DYRK1A

研发进展推介、博士后招聘联系公众号（备注：单位+姓名） 2024年3月18日，李志裕教授等人在Journal of Medicinal Chemistry 上发表了题为Structure-Guided Discovery of Potent and Selective CLK2 Inhibitors for the Treatment of Knee Osteoarthritis的文章，在这篇文章中，作者等人设计并合成了一系列高效的基于吲唑类化合物的CLK2抑制剂，其中化合物LQ23对CLK2的抑制活性高于先导化合物(IC50=1.4 nM)，具有较高的CLK2/CLK3选择性(>70倍)。此外，LQ23在体内外均有显著的抗骨关节炎作用，其作用机制可能是通过抑制CLK2/Wnt信号通路，降低炎症细胞因子，下调软骨降解酶，增加关节软骨。总体而言，这些数据支持LQ23作为膝关节内OA治疗的潜在候选者，利用其独特的作用机制进行靶向治疗。骨关节炎是一种典型的退行性疾病，传统上具有不同的病因，但具有相似的生物学、形态学和临床特征。在各种类型的骨性关节炎中，膝关节骨性关节炎的发病率尤其高。骨性关节炎的疼痛和残疾严重影响患者的生活质量，已成为当今社会严重的社会和经济负担之一。目前，骨性关节炎的治疗相对有限，主要集中在抗炎药物上。然而，消炎药并不能修复软骨。因此，对治疗疾病的骨性关节炎药物(DMOADs)的需求尚未得到满足。DMOADs不仅具有抗炎作用，还可通过促进软骨细胞再生和抑制软骨分解代谢来减轻软骨损伤。研究表明Wnt信号在骨性关节炎发病机制中的核心作用，许多与Wnt途径相关的新的生物学过程和靶点已被发现。在这些靶点中，酪氨酸和丝氨酸/苏氨酸激酶CLKs被报道通过调节细胞内信号来调节Wnt途径。基于CLK2在退行性疾病和肿瘤中的重要作用，研究机构相继设计了许多不同类型的CLK2抑制剂。目前，有五种药物正在进行临床试验，用于治疗退行性疾病和肿瘤。2018年，J.Kallen的团队报告了一系列有效的吲唑类CLK抑制剂的发现。确定了吲唑1是一种高效的吲唑CLK抑制剂，作为先导化合物。随后，作者等人引入了芳香族乙炔基团，合成了一系列新型的CLK2抑制剂。在这些抑制剂中，LQ23(CLK2，IC50=1.4 nM)表现出显著的CLK2抑制活性。并且LQ23对CLK1/2/4(CLK1，IC50=2.1 nM；CLK2，IC50=1.4 nM；CLK4，IC50=3.2 nM)显示出更高的抑制效力。此外，LQ23对CLK2的选择性高于CLK3(IC50>100 nm)。随后作者等人进一步证实LQ23对蛋白激酶的选择性，结果表明化合物LQ23是一种很好的选择性CLK2抑制剂。（图1）图1 (A)化合物LQ23对CLK2、CLK3和DYRK1A的抑制活性。(B) pSRSF4、pSRSF5和pSRSF6在二甲亚砜(DMSO)或Lorecivivint (30 nM)或LQ23(10、30和100 nM)处理1小时后的蛋白表达情况。(C) pSRSF4、pSRSF5和pSRSF6在转染靶向CLK2的siRNA的软骨细胞中的蛋白表达情况接下来，作者等人评估了LQ23在体外诱导软骨细胞早期分化的能力。据报道，转化生长因子β3可刺激骨髓间充质干细胞分化为高度特异的软骨细胞。结果表明LQ23可诱导骨髓间充质干细胞分化为软骨细胞样细胞(图2A)。此外，在单层条件下用LQ23处理14天的BMSCs表明软骨细胞正在分化，这是由成熟软骨细胞特异性蛋白(II型胶原，Col IIA)的存在支持的(图2B)。提示LQ23可促进BMSCs向软骨细胞分化。图2 LQ23诱导骨髓间充质干细胞的软骨细胞分化。(A)骨髓间质干细胞(用30 nM LQ23或DMSO或20 ng/mL TGF β3处理14天)用甲苯胺蓝和阿利新蓝染色。(B)骨髓间充质干细胞(用30 nM LQ23或DMSO或20 ng/mL TGF β3处理14天)用Col IIA染色，显示成熟软骨细胞除促进软骨再生外，骨性关节炎的长期疾病治疗还需要抑制软骨的降解。因此，作者等人还评估了LQ23对软骨细胞和骨髓间充质干细胞在病理生理条件下的分解代谢的影响。当肿瘤坏死因子TNF-α(20 ng/m L)和肿瘤抑素M(OM，10 ng/m L)处理时，软骨细胞和骨髓间充质干细胞MMP3、MMP13和ADAMTS5的基因表达上调(图3A，B)。LQ23(30 NM)可显著抑制细胞因子诱导的基质降解酶的表达，包括MMP3、MMP13和ADAMTS5(图3A，B)，其效力与Lorecivivint(30 nM)相似或提高。LQ23治疗组与模型组比较，NO释放量明显减少。提示LQ23在体外对软骨降解有抑制作用。图3 LQ23保护软骨细胞和骨髓间充质干细胞免受体外分解代谢破坏。细胞因子TNF-α (20 ng/mL)和Oncostatin M (10 ng/mL)刺激软骨细胞和骨髓间充质干细胞，DMSO或Lorecivivint (30 nM)或LQ23 (30 nM)处理72 h如图4所示，LQ23和Lorecivivint均能有效抑制肿瘤坏死因子TNF-α、IL-6和IL-β在TNF-α和OM刺激的软骨细胞中的表达。同时，LQ23的抑制作用与siCLK2一致。体外实验表明，LQ23具有与Lorecivivint相当的抗炎活性。随后，在TNF-α和OM刺激的软骨细胞中，观察了LQ23对STAT3的影响。当用TNF-α和OM处理软骨细胞时，Western Blot检测到STAT3的磷酸化水平显著升高(图5)，而LQ23则呈剂量依赖性地抑制STAT3的磷酸化。提示LQ23具有较强的体外抗炎作用。图4 LQ23抑制软骨细胞的炎症反应。用细胞因子TNF-α (20 ng/mL)和Oncostatin M (10 ng/mL)刺激软骨细胞，用DMSO或Lorecivivint (30 nM)或LQ23 (30 nM)处理48 h。用qRT-PCR检测细胞因子(TNF-α、IL-6和IL-1β)的基因表达图5 LQ23剂量依赖性地抑制TNF-α和OM刺激的软骨细胞中STAT3磷酸化。(A) Western blot检测TNF-α和OM刺激软骨细胞中磷酸化和总STAT3蛋白表达水平。(B)通过三次独立实验定量测定pSTAT3和STAT3的比例半月板损伤常见于膝关节骨性关节炎的MRI图像，可导致膝关节骨性关节炎。然而，修复半月板损伤的努力在很大程度上并不成功，也未能阻止导致膝关节骨性关节炎的退行性改变的进展。在大鼠炎性半月板损伤模型和大鼠前交叉韧带切断内侧半月板部分切除(ACLT+pMMx)模型上，采用生化和组织病理学方法观察LQ23对软骨再生和保护的影响。MIA可引起局部炎症、软骨退变和关节疼痛增加，或LQ23(1.5μg/kg，单次IA注射)可降低血浆中炎症细胞因子(TNF-α、IL-6和IL-1β)水平和软骨中分解代谢酶(MMP3、MMP13和ADAMTS5)水平。此外，与OA疾病严重程度相关的循环COMP水平在LQ23治疗的大鼠中自治疗后第11天起显著降低。LQ23在治疗后28天仍有效(图6A，B)。第28天苏木精-伊红(H&E)染色显示，LQ23治疗组关节形态明显改善。经LQ23治疗后，关节软骨表面光滑，细胞排列更规则，滑膜厚度减少，股骨与胫骨间隙增大(图6C)。而Lorecivivint或LQ23治疗显著降低了光镜下软骨检测评价标准OARSI评分51(图6D)，提示LQ23抑制炎症，保护软骨。图6 LQ23在碘乙酸钠(MIA)诱导的大鼠膝关节OA模型中抑制炎症，保护软骨，改善功能。注射mia的大鼠经IA注射给药后，分别给药整车或Lorecivivint (1.5μg/kg)或LQ23 (1.5μg/kg)。软骨和血浆分别于第11天和第28天采集综上所述， CLK2是开发DMOAD药物的一个与Wnt途径相关的有前景的靶点。作者团队发现了一系列新的化合物，确定了具有代表性的化合物LQ23，该化合物对CLK2具有较强的抑制活性，IC50为1.4 nM，且比CLK3具有更高的选择性。LQ23还可诱导BMSCs向软骨细胞分化。在体外，LQ23还能降低细胞因子诱导的NO生成和体内循环COMP水平，这表明LQ23可以预防OA病理条件下的基质分解。体内药代动力学数据和受试化合物在体外人体细胞中的有效性证明了LQ23的药物设计理论是合理的。这些发现强调了LQ23作为一种小分子潜在的DMOAD的前景，用于膝骨性关节炎的有效治疗。原文链接：https://doi.org/10.1021/acs.jmedchem.3c02092声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！长按关注本公众号   粉丝群/投稿/授权/广告等请联系公众号助手 觉得本文好看，请点这里↓

