the clinic for use in treating breast cancer, as well as other cancers in which Stat3 has a role.

ß-l-1-[5-(E-2-bromovinyl)-2-(hydroxymethyl)-1,3-(dioxolan-4-yl)] uracil (l-BHDU) prevents varicella-zoster virus replication in a SCID-Hu mouse model and does not interfere with 5-fluorouracil catabolism.

The alphaherpesvirus varicella-zoster virus (VZV) causes chickenpox and shingles. Current treatments are acyclovir (ACV) and its derivatives, foscarnet and brivudine (BVdU). Additional antiviral compounds with increased potency and specificity are needed to treat VZV, especially to treat post-herpetic neuralgia. We evaluated ß-l-1-[5-(E-2-bromovinyl)-2-(hydroxymethyl)-1,3-(dioxolan-4-yl)] uracil (l-BHDU, 1) and 5'-O-valyl-l-BHDU (2) in three models of VZV replication: primary human foreskin fibroblasts (HFFs), skin organ culture (SOC) and in SCID-Hu mice with skin xenografts. The efficacy of l-BHDU in vivo and its drug-drug interactions were previously not known. In HFFs, 200µM l-BHDU was noncytotoxic over 3days, and l-BHDU treatment reduced VZV genome copy number and cell to cell spread. The EC50 in HFFs for l-BHDU and valyl-l-BHDU were 0.22 and 0.03µM, respectively. However, l-BHDU antagonized the activity of ACV, BVdU and foscarnet in cultured cells. Given its similar structure to BVdU, we asked if l-BHDU, like BVdU, inhibits 5-fluorouracil catabolism. BALB/c mice were treated with 5-FU alone or in combination with l-BHDU or BVdU. l-BHDU did not interfere with 5-FU catabolism. In SCID-Hu mice implanted with human skin xenografts, l-BHDU and valyl-l-BHDU were superior to ACV and valacyclovir. The maximum concentration (Cmax) levels of l-BHDU were determined in mouse and human tissues at 2h after dosing, and comparison of concentration ratios of tissue to plasma indicated saturation of uptake at the highest dose. For the first time, an l-nucleoside analog, l-BHDU, was found to be effective and well tolerated in mice.

Reassessment of stiripentol pharmacokinetics in healthy adult volunteers.

Because children who have been receiving stiripentol for the treatment of Dravet syndrome for more than 10 years are now becoming young adults, it is important to accurately characterize stiripentol pharmacokinetics in this age range. A double-blind placebo-controlled dose ranging study was therefore conducted to investigate the pharmacokinetics and tolerability of stiripentol in 12 healthy volunteers. Each subject received 3 single doses of stiripentol (500, 1000, and 2000 mg) separated by a wash-out period of 1 week. Pharmacokinetics of stiripentol was analyzed for each dose by non-compartmental analysis. Median area under the curve (AUC), terminal elimination half-life (t1/2,z) and maximal concentration (Cmax) were calculated for between-dose comparison. Safety was evaluated based on both clinical and biological criteria. Oppositely to previous results, there was no concentration rebounds in the elimination phase, which could be the consequence of the food intake. A more than proportional increase in the AUC was observed, associated with a significant increase in the t1/2,z, for increasing doses (median AUC of 8.3, 31 and 88 mgh/L, and median t1/2,z of 2, 7.7 and 10h for the 500, 1000, and 2000 mg doses respectively), which confirmed the Michaelis-Menten pharmacokinetics of Stiripentol. However, dose-normalized Cmax did not significantly vary between doses. Median Michaelis-Menten parameters were 117 mg/h for Vmax and 1.9 mg/L for Km. No safety concern was observed during the study. The present study allowed a better characterization of the disposition phase of stiripentol and confirmed its non-linear pharmacokinetic behaviour. Further pharmacokinetic/pharmacodynamic studies would be useful to determine the optimal dose of stiripentol for the treatment of Dravet patients in adulthood.

Effectiveness of add-on stiripentol to clobazam and valproate in Japanese patients with Dravet syndrome: additional supportive evidence.

PURPOSE: To evaluate the efficacy and safety of stiripentol as add-on therapy in Japanese patients with Dravet syndrome treated with clobazam (CLB) and valproate (VPA). METHODS: In this open-label study, patients aged 1-30 years entered a 4-week baseline phase, followed by a 4-week stiripentol dose-adjustment and 12-week fixed-dose phase. The primary efficacy endpoint was responder rate (proportion of patients with a ≥50% reduction from baseline phase in clonic or tonic-clonic seizure frequency over the last 4 weeks of fixed-dose treatment [target phase]). Safety and pharmacokinetics were also assessed. KEY FINDINGS: Of 27 patients screened in the baseline phase, 24 patients entered the dose-adjustment phase. All patients completed the study. Responder rate was 66.7% (16/24, 95% CI: 44.7-84.4%), and four patients became free from clonic or tonic-clonic seizures. The duration of clonic or tonic-clonic seizures was also significantly reduced in the target versus baseline phase. The most frequent adverse events were somnolence, anorexia, ataxia, nasopharyngitis and γ-glutamyl transpeptidase increase, all of which were of mild-to-moderate severity. Stiripentol plasma concentration in the fixed-dose phase was 4-25 µg/mL. After adding stiripentol to CLB and VPA, the minimum plasma concentrations of CLB and N-desmethyl-CLB (NCLB) increased and that of 4'-hydroxy-N-desmethyl-CLB(OH-NCLB) decreased, while those of VPA and bromide (optionally used) were not affected. SIGNIFICANCE: Add-on stiripentol to CLB and VPA was well tolerated and significantly decreased clonic or tonic-clonic seizures in patients with Dravet syndrome.