PPTC7 antagonizes mitophagy by promoting BNIP3 and NIX degradation via SCFFBXL4.

Mitophagy must be carefully regulated to ensure that cells maintain appropriate numbers of functional mitochondria. The SCFFBXL4 ubiquitin ligase complex suppresses mitophagy by controlling the degradation of BNIP3 and NIX mitophagy receptors, and FBXL4 mutations result in mitochondrial disease as a consequence of elevated mitophagy. Here, we reveal that the mitochondrial phosphatase PPTC7 is an essential cofactor for SCFFBXL4-mediated destruction of BNIP3 and NIX, suppressing both steady-state and induced mitophagy. Disruption of the phosphatase activity of PPTC7 does not influence BNIP3 and NIX turnover. Rather, a pool of PPTC7 on the mitochondrial outer membrane acts as an adaptor linking BNIP3 and NIX to FBXL4, facilitating the turnover of these mitophagy receptors. PPTC7 accumulates on the outer mitochondrial membrane in response to mitophagy induction or the absence of FBXL4, suggesting a homoeostatic feedback mechanism that attenuates high levels of mitophagy. We mapped critical residues required for PPTC7-BNIP3/NIX and PPTC7-FBXL4 interactions and their disruption interferes with both BNIP3/NIX degradation and mitophagy suppression. Collectively, these findings delineate a complex regulatory mechanism that restricts BNIP3/NIX-induced mitophagy.

Patent Portfolios Protecting 10 Top-Selling Prescription Drugs.

Importance: Brand-name drugs are sold at high prices in the US during market exclusivity periods protected by patents. Multiple overlapping patents protecting a drug are known as patent thickets and can effectively delay the emergence of price-lowering generic competition for many years. Objective: To evaluate the composition of patent thickets of 10 top-selling prescription drugs in the US and compare the characteristics of drug patents filed during development with those filed on these products after US Food and Drug Administration (FDA) approval. Design and Setting: This cross-sectional study examined US patent thickets of the 10 prescription drugs with the highest US net sales revenue in 2021 using information on issued patents and patent applications as of June 30, 2022, obtained from a public database by the Initiative for Medicines, Access, and Knowledge. Data were analyzed from September 2022 to June 2023. Main Outcomes and Measures: Prevalence of patents filed before and after FDA approval; types of claims present in issued patents (ie, chemical composition, method of use, process or synthesis, formulation, and delivery device); and patent thicket density (number of active patents at a given time). Results: The 10 top-selling prescription drugs in the US for 2021 included 4 small-molecule drugs and 6 biologics. These 10 drugs were linked to 1429 patents and patent applications: 742 (52%) issued patents, 218 (15%) pending applications, and 469 (33%) abandoned applications. Almost three-quarters of patent applications (1028 [72%]) were filed after FDA approval. The postapproval proportion was higher for biologics (80%) than for small-molecule drugs (58%). Postapproval filing of patent applications peaked in the first 5 years after FDA approval for small-molecule drugs and 12 years after FDA approval for biologics. Of 465 patents issued for applications filed after FDA approval, 189 (41%) had method of use claims, 127 (27%) had formulation claims, and 103 (22%) had process or synthesis claims, while 86 (19%) had chemical composition claims and 46 (10%) had device claims. Patent thicket density peaked 13 years after FDA approval, at which time these 10 drugs were protected by a median (IQR) of 42 (18-83) active patents, 66% of which were filed after FDA approval. Conclusions and Relevance: This study found that among the 10 top-selling prescription drugs in the US in 2021, patents filed after FDA approval and containing claims covering aspects other than the active ingredient of the drug contributed to patent thickets. Scrutiny of patent applications and of patents filed after FDA approval is needed to facilitate timely generic or biosimilar competition.

Mitochondrial fusion and altered beta-oxidation drive muscle wasting in a Drosophila cachexia model.

Cancer cachexia is a tumour-induced wasting syndrome, characterised by extreme loss of skeletal muscle. Defective mitochondria can contribute to muscle wasting; however, the underlying mechanisms remain unclear. Using a Drosophila larval model of cancer cachexia, we observed enlarged and dysfunctional muscle mitochondria. Morphological changes were accompanied by upregulation of beta-oxidation proteins and depletion of muscle glycogen and lipid stores. Muscle lipid stores were also decreased in Colon-26 adenocarcinoma mouse muscle samples, and expression of the beta-oxidation gene CPT1A was negatively associated with muscle quality in cachectic patients. Mechanistically, mitochondrial defects result from reduced muscle insulin signalling, downstream of tumour-secreted insulin growth factor binding protein (IGFBP) homologue ImpL2. Strikingly, muscle-specific inhibition of Forkhead box O (FOXO), mitochondrial fusion, or beta-oxidation in tumour-bearing animals preserved muscle integrity. Finally, dietary supplementation with nicotinamide or lipids, improved muscle health in tumour-bearing animals. Overall, our work demonstrates that muscle FOXO, mitochondria dynamics/beta-oxidation and lipid utilisation are key regulators of muscle wasting in cancer cachexia.

