作者: Wall, Rusty ; Zhu, Ying ; Hillier, Brian J ; Krakow, Jessica ; Chen, Tseng-Hui T ; Vinogradova, Maia ; Paolella, Bryce ; Hammel, Michal ; Pei, Rex ; Desmarais, Austin ; DuBridge, Robert ; Karunatilake, Chulani

ABSTRACT:

Background:

COBRA™ (COnditional Bispecific Redirected Activation) T-cell engagers are designed to target solid tumors as a single polypeptide chain prodrug that becomes activated by proteolysis in the tumor microenvironment. One COBRA molecule comprises seven Ig domains: three single-domain antibodies (sdAbs) recognizing a tumor target or human serum albumin (HSA), and CD3ε-binding variable fragment heavy chain (VH) and variable fragment light chain (VL) and their inactivated counterparts, VHi and VLi. Pairing of VH and VL, and VLi and VHi into single-chain variable fragments (Fv) is prevented by shortened inter-domain linkers. Instead, VH and VL are expected to interact with VLi and VHi, respectively, thus making a diabody whose binding to CD3ε on the T-cells is impaired.

Methods:

We analyzed the structure of an epidermal growth factor receptor (EGFR) COBRA in solution using negative stain electron microscopy (EM) and small-angle X-ray scattering (SAXS).

Results:

We found that this EGFR COBRA forms stable monomers with a very dynamic interdomain arrangement. At most, only five domains at a time appeared ordered, and only one VH-VL pair was found in the Fv orientation. Nonenzymatic posttranslational modifications suggest that the CDR3 loops in the VL-VHi pair are exposed but are buried in the VH-VLi pair. The MMP9 cleavage rate of the prodrug when bound to recombinant EGFR or HSA is not affected, indicating positioning of the MMP9-cleavable linker away from the EGFR and HSA binding sites.

Conclusion:

Here, we propose a model for EGFR COBRA where VH and VLi form an Fv, and VL and VHi do not, possibly interacting with other Ig domains. SAXS and MMP9 cleavage analyses suggest that all COBRA molecules tested have a similar structural architecture.

2018-09-01·Protein expression and purification

Antibody engineering to improve manufacturability

Article

作者: Wijesuriya, Sujeewa D ; Pongo, Elizabeth ; Tomic, Milan ; Farr-Jones, Shauna ; Garcia-Rodriquez, Consuelo ; Zhang, Fangjiu ; Marks, James D ; Horwitz, Arnold H ; Conrad, Fraser

Expression variation among antibodies produced by stably transfected Chinese Hamster Ovary (CHO) cells is well established. While developing CHO-K1 cell lines, we encountered a human monoclonal antibody, mAb B-c, with severe manufacturability issues, including very poor expression and high levels of heavy chain (HC) dimer and high molecular weight aggregates. Using transient expression in CHO-K1 cells, we identified light chain (LC) as the source of the manufacturability issues for this antibody. While other antibodies achieved optimal expression at 1:1 or 2:1 LC to HC ratios, mAb B-c required up to a 6:1 LC:HC for maximal expression, which was still significantly lower than that for other tested antibodies. To overcome the manufacturability issues, LC shuffling was performed with the original HC to select antibodies with unique LCs which retained acceptable binding affinities. Transient CHO-K1 expression evaluation of the new LCs co-expressed with the original HC identified antibodies with high expression at a 1:1 or 2:1 LC:HC; the expression levels of these new antibodies were comparable to those of other well-expressed antibodies. Expression of these new antibodies in stably transfected CHO-K1 cells confirmed these results. In addition, antibodies containing the new LCs had very low levels of high molecular weight aggregates and HC dimer. These results demonstrate that certain antibody manufacturability issues can be attributed to LC and that engineering antibodies by pairing HCs with alternate LCs can improve antibody expression and product quality while maintaining or improving affinity.