Cash and cash equivalents of approximately $11.5 million as of October 31, 2023 Special meeting of stockholders on November 16 seeking stockholder approval of the Dissolution and Plan of Dissolution If approved by stockholders, the Company estimates that cash distributions in the Dissolution will be between $5 million and $7 million, or $0.84 to $1.17 per share, to stockholders BOULDER, Colo., Nov. 13, 2023 (GLOBE NEWSWIRE) -- Fresh Tracks Therapeutics, Inc. (the “Company” or “Fresh Tracks”) (Nasdaq: FRTX), today announced financial results for the third quarter ended September 30, 2023 and provided a corporate update. “Following the approval by our Board of a plan of liquidation and dissolution of the Company, we have taken numerous actions over the last few weeks to reduce operating expenses and conserve capital, with the primary goal of maximizing the remaining cash available to distribute to stockholders if the dissolution is approved,” commented Albert (Bert) N. Marchio, II, Fresh Tracks’ Chief Executive Officer, Chief Financial Officer, and director and Chairman of the Board. “As we move towards the special meeting of stockholders next week, we urge all stockholders to review the definitive proxy statement we filed with the SEC on October 20, 2023 and encourage them to vote as soon as possible. If the dissolution is approved at the special meeting, we intend to promptly file a Certificate of Dissolution with the Secretary of the State of Delaware and subsequently initiate the first of several liquidating cash distributions to stockholders.” Recent Corporate Highlights On September 19, 2023, Fresh Tracks announced a proposed plan of liquidation and dissolution (the “Plan of Dissolution”) and its intent to discontinue all clinical and preclinical development programs and reduce the Company’s workforce. Historically, Fresh Tracks was a clinical-stage pharmaceutical company striving to transform patient lives through the development of innovative and differentiated prescription therapeutics. The Company’s pipeline aimed to disrupt existing treatment paradigms and featured several new chemical entities that inhibit novel targets with first-in-class potential for autoimmune, inflammatory, and other debilitating diseases. The Company’s board of directors (“Board”) and executive management team conducted a comprehensive process to explore and evaluate strategic alternatives with the goal of maximizing stockholder value. Potential alternatives that were under evaluation included, but were not limited to, a financing, a merger or reverse merger, the sale of all or part of the Company, licensing of assets, a business combination, and/or other strategic transactions or series of related transactions involving the Company. On September 18, 2023, after conducting an extensive, months-long potential strategic alternatives process, including four unsuccessful attempts to find a merger or reverse merger partner due to the potential acquirer’s inability to secure its own necessary financing and/or inability to offer adequate value to consummate the transaction, and combined with the unsuccessful outreach to approximately 125 other possible counterparties and investors who operate or invest in both life sciences and other industry sectors, the Board unanimously approved the Company’s proposed liquidation and dissolution (the “Dissolution”) and the Plan of Dissolution, subject to the approval of the Company’s stockholders. In