Delivery Device Patents on GLP-1 Receptor Agonists.

This study analyzed the US Food and Drug Administration­listed patents on glucagon-like peptide 1 (GLP-1) receptor agonists to determine their claim characteristics and the potential barriers they pose to generic entry.

Patents on Risk Evaluation and Mitigation Strategies for Prescription Drugs and Generic Competition.

This cross-sectional study identifies the prevalence of patents on risk evaluation and mitigation strategies and their association with delaying generic competition.

Accurate Plane Fat Grafting in Gluteal Augmentation: An Anatomic Study.

BACKGROUND: The safety of gluteal fat grafting is a global concern in plastic surgery. OBJECTIVE: The goal of this study was to test whether fat grafting to the buttocks with Auto Stop Reach (ASR) technology prevents penetration from the subcutaneous space into the fascia and muscle layers of the buttocks. METHODS: Fat transfer simulation was performed with blue dye on 8 fresh tissue cadaver buttocks by 3 board-certified plastic surgeons (S.S.K., S.C., B.W.). An open control was utilized to visualize the process in the different anatomic layers, and all of the other procedures were performed blindly, akin to live surgery. After blue dye transfer reached maximum capacity (ranging from 400-800 mL per buttock), dissection of the anatomical layers of the buttocks was performed to determine the plane(s) of injection. RESULTS: Blue dye fat transfer injection to the buttocks did not penetrate the gluteal fascia or muscle layers from the subcutaneous space while using ASR. CONCLUSIONS: Auto Stop Reach technology supports the safety of gluteal fat transfer in the subcutaneous space by board-certified plastic surgeons.

Biologic Patent Thickets and Terminal Disclaimers.

This study analyzes the use and timing of terminal disclaimers in all biologic patents involved in litigation from 2010 to 2023.

Preserving Timely Generic Drug Competition with Legislation on "Skinny Labeling".

Patents prevent generic drug entry. Brand firms file new "method of use" patents for old drugs to prevent generic entry. Congress addressed this issue by creating the "skinny label" pathway, which allows generic firms to use the drug label to indicate that the old drug can only be used for non-patented uses. This pathway is now in jeopardy due to a recent court case. This paper outlines the issues and suggests possible legislative solutions.

Ancillary Product Patents to Extend Biologic Patent Life.

This study examines all patents associated with biologic litigation to understand how manufacturers use ancillary product patents to delay biosimilar market entry.

Inequitable Conduct and Invalidation of Patents Related to Food and Drug Administration-Regulated Products.

This study examines the frequency of drug patent invalidations based on inequitable conduct.

Next-Generation Bioprinted Products: Products of Nature or Patentable Innovation?

Bioprinting is an additive manufacturing process used to create architectures that mimic natural living tissues in form and function [1]. It involves the deposition of bioink, which can include a mixture of living cells, nutrients, and extracellular matrix. The bioink is then deposited onto a scaffold to generate 3-D structures that imitate natural tissues and organs. This process has already been used to generate a diverse range of products, including bioprinted human ears for transplant, and 3-D printed bioceramic and modified biopolymer bone implants that received U.S. Food and Drug Administration (FDA) marketing approval [2] Researchers are working on bioprinted versions of a wide range of organs, including liver, kidney, lung, and heart.

Free Speech Challenges to the Inflation Reduction Act.

This Viewpoint looks at the lawsuits brought by pharmaceutical companies to challenge the Inflation Reduction Act of 2022, in particular claims under the First Amendment's protection of free speech.

Changes in the Number of Continuation Patents on Drugs Approved by the FDA.

This study assesses the frequency of continuation patents on brand-name drugs approved by the US Food and Drug Administration from 2000 to 2015.

Patents and Regulatory Exclusivities on GLP-1 Receptor Agonists.

Importance: Glucagon-like peptide 1 (GLP-1) receptor agonists were first approved for the treatment of type 2 diabetes in 2005. Demand for these drugs has increased rapidly in recent years, as indications have expanded, but they remain expensive. Objective: To analyze how manufacturers of brand-name GLP-1 receptor agonists have used the patent and regulatory systems to extend periods of market exclusivity. Evidence Review: The annual US Food and Drug Administration's (FDA) Approved Drug Products With Therapeutic Equivalence Evaluations was used to identify GLP-1 receptor agonists approved from 2005 to 2021 and to record patents and nonpatent statutory exclusivities listed for each product. Google Patents was used to extract additional data on patents, including whether each was obtained on the delivery device or another aspect of the product. The primary outcome was the duration of expected protection from generic competition, defined as the time elapsed from FDA approval until expiration of the last-to-expire patent or regulatory exclusivity. Findings: On the 10 GLP-1 receptor agonists included in the cohort, drug manufacturers listed with the FDA a median of 19.5 patents (IQR, 9.0-25.8) per product, including a median of 17 patents (IQR, 8.3-22.8) filed before FDA approval and 1.5 (IQR, 0-2.8) filed after FDA approval. Fifty-four percent of all patents listed on GLP-1 receptor agonists were on the delivery devices rather than active ingredients. Manufacturers augmented patent protection with a median of 2 regulatory exclusivities (IQR, 0-3) obtained at approval and 1 (IQR, 0.3-4.3) added after approval. The median total duration of expected protection after FDA approval, when accounting for both preapproval and postapproval patents and regulatory exclusivities, was 18.3 years (IQR, 16.0-19.4). No generic firm has successfully challenged patents on GLP-1 receptor agonists to gain FDA approval. Conclusions and Relevance: Patent and regulatory reform is needed to ensure timely generic entry of GLP-1 receptor agonists to the market.