2018-01-01·MOLECULAR CANCER THERAPEUTICS

Caveolae-Mediated Endocytosis as a Novel Mechanism of Resistance to Trastuzumab Emtansine (T-DM1)

Article

作者: Hosselet, Christine ; Rosfjord, Edward ; Dushin, Russell ; Tylaska, Laurie ; Wang, Fang ; Zhou, Dahui ; Myers, Jeremy S. ; Loganzo, Frank ; Lu, Bingwen ; Sung, Matthew ; Gerber, Hans-Peter ; Golas, Jonathan ; Lucas, Judy ; Tan, Xingzhi ; King, Lindsay

Abstract:

Trastuzumab emtansine (T-DM1) is an antibody–drug conjugate (ADC) that has demonstrated clinical benefit for patients with HER2+ metastatic breast cancer; however, its clinical activity is limited by inherent or acquired drug resistance. The molecular mechanisms that drive clinical resistance to T-DM1, especially in HER2+ tumors, are not well understood. We used HER2+ cell lines to develop models of T-DM1 resistance using a cyclical dosing schema in which cells received T-DM1 in an “on-off” routine until a T-DM1–resistant population was generated. T-DM1–resistant N87 cells (N87-TM) were cross-resistant to a panel of trastuzumab-ADCs (T-ADCs) with non–cleavable-linked auristatins. N87-TM cells do not have a decrease in HER2 protein levels or an increase in drug transporter protein (e.g., MDR1) expression compared with parental N87 cells. Intriguingly, T-ADCs using auristatin payloads attached via an enzymatically cleavable linker overcome T-DM1 resistance in N87-TM cells. Importantly, N87-TM cells implanted into athymic mice formed T-DM1 refractory tumors that remain sensitive to T-ADCs with cleavable-linked auristatin payloads. Comparative proteomic profiling suggested enrichment in proteins that mediate caveolae formation and endocytosis in the N87-TM cells. Indeed, N87-TM cells internalize T-ADCs into intracellular caveolin-1 (CAV1)–positive puncta and alter their trafficking to the lysosome compared with N87 cells. T-DM1 colocalization into intracellular CAV1-positive puncta correlated with reduced response to T-DM1 in a panel of HER2+ cell lines. Together, these data suggest that caveolae-mediated endocytosis of T-DM1 may serve as a novel predictive biomarker for patient response to T-DM1. Mol Cancer Ther; 17(1); 243–53. ©2017 AACR.