connection with the Plan of Dissolution, effective October 2, 2023, the Company discontinued all clinical and preclinical development programs and terminated most of its employees, except for certain employees, consultants, and advisors who will supervise or facilitate the dissolution and wind down of the Company, if approved by the Company’s stockholders. Fresh Tracks plans to hold a special meeting of stockholders on November 16, 2023 (the “Special Meeting”) to seek stockholder approval of the Dissolution and the Plan of Dissolution and has filed proxy materials relating to the Special Meeting with the Securities and Exchange Commission (“SEC”). If the Dissolution and the Plan of Dissolution are approved by the Company’s stockholders, based on currently available information, the Company estimates that it will have in the range between approximately $5.0 million and $7.0 million of cash available to be distributed to stockholders in connection with the Dissolution, which implies a per share distribution range of $0.84 to $1.17 per share of common stock. Distributions, if any, to the Company’s stockholders may be paid in one or more distributions over a period of several years. Such distributions will not occur until after the Certificate of Dissolution is filed, which the Company intends to do as soon as practicable after stockholder approval, if such approval is obtained. The Board of Directors fixed the close of business on October 17, 2023, as the record date for the Special Meeting. Only stockholders of record at the close of business on that date may vote at the Special Meeting or any adjournment thereof. Your vote is important. If you have questions about how to vote, please call the Company’s proxy solicitor D.F. King at 800-769-4414 (or international: 914-218-4628). Third Quarter 2023 Financial Results The Company reported cash and cash equivalents of $12.0 million as of September 30, 2023, compared to $8.7 million as of December 31, 2022. As of October 31, 2023, the Company’s cash balance was approximately $11.5 million. Revenue was $7.9 million for the third quarter of 2023, compared to $0.5 million for the third quarter of 2022. Revenue for the third quarter of 2023 primarily consisted of contract revenue of $7.9 million recognized pursuant to its Asset Purchase Agreement Amendment with Botanix SB Inc. (“Botanix”) and Botanix Pharmaceuticals Limited (the “Asset Purchase Agreement”), in which the Company agreed to terminate and relinquish any remaining amounts potentially payable by Botanix to the Company in the future. Revenue for the third quarter of 2022 primarily consisted of contract revenue recognized under the Asset Purchase Agreement and a Transition Services Agreement with Botanix. Research and development expenses were $0.6 million for the third quarter of 2023, compared to $3.6 million for the third quarter of 2022. The decrease was primarily driven by decreased expenses of $2.3 million related to the Company’s DYRK1A inhibitor program and $0.6 million for personnel and other unallocated expenses. General and administrative expenses were $5.3 million for the third quarter of 2023, compared to $3.0 million for the third quarter of 2022. The increase of $2.3 million was primarily the result of $1.7 million for a licensing fee to the Company’s former licensor in July 2023 under the Asset Purchase Agreement Amendment and $1.1 million in higher compensation-related expenses primarily due to severance expense, partially offset by $0.5 million in lower legal and compliance fees. The Company reported net income of $2.1 