FBXL4 suppresses mitophagy by restricting the accumulation of NIX and BNIP3 mitophagy receptors.

To maintain both mitochondrial quality and quantity, cells selectively remove damaged or excessive mitochondria through mitophagy, which is a specialised form of autophagy. Mitophagy is induced in response to diverse conditions, including hypoxia, cellular differentiation and mitochondrial damage. However, the mechanisms that govern the removal of specific dysfunctional mitochondria under steady-state conditions to fine-tune mitochondrial content are not well understood. Here, we report that SCFFBXL4 , an SKP1/CUL1/F-box protein ubiquitin ligase complex, localises to the mitochondrial outer membrane in unstressed cells and mediates the constitutive ubiquitylation and degradation of the mitophagy receptors NIX and BNIP3 to suppress basal levels of mitophagy. We demonstrate that the pathogenic variants of FBXL4 that cause encephalopathic mtDNA depletion syndrome (MTDPS13) do not efficiently interact with the core SCF ubiquitin ligase machinery or mediate the degradation of NIX and BNIP3. Thus, we reveal a molecular mechanism whereby FBXL4 actively suppresses mitophagy by preventing NIX and BNIP3 accumulation. We propose that the dysregulation of NIX and BNIP3 turnover causes excessive basal mitophagy in FBXL4-associated mtDNA depletion syndrome.

Five-Year Sales for Newly Marketed Prescription Drugs With and Without Initial Orphan Drug Act Designation.

This study evaluates sales revenue earned in the first 5 years for newly marketed brand-name drugs with and without an initial orphan drug designation.

Patent Challenges And Litigation On Inhalers For Asthma And COPD.

Between 1986 and 2020 the Food and Drug Administration (FDA) approved fifty-three brand-name inhalers for asthma and chronic obstructive pulmonary disease (COPD), but by the end of 2022 only three of those inhalers faced independent generic competition. Manufacturers of brand-name inhalers have created long periods of market exclusivity by obtaining multiple patents, many on the delivery devices rather than the active ingredients, and by introducing new devices that contain old active ingredients. Limited generic competition for inhalers has raised questions about whether the Drug Price Competition and Patent Term Restoration Act of 1984, also known as the Hatch-Waxman Act, for challenging patents is adequately facilitating the entry of complex generic drug-device combinations. For the fifty-three brand-name inhalers approved during the period 1986-2020, generic manufacturers filed challenges authorized by the Hatch-Waxman Act, which are known as paragraph IV certifications, on only seven products (13 percent). The median time from FDA approval to first paragraph IV certification was fourteen years. Paragraph IV certifications resulted in approved generics for only two products, each of which experienced fifteen years of market exclusivity before generic approval. Reform of the generic drug approval system is critical to ensuring the timely availability of competitive markets for generic drug-device combinations such as inhalers.

Regulated alternative splicing of Dscam2 is required for somatosensory circuit wiring.

Axon and dendrite placement and connectivity is guided by a wide range of secreted and surface molecules in the developing nervous system. Nevertheless, the extraordinary complexity of connections in the brain requires that this repertoire be further diversified to precisely and uniquely regulate cell-cell interactions. One important mechanism for molecular diversification is alternative splicing. Drosophila Down syndrome cell adhesion molecule (Dscam2) undergoes cell type-specific alternative splicing to produce two isoform-specific homophilic binding proteins. Regulated alternative splicing of Dscam2 is important for dendrite and axon patterning, but how this translates to circuit wiring and animal behavior is not well understood. Here, we examined the role of cell-type specific expression of Dscam2 isoforms in regulating synaptic partner selection in the larval somatosensory system. We found that synaptic partners in the nociceptive circuit express different Dscam2 isoforms. Forcing synaptic partners to express a common isoform resulted in nociceptive axon patterning defects and attenuated nocifensive behaviors, indicating that a role for Dscam2 alternative splicing is to ensure that synaptic partners do not express matching isoforms. These results point to a model in which regulated alternative splicing of Dscam2 across populations of neurons restricts connectivity to specific partners and prevents inappropriate synaptic connections.