TX Q&A

The essence of a single-arm target value design is to compare the results of the primary evaluation indicators with existing clinical data to assess the effectiveness/safety of the trial device. Compared to parallel controlled trials, single-arm trials inherently suffer from asynchronous control biases, which may lead to selection bias, confounding bias, measurement bias, and evaluation bias. Since no control group is set up, clinical trials using a single-arm target value design cannot confirm the superiority, equivalence, or non-inferiority of the trial device but can only verify that the effectiveness/safety of the trial device meets the recognized minimum standards in the field. A single-arm target value design may be considered when the device technology is mature and there is a deep understanding of the applicable diseases, or when setting up a control is objectively unfeasible (for example, if the risk-benefit ratio of the trial device compared to existing treatments is too disparate making a control ethically unfeasible; or if existing treatments are not feasible due to objective conditions). Given the technical development and current clinical application of intracranial drug-coated balloon dilatation catheters, they do not meet the basic principles for a single-arm target value design. It is recommended to choose a randomized controlled trial (RCT) design for clinical trials.

Enterprise reference materials are an important tool for product design, development, and quality control. It is recommended that when preparing enterprise reference materials, clinical samples should be used as a priority. For very rare samples, alternative samples such as pathogen cultures or cell lines may be considered. The specific choice should comply with the guidelines relevant to the product in question.

Based on the current level of understanding, surgical instrument products that are made entirely of metal materials and have been validated to meet the national, industry, and international standards for metallic materials used in surgical implants or surgical instruments, as well as the material grades specified in relevant national and industry standards (such as the material grade specified in YY/T 0176 "General Technical Conditions for Medical Scissors"), can be exempt from biological testing. This exemption is possible provided that documentation validating the chemical composition of the materials is provided (if it can be demonstrated that the manufacturing process does not affect the chemical composition of the materials, submission in the form of a raw material specification sheet may be acceptable).

The device characteristics related to the structural design of implant products should include: 1) Implant shape design; 2) Macro design parameters of threads such as single-thread, double-thread, triple-thread, and geometric parameters of thread units (thread shapes like V-shaped, rectangular, serrated, biased trapezoidal, reverse biased trapezoidal, square, etc.), thread pitch, and thread depth; 3) Features of the implant neck (such as bone level, soft tissue level); 4) Design of the implant apex contour (such as blunt, sharp, cylindrical, conical) and the apex thread apex angle (such as symmetrical, top flat bottom inclined, top inclined bottom flat); 5) Implant-abutment connection types (such as internal hex connection, external octagon connection, Morse taper connection); 6) Axial plane characteristics of the implant (such as axial anti-rotation grooves); 7) Platform switching design (if applicable).

Changes in primary packaging require revalidation of sterilization and expiration dating, but generally, biological testing is not necessary.

The stability of in vitro diagnostic reagents refers to the ability to maintain their performance characteristics within the limits specified by the manufacturer. When conducting stability studies for reagents, it is important to consider variables that might affect the performance or efficacy of the reagents, including changes in environmental factors and the worst-case scenario. During the study, reagents should be stored under conditions specified by the manufacturer, which are set based on the capabilities of the testing equipment or the expected storage conditions of the product. These conditions should adequately validate the product's stability under the most adverse conditions. The results of the study should demonstrate that the product meets the stability requirements within the claimed storage conditions and duration. It is recommended that applicants clearly specify the range of storage conditions in their research documentation and stability claims, such as "store at 2~8°C," and avoid using ambiguous terms like "refrigerated," "frozen," or "room temperature" to describe storage temperatures.

Outsourced syringe components used in sodium hyaluronate products for injection, as part of the product, should have relevant performance specifications established and tested.

All-suture anchors can be clinically evaluated by comparing them with similar types of devices that have already been approved for market in the same region and have the same scope of application. The comparison with similar medical devices should include design principles, structural composition, size specifications, operational performance, and mechanical properties. The comparison of structural dimensions should include both the dimensions in the natural state and after the soft anchor contracts, identifying differences such as the weaving method and the thickness of the individual strands. For any differences in structural dimensions, it is necessary to explain why this design was chosen for the product being registered and to demonstrate that these differences do not adversely affect the product's safety and effectiveness. Operational performance comparisons should include insertion force and whether the soft anchor is prone to knotting. For non-quantitative operational performance indicators, if product design validation data demonstrate that it meets clinical needs, there may be no need to compare with similar products. Mechanical performance comparisons should include both dynamic and static fixation performance, and the mechanical performance of the product being registered should not be inferior to that of similar products. When comparing mechanical performance with similar devices, attention should be paid to the appropriateness of test parameters (such as load size and cycle count) and the selection of mechanical test fixtures. If using artificial bone, it is recommended to determine the composition, thickness, and density of the simulation blocks (such as cortical/trabecular bone composite blocks) based on the bone quality conditions in clinical use, and ensure that the test drilling diameter is consistent with the diameter used clinically. When providing mechanical test reports, it is important to clearly define the failure modes of each sample. For anchors expected to be used in anatomical sites with significantly different biomechanical requirements, comparisons should be made separately with anchors that have the same range of applicability.

Fiber posts, made from fiber fillers and resin composites, are devices implanted into root canals and carry a high risk. Their performance is greatly affected by environmental temperature, so it is recommended to establish a shelf life and provide relevant shelf life study data.

For the software part of this module, you can follow the relevant requirements for off-the-shelf software as specified in the "Guidance on the Review of Medical Device Software Registration (2022 Revised Edition)" and provide the necessary off-the-shelf software documentation.