million for the third quarter of 2023 compared to a net loss of $6.0 million for the third quarter of 2022. IMPORTANT ADDITIONAL INFORMATION AND WHERE TO FIND IT This press release is for informational purposes only. It is neither a solicitation of a proxy, an offer to purchase, nor a solicitation of an offer to sell shares of the Company. In connection with the proposed Dissolution and the Plan of Dissolution, the Company filed a definitive proxy statement with the SEC on October 20, 2023. BEFORE MAKING ANY VOTING DECISION, INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE DEFINITIVE PROXY STATEMENT, ANY AMENDMENTS OR SUPPLEMENTS THERETO, ANY OTHER SOLICITING MATERIALS AND ANY OTHER DOCUMENTS TO BE FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED DISSOLUTION, THE PLAN OF DISSOLUTION AND RELATED MATTERS, AND/OR INCORPORATED BY REFERENCE IN THE PROXY STATEMENT WHEN THEY BECOME AVAILABLE BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION ABOUT FRESH TRACKS, THE PROPOSED DISSOLUTION, THE PLAN OF DISSOLUTION AND RELATED MATTERS. Stockholders may obtain a free copy of the definitive proxy statement and the other relevant materials, and any other documents filed by the Company with the SEC, at the SEC's website at http://www.sec.gov or on the “Investors” section of Fresh Track’s website at www.frtx.com. Participants in the Solicitation Fresh Tracks and its executive officers and directors may be deemed to be participants in the solicitation of proxies from its stockholders with respect to the proposed Dissolution, the Plan of Dissolution and related matters, and any other matters to be voted on at the Special Meeting. Information regarding the names, affiliations and direct or indirect interests, by security holdings or otherwise, of such directors and executive officers in the solicitation are included in the definitive proxy statement filed with the SEC on October 20, 2023. Additional information regarding such directors and executive officers, and other important Company information, are included in Fresh Track’s Annual Report on Form 10-K/A for the year ended December 31, 2022, which was filed with the SEC on May 1, 2023. Information regarding the persons who may, under SEC rules, be deemed participants in the solicitation of proxies of Fresh Track’s stockholders in connection with the proposed Dissolution, the Plan of Dissolution and related matters are set forth in the definitive proxy statement. These documents are available free of charge as described in the preceding section. For more information, visit https://www.frtx.com. Cautionary Note Regarding Forward-Looking Statements Any statements made in this press release relating to future financial, business, conditions, plans, prospects, impacts, shifts, trends, progress, or strategies and other such matters, including without limitation, Fresh Tracks’ proposed Dissolution pursuant to its Plan of Dissolution, the timing of filing of the Certificate of Dissolution, the timing and outcome of the Special Meeting to approve the Dissolution and the Plan of Dissolution, the amount, number, and timing of liquidating distributions, if any, to its stockholders, the amount of reserves, and similar statements, are forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995. In addition, when or if used in this press release, the words “may,” “could,” “should,” “might,” “show,” “continue,” “conduct,” “report,” “seek,” “report,” “conserve,” “distribute,” “dissolve,” “encourage,” “discontinue,” “terminate,” “wind