Orphan drug development in alpha-1 antitypsin deficiency.

Alpha-1 antitrypsin deficiency (AATD, OMIM #613490) is a rare metabolic disorder affecting lungs and liver. The purpose of this study is to assess the impact of the US orphan drug act on AATD by providing a quantitative clinical-regulatory insight into the status of FDA orphan drug approvals and designations for compounds intended to treat AATD. This is across-sectional analysis of the FDA database for orphan drug designations. Primary endpoint: orphan drug approvals. Secondary endpoint: orphan drug designations by the FDA. Close of database was 16 July 2021. STROBE criteria were respected. Primary outcome: one compound, alpha-1-proteinase inhibitor (human) was approved as an orphan drug in 1987 with market exclusivity until 1994. Secondary outcome: sixteen compounds received FDA orphan drug designation including protein, anti-inflammatory, mucolytic, gene, or cell therapy. Drug development activities in AATD were comparable to other rare conditions and led to the FDA-approval of one compound, based on a relatively simple technological platform. The current unmet medical need to be addressed are extrapulmonary manifestations, in this case the AATD-associated liver disease. Orphan drug development is actually focusing on (1) diversified recombinant AAT production platforms, and (2) innovative gene therapies, which may encompass a more holistic therapeutic approach.

Augmentation therapy with human alpha-1-proteinase inhibitor reduces exacerbations in patient with bronchiectasis and alpha-1-antitrypsin deficiency.

Alpha-1-antitrypsin deficiency (AATD) is a rare cause of noncystic fibrosis (CF) bronchiectasis. The benefits of augmentation therapy in patients with chronic obstructive pulmonary disease (COPD) and pulmonary emphysema are well established. The role of augmentation therapy in AATD bronchiectasis in patients without pulmonary emphysema is not clear. We present the case of a 53-year-old woman (never smoker) who presented with increased susceptibility to infection, productive cough, and intermittent hemoptysis. Pulmonary function testing revealed restrictive impairment [VC 2,7 l (83% of pred.), FEV1 2,3 l (86% of pred.)]. A CT scan of the chest showed marked basal bronchiectasis with mucoid impaction, surrounding consolidation, and no emphysema. Despite frequent use of inhalation therapy, a satisfactory control of symptoms and exacerbations was not achieved. In the course of extended diagnostics regarding the genesis of bronchiectasis, a reduced alpha-1-antitrypsin (AAT) serum level was detected, and a genetic test revealed a homozygous Pi*ZZ genotype. We started augmentation therapy with AAT (Respreeza®, CLS Behring) at the dose of 60 mg/kg per week; the therapy was well tolerated by the patient, and she reported clinical improvement with a reduction in exacerbation frequency. AAT is a serine protease inhibitor and plays a major role in regulating inflammatory activities, in particular by inhibiting neutrophil elastase (NE). The present case illustrates the positive effect of augmentation therapy, including patients without airway obstruction. Among other causes, AATD should be considered as a possible cause of bronchiectasis, and the effects of augmentation therapy for this indication need to be prospectively studied.

Tumor response to irinotecan is associated with CYP3A5 expression in colorectal cancer.

Recently, a tumor-autonomous cytochrome P450 (CYP)-3A5-mediated resistance to cancer therapy has been demonstrated in pancreatic ductal adenocarcinoma. Expression of CYP3A5, which is involved in the degradation of irinotecan, has also been reported in colorectal cancer (CRC). The aim of the present study was to analyze CYP3A5 expression in the normal colon, colon adenoma, CRC and normal tissues, as well as to examine whether CYP3A5 expression in CRC has an impact on tumor response to irinotecan treatment. Immunohistochemistry was used to assess 85 tissue samples from 65 patients with CRC, along with 15 samples of normal colon and 45 samples of colon adenoma (including tubular, tubulovillous, and sessile serrated adenomas), and a tissue microarray (TMA) comprised of 26 different normal tissue types. Expression of CYP3A5 was evaluated with a semi-quantitative score. Tumor response to irinotecan therapy was assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 guidelines. In normal tissues, CYP3A5 was expressed in epithelial cells of the colon, gallbladder, kidney, liver, small intestine, stomach, thyroid gland and tonsil, as well as in nerves. Expression in colon mucosa was heterogeneous, with only weak staining in the minority of specimens. CYP3A5 exhibited markedly higher expression in adenomas compared with normal colon tissues. A statistically significant inverse correlation was identified between CYP3A5 expression in CRC tissues and tumor response to irinotecan therapy. Irinotecan treatment itself did not alter CYP3A5 expression in CRC tissues. As CYP3A5 is involved in the degradation of irinotecan, the significantly higher intratumoral expression of CYP3A5 in patients with CRC who do not respond to irinotecan-based chemotherapy may indicate a causal role of CYP3A5 in tumor resistance.