Implementation status of pharmacological studies in the development of orphan drugs.

BACKGROUND: The nonclinical as well as clinical development of orphan drugs is difficult, owing to unknown pathophysiology and the absence of animal models. Both, the U.S. Food and Drug Administration (FDA) Guidance and European Medicines Agency (EMA) Guidelines, for orphan drug development describe non-clinical studies, but lack specific information, such as animal species and study design. Against this background, this study aimed to elucidate efficient methods for evaluating nonclinical efficacy based on a review report of orphan drugs approved in Japan. RESULTS: A total of 184 orphan drugs, including 84 anticancer and 100 non-anticancer drugs, approved in Japan from January 2010 to December 2019 were investigated. Some anticancer drugs progressed to clinical development without distinct efficacy data in nonclinical studies. Patient-derived cells have been used for some drugs due to a lack of established cell lines. Cells used for non-clinical studies were devised for drugs indicated for cancers resistant to prior therapies, tumours with specific amino acid mutations in the target molecules, and solid tumours with specific biomarkers. For some non-anticancer drugs, similar disease animal models and normal animals were used for evaluation, since animal models did not exist. Biomarkers have been used specifically for evaluation in normal animals and as endpoints in some clinical trials. CONCLUSIONS: It was possible to evaluate drug efficacy by flexibly designing nonclinical studies according to disease characteristics for potentials orphan drugs. These approaches, which are not described in detail in the EMA Guideline or FDA Guidance, may thus lead to approval.

Efficacy of sirolimus for epileptic seizures in childhood associated with focal cortical dysplasia type II.

OBJECTIVE: The efficacy of the mechanistic target of rapamycin inhibitor, sirolimus, was recently reported for patients more than 6 years of age by Kato et al. We evaluated the efficacy and safety of sirolimus in a 2-year-old patient with recurrent focal seizures with impaired consciousness after focal cortical dysplasia (FCD) type IIa resection. METHODS: The patient was a 2-year-old girl who had recurrent seizures after undergoing FCD resection at 4 months of age. The initial dose of sirolimus was 0.5 mg/day and was gradually increased using the trough blood concentration before oral administration as an index, and evaluation was performed at 92 weeks. RESULTS: The trough blood level of sirolimus was increased to 6.1 ng/mL and maintenance therapy was started at 40 weeks. Focal seizures with impairment of consciousness with tonic extension of the limbs decreased. No critically serious adverse events occurred. CONCLUSION: Sirolimus was effective against epileptic seizures from FCD type II even for a child under 5 years of age. There were no critically serious adverse events and administration could be continued.

Status of the Current Treatment Options and Potential Future Targets in Uterine Leiomyosarcoma: A Review.

Uterine leiomyosarcoma (uLMS) is the most common subtype of mesenchymal tumors in the uterus. This review aims to summarize the current standard therapies and the molecular properties of uLMS for novel molecular-targeted therapies. Although 65% of uLMS cases are diagnosed in stage I, the 5-year overall survival rate is less than 60%. The only effective treatment for uLMS is complete and early resection, and chemotherapy is the main treatment for unresectable advanced or recurrent cases. No chemotherapy regimen has surpassed doxorubicin monotherapy as the first-line chemotherapy for unresectable advanced or recurrent cases in terms of overall survival in phase 3 trials. As a second-line treatment, pazopanib, trabectedin, and eribulin are used, but their therapeutic effects are not sufficient, highlighting the urgent need for development of novel treatments. Recent developments in gene analysis have revealed that homologous recombination deficiency (HRD), including breast cancer susceptibility gene 2 (BRCA2) mutations, are frequently observed in uLMS. In preclinical studies and several case series, poly(adenosine diphosphate-ribose)polymerase inhibitors showed antitumor effects on uLMS cell lines with BRCA2 mutations or HRD and in recurrent or persistent cases of uLMS with BRCA2 mutations. Thus, HRD, including BRCA mutations, may be the most promising therapeutic target for uLMS.

Efficacy of bezafibrate for preventing myopathic attacks in patients with very long-chain acyl-CoA dehydrogenase deficiency.

BACKGROUND: Very long-chain acyl-CoA dehydrogenase deficiency (VLCADD) is a mitochondrial fatty acid oxidation disorder that causes episodic attacks, such as general fatigue, hypotonia, myalgia, and rhabdomyolysis accompanied by lack of energy. As yet, there are no preventative drugs for these VLCADD-associated metabolic attacks. PATIENTS AND METHODS: We conducted an open-label, non-randomized, multi-center study into the effects of bezafibrate on five patients with VLCADD. Bezafibrate was administered for 4 years, and we analyzed the number of myopathic attacks requiring hospitalization and treatment infusions. RESULTS: The number of myopathic attacks requiring infusions of 24 h or longer significantly decreased during the study period. The patients' ability to conduct everyday activities was also improved by the treatment. CONCLUSION: Our findings show the potential long-term efficacy of bezafibrate in preventing myopathic attacks for patients with VLCADD.