down,” “additional,” “announce,” “anticipate,” “believe,” “sufficient,” “estimate,” “expect,” “intend,” “plan,” “potential,” “will,” “evaluate,” “aim,” “meet,” “support,” “look forward,” “develop,” “promise,” “provide,” “first-in-class,” “opportunity,” “disrupt,” “reduce,” “suggest,” and similar expressions and their variants, as they relate to Fresh Tracks or any of Fresh Tracks’ partners, or third parties, may identify forward-looking statements. Fresh Tracks cautions that these forward-looking statements are subject to numerous assumptions, risks, and uncertainties, which change over time, often quickly, and in unanticipated ways. Important factors that may cause actual results to differ materially from the results discussed in the forward-looking statements or historical experience include the availability, timing and amount of liquidating distributions being different than expected; the amounts that will need to be set aside as reserves by Fresh Tracks being higher than anticipated; the possible inadequacy of such reserves to satisfy Fresh Tracks’ obligations; potential unknown contingencies or liabilities, and Fresh Tracks’ potential inability to favorably resolve them or at all; the amount of proceeds that might be realized from the sale or other disposition of any remaining Fresh Tracks assets; the application of, and any changes in, applicable tax and other laws, regulations, administrative practices, principles and interpretations; the incurrence by Fresh Tracks of expenses relating to the Dissolution being different than estimated; the ability of the Fresh Tracks board of directors to abandon, modify or delay implementation of the Dissolution, even after stockholder approval; failure of the Company’s stockholders to approve the proposed Plan of Dissolution; the Company’s ability to settle, make reasonable provision for or otherwise resolve its liabilities and obligations, including the establishment of an adequate contingency reserve; and the uncertain macroeconomic and political environment. Further information on the factors and risks that could cause actual results to differ from any forward-looking statements are contained in Fresh Tracks’ filings with the SEC, which are available at https://www.sec.gov (or at https://www.frtx.com). The forward-looking statements represent the estimates of Fresh Tracks as of the date hereof only. Fresh Tracks specifically disclaims any duty or obligation to update forward-looking statements. Fresh Tracks Therapeutics, Inc.Investor Contact:Dan FerryLifeSci Advisors(617) 430-7576daniel@lifesciadvisors.com Fresh Tracks Therapeutics, Inc.Condensed Consolidated Statements of Operations(in thousands, except share and per share data)(unaudited) Three Months EndedSeptember 30, Nine Months EndedSeptember 30, 2023 2022 2023 2022 Revenue Contract revenue$7,944 $486 $8,006 $4,801 Royalty revenue — — — 92 Total revenue 7,944 486 8,006 4,893 Operating expenses: Research and development 627 3,560 3,172 11,438 General and administrative 5,320 3,002 9,542 10,396 Total operating expenses 5,947 6,562 12,714 21,834 Income (loss) from operations 1,997 (6,076) (4,708) (16,941)Other income 107 58 257 372 Interest expense — — (5) (6)Net income (loss) 2,104 (6,018) (4,456) (16,575)Less: net income attributable to participating securities (197) — — — Net income (loss) attributable to common stockholders$1,907 $(6,018) $(4,456) $(16,575) Net income (loss) per common share attributable to common stockholders, basic and diluted$0.32 $(2.07) $(0.86) $(6.05)Weighted-average shares used to compute net income (loss) per share attributable to common stockholders, basic and diluted 5,912,786 2,906,000 5,199,856 2,738,954 Fresh Tracks Therapeutics, Inc.Selected Financial InformationCondensed Consolidated Balance Sheet Data(amounts in thousands)(unaudited) September 30,2023 December 31,2022Cash and cash equivalents$12,020 $8,680Prepaid expenses and other current assets 993 1,403Total assets 13,057 10,271Total liabilities 2,108 3,077Total stockholders’ equity 10,949 7,194

