The risk-based approach to ATMP development - generally accepted by regulators but infrequently used by companies.

Advanced therapy medicinal products (ATMPs) are the cutting edge of drug innovation. ATMPs have different challenges than other drug classes. To accommodate these challenges and facilitate science-driven development, flexibility in the requirements to demonstrate the safety and efficacy of this rapidly evolving drug class is necessary. To create flexibility, the European Union introduced the risk-based approach. This approach provides the possibility of omitting guideline-based studies based on risk analyses. To gain insight into the effect of the risk-based approach on the non-clinical development of ATMPs, two questions are addressed in this paper. Firstly, "Do companies use a risk-based approach for the non-clinical development of ATMPs?" and, secondly, "Does the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) accept non-clinical development programs based on the risk-based approach?" Scientific advice letters formulated by the CHMP were analyzed. The risk-based approach was used to justify deviations from the guidelines in the majority (75%) of the cases. The CHMP accepted 40% of the proposals to omit studies and stated that additional data was necessary to make an informed decision for 35% of the proposals. This indicates that the risk-based approach facilitates the science-driven development of ATMPs.

Conditional approval and approval under exceptional circumstances as regulatory instruments for stimulating responsible drug innovation in Europe.

The need for fast drug innovation and the public demand for risk-free drugs creates a dilemma for regulatory authorities: less restrictive procedures involve uncertainties about benefit/risk profiles of new drugs. The European Union has introduced two instruments that regulate early market access: conditional approvals (CAs) and approvals under exceptional circumstances (ECs). We have studied whether these instruments compromise the safety of new drugs and whether they lead to earlier access to innovative drugs. Our study shows that neither of these regulatory pathways accelerates the approval process for innovative drugs. However, the CA pathway shortens the clinical development period. Approvals under ECs are associated with longer clinical development periods, but this regulatory pathway may open up opportunities for specific drugs to be admitted into the market because less comprehensive data are required. Despite the fact that these advanced approvals are based on limited safety databases, there are no special safety issues associated with using these pathways.

A network of heterogeneous hydrogen bonds in GNRA tetraloops.

RNA hairpin loops containing a GNRA consensus sequence are the most frequently occurring hairpins in a variety of prokaryotic and eukaryotic RNAs. These tetraloops play important functional roles in RNA folding, in RNA-RNA tertiary interactions and as protein binding sites. Homo and heteronuclear NMR spectroscopy have been used to determine the structures of the most abundant members of the GNRA tetraloop family: the GAGA, GCAA and GAAA loops closed by a C-G base pair. Analysis of the structures of these three hairpin loops reveals a network of heterogeneous hydrogen bonds. The loops contain a G-A base pair, a G base-phosphate hydrogen bond and several 2' OH-base hydrogen bonds. These intramolecular interactions and the extensive base stacking in the loop help explain the high thermodynamic stability and give insight into the diverse biological roles of the GNRA RNA hairpins.

Monoclonal antibody MON-114: detection of a marker for neuroendocrine differentiation in human lung cancer.

Mouse monoclonal antibody MON-114 was generated upon immunization with a human small cell lung carcinoma cell line GLC-19. Immunohistochemical analysis of normal tissues with MON-114 showed staining of the adrenal gland, brain and peripheral nerves. With respect to human lung carcinomas, 7 out of 8 small cell lung carcinomas were positively stained as well as 5 out of 5 carcinoid tumors, whereas only 4 out of 31 squamous cell carcinomas and 3 out of 19 adenocarcinomas were weakly stained. Furthermore, 1 large cell carcinoma was negative for MON-114 staining. Apparently, MON-114 stains cells of neuroendocrine differentiation.