Open-label clinical trial of bezafibrate treatment in patients with fatty acid oxidation disorders in Japan; 2nd report QOL survey.

INTRODUCTION: Fatty acid oxidation disorders (FAODs) are rare diseases caused by a defective mitochondrial fatty acid oxidation (FAO) enzyme. We recently reported that bezafibrate improved patient quality of life (QOL) based on the SF-36 questionnaire score in patients with FAODs during a 50-week, open-label, clinical trial. Herein we conducted further survey assessments of the trial patients to define the long-term efficacy and safety of bezafibrate. MATERIALS AND METHODS: This trial was an open-label, non-randomized, and multicenter study of bezafibrate treatment in five patients with very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency and one patient with carnitine palmitoyltransferase-II (CPT-2) deficiency (median age, 15.9 years; range, 5.8-26.4 years). The bezafibrate administration was continued for a further 102-174 weeks after the 24-week treatment described in our previous study. QOL was quantitated using the 36-Item Short Form Health Survey (SF-36) questionnaire, which constitutes eight components: physical functioning (PF), role limitation due to physical problems, bodily pain, general health perception, vitality, social functioning, role limitation due to emotional problems, and mental health. RESULTS: PF was elevated in all patients and continued to rise during the study, with the total QOL scores increased from baseline in five of the six cases. In particular, three patients older than 20 years showed treatment efficacy, and all subcategories of QOL were elevated in two of these cases. CONCLUSION: Our findings supported one of the stated benefits of bezafibrate in improving QOL for patients with FAODs.

Cultured Epidermal Autografts from Clinically Revertant Skin as a Potential Wound Treatment for Recessive Dystrophic Epidermolysis Bullosa.

Inherited skin disorders have been reported recently to have sporadic normal-looking areas, where a portion of the keratinocytes have recovered from causative gene mutations (revertant mosaicism). We observed a case of recessive dystrophic epidermolysis bullosa treated with cultured epidermal autografts (CEAs), whose CEA-grafted site remained epithelized for 16 years. We proved that the CEA product and the grafted area included cells with revertant mosaicism. Based on these findings, we conducted an investigator-initiated clinical trial of CEAs from clinically revertant skin for recessive dystrophic epidermolysis bullosa. The donor sites were analyzed by genetic analysis, immunofluorescence, electron microscopy, and quantification of the reverted mRNA with deep sequencing. The primary endpoint was the ulcer epithelization rate per patient at 4 weeks after the last CEA application. Three patients with recessive dystrophic epidermolysis bullosa with 8 ulcers were enrolled, and the epithelization rate for each patient at the primary endpoint was 87.7%, 100%, and 57.0%, respectively. The clinical effects were found to persist for at least 76 weeks after CEA transplantation. One of the three patients had apparent revertant mosaicism in the donor skin and in the post-transplanted area. CEAs from clinically normal skin are a potentially well-tolerated treatment for recessive dystrophic epidermolysis bullosa.

Open-label clinical trial of bezafibrate treatment in patients with fatty acid oxidation disorders in Japan.

INTRODUCTION: Fatty acid oxidation disorders (FAODs) are rare diseases caused by defects in mitochondrial fatty acid oxidation (FAO) enzymes. While the efficacy of bezafibrate, a peroxisome proliferator-activated receptor agonist, on the in vitro FAO capacity has been reported, the in vivo efficacy remains controversial. Therefore, we conducted a clinical trial of bezafibrate in Japanese patients with FAODs. MATERIALS AND METHODS: This trial was an open-label, non-randomized, and multicenter study of bezafibrate treatment in 6 patients with very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency and 2 patients with carnitine palmitoyltransferase-II (CPT-2) deficiency (median age, 8.2 years; ranging from 5.8 to 26.4 years). Bezafibrate was administered for 6 months following a 6-month observation period. The primary endpoint was the frequency of myopathic attacks, and the secondary endpoints were serum acylcarnitines (ACs, C14:1 or C16 + C18:1), creatine kinase (CK) levels, degree of muscle pain (VAS; visual analog scale) during myopathic attacks, and quality of life (QOL; evaluated using validated questionnaires). RESULTS: The frequency of myopathic attacks after bezafibrate administration decreased in 3 patients, increased in 3, and did not change in 2. The CK, AC, and VAS values during attacks could be estimated in only three or four patients, but a half of the patients did not experience attacks before or after treatment. Changes in CK, AC, and VAS values varied across individuals. In contrast, three components of QOL, namely, physical functioning, role limitation due to physical problems (role physical), and social functioning, were significantly elevated. No adverse drug reactions were observed. CONCLUSION: In this study, the frequency of myopathic attacks and CK, AC, and VAS values during the attacks could not be evaluated due to several limitations, such as a small trial population. Our findings indicate that bezafibrate improves the QOL of patients with FAODs, but its efficacy must be examined in future investigations.