Pictured: Closed sign being flipped over/iStock, StockSeller_ukr Colorado-based pharma Fresh Tracks announced Tuesday that its board of directors had unanimously agreed to dissolve the company and liquidate its assets, while California biotech Histogen on Monday also announced that it was dissolving and liquidating its business. Fresh Tracks will discontinue all its clinical and preclinical development programs as well as lay off “most employees,” which is set to happen by early October 2023, according to the company’s announcement. The news comes after the company’s search for potential strategic alternatives to save its business had turned up empty. However, Fresh Tracks will retain consultants, advisors and certain employees who are involved in the company’s dissolution. The company’s liquidation is still pending final approval from its shareholders. A day before Fresh Tracks announced its closure plans, San Diego-based Histogen said that it was dissolving and liquidating its business. Like its Colorado counterpart, Histogen has opted to discontinue all clinical development programs and has drastically slimmed down its workforce as part of its dissolution plan. Most employees will be laid off by the end of September 2023, according to the company’s announcement. Fresh Tracks was launched in September 2022 from a sweeping rebranding of Brickell Biotech. At the time, former CEO Robert Brown said that the company’s new name reflects the company’s mission “to develop groundbreaking, novel therapies that have the potential to restore immune balance.” Brown retired in January 2023 and was succeeded by Andew Sklawer. The company has since advanced a pipeline of immunology assets, including the DYRK1A inhibitor FRTX-02, which was in Phase I assessments for atopic dermatitis and was also being proposed for rheumatoid arthritis and type 1 diabetes. The company also owned an oral STING inhibitor, dubbed FRTX-10, which was in preclinical development for systemic lupus erythematosus, dermatomyositis and non-alcoholic steatohepatitis. In its most recent earnings report, posted August 2023, Fresh Tracks announced that it had “paused substantially all of its research and development activities in order to conserve capital resources.” In a previous earnings call soon after its rebrand, the company indicated that it was looking at strategic options including financing, merger or reverse merger, business combination or the sale of part of the company. Under its plan of dissolution, Histogen is considering selling off its pipeline assets—the proceeds from which would be distributed to stockholders along with its remaining cash. The proposed dissolution is still pending approval from the company’s stockholders, for which it expects to convene a special meeting in the fourth quarter of this year. Prior to the announcement, Histogen was advancing its experimental bacterial skin infection treatment emricasan. It had received the FDA’s go-ahead in March 2023 to conduct clinical trials for the candidate. Tristan Manalac is an independent science writer based in Metro Manila, Philippines. He can be reached at tristan@tristanmanalac.com or tristan.manalac@biospace.com.