项与 Maverick Therapeutics, Inc. 相关的新闻（医药）

2024-12-16

·vectorytx.com

VectorY Strengthens Leadership Team with appointment of Jim Scibetta as new CEO

Former CEO, Sander van Deventer to become President of R&D Lead program VTx-002 for Amyotrophic Lateral Sclerosis (ALS) advances into IND-enabling studies following favorable FDA feedback of pre-clinical package Expansion of corporate footprint into the US (Boston) Former CEO, Sander van Deventer to become President of R&D Lead program VTx-002 for Amyotrophic Lateral Sclerosis (ALS) advances into IND-enabling studies following favorable FDA feedback of pre-clinical package Expansion of corporate footprint into the US (Boston) Amsterdam, the Netherlands and Boston, MA, USA - December 16, 2024 - VectorY Therapeutics, a biotech company developing innovative vectorized antibody therapies for the treatment of neurodegenerative diseases, announces the appointment of Jim Scibetta as Chief Executive Officer. Former CEO and founder Sander van Deventer, will become President of R&D, and will continue to drive the development of VectorY’s pipeline including its lead program, VTx-002, a novel vectorized antibody targeting TDP-43 for the treatment of Amyotrophic Lateral Sclerosis (ALS), which is currently in IND-enabling studies. Concurrent with these activities, the Company has expanded its US presence by opening an office in Boston. Strengthening the Leadership team Mr. Scibetta brings more than 20 years of executive leadership experience, having built earlier stage companies focused on developing novel therapeutics for high unmet medical needs into mature biotechnology companies. Mr. Scibetta will also join the VectorY’s Board of Directors. Adam Rosenberg, Chairman of VectorY Therapeutics said: “On behalf of the Board, I’m delighted to welcome Jim as our new CEO. He brings a significant degree of experience, vision and leadership which will play a critical role at this juncture of VectorY’s development as we advance our lead program. Jim’s experience complements and will build on the great progress that Sander and the VectorY team have achieved over the past four years. He will drive the Company towards its upcoming milestones while expanding its presence in the US.” “I am excited about Jim joining the company as CEO. His experience of taking an innovative drug development pipeline and driving it forward is immensely valuable to VectorY as we approach the clinic,” added Sander van Deventer. “For VTx-002 in ALS, we recently received favorable FDA feedback regarding the sufficiency of our pre-clinical data package, our CMC requirements, and our proposed clinical protocol. It’s the perfect time for Jim to join and build out our team to facilitate rapid advancement of VTx-002 as well as the rest of our pipeline targeting neurodegenerative diseases”. “I am delighted to join VectorY at such a pivotal time," said Jim Scibetta. "VectorY has impressive early data behind its technology and preclinical programs, and the Company is supported by a leading investor syndicate. There is a clear path to achieving clinical data for its lead asset, VTx-002, with considerable future potential from the pipeline emanating from the novel VectorY platform.” He added: “VTx-002 was designed by Sander and his team based on a deep understanding of both the underlying pathological drivers of this devastating disease, and the advancements in science and therapeutic modalities specifically needed to attack those unique disease drivers. I look forward to working with and building on the talented team at VectorY to continue the advancement of this new treatment." Jim has served on numerous private and public company boards at value generating biotech companies, including CEO of Maverick Therapeutics leading to its 2021 acquisition by Takeda, President of Pacira BioSciences (Nasdaq: PCRX) during its growth from a clinical stage private company to a commercial stage public company worth more than $2 billion, and CFO of BioEnvision (Nasdaq: BIVN), having been instrumental in its sale to Genzyme. He recently served as a senior consultant to Rock Springs Capital, and has also served on the Boards and in executive positions at Matinas BioPharma, ImmuneID, and Aquestive Therapeutics. Prior to his biotech company-building career Mr. Scibetta spent 13 years in healthcare investment banking at Shattuck Hammond Partners and Paine Webber. He has an MBA from the University of Michigan. Advancing the pipeline and expanding the team VectorY is developing a new vectorized antibody treatment for ALS. The aim for the program, VTx-002, is to significantly delay disease progression and preserve quality of life in the majority of ALS patients by targeting the underlying TPD-43 pathology. VTx-002, currently in IND-enabling studies, selectively clears misfolded and aggregated TDP-43 from the cytoplasm of neuronal cells. Thereby, it restores the essential function of TDP-43 in the nucleus leading to preservation of neuronal cell function and health. The Company has recently received favorable FDA feedback regarding the sufficiency of the pre-clinical data package, CMC requirements, and the proposed clinical protocol. The aim is for the program to enter the clinic by the end of 2025. In November 2023, VectorY completed a $138 million Series A announced, co-led by EQT Life Sciences and Forbion via its Growth Opportunities Fund, to support clinical development of the Company’s lead program in ALS, and preclinical development of pipeline programs based on VectorY’s broad technology platform. The Company is headquartered in Amsterdam, the Netherlands, and recently opened an office in Boston. - Ends – Contacts VectorY Therapeutics B.V. Jim Scibetta, CEO Elena Ritsou, CCO E-mail: info@vectorytx.com Tel: +31 681 174 072 Vigo Consulting (Media) Melanie Toyne-Sewell / Rozi Morris VectorY@vigoconsulting.com Tel: +44 7890 022 814 About VectorY VectorY is on a mission to provide patients with neurodegenerative diseases a longer, better life by creating transformative vectorized antibody treatments. Our platform combines the promise of precise therapeutic antibodies with one-time AAV-based delivery to the CNS. Unique in-house expertise in antibodies, AAV vectors, protein degradation, manufacturing and neuroscience drives the rapid development of much needed disease-modifying therapies for neurodegenerative diseases such as ALS. For more information, see www.VectorYtx.com.

高管变更并购

2024-05-22

·BioPharmaDive

SixPeaks, a new obesity biotech, starts up with an option to sell to AstraZeneca

A new obesity drug developer from investment firm Versant Ventures is starting up with a deal to possibly sell itself to AstraZeneca.The startup, called SixPeaks Bio,launched Wednesday with $30 million in Series A funding led by Versant and involving AstraZeneca. Alongside the funding, the company also announced a collaboration that will see the British drugmaker provide up to $80 million in financing over the next two years. Over that time, AstraZeneca has an exclusive chance to buy SixPeaks at an agreed-upon price once the biotech is ready to bring its lead drug into human testing.SixPeaks is the product of Basel, Switzerland-based Ridgeline Discovery, one of a few initiatives Versant has hatched over the years to turn academic research into new companies. The company was formed to address what CEO Philip Larsen called a burgeoning problem for popular weight-loss drugs like Wegovy and Zepbound. While those medicines help people quickly shed pounds, lean muscle tissue is lost as well. That issue can be exacerbated by people starting and stopping treatment,which is likely to accelerate the unfavorable effect on body composition, he said.SixPeaks is one of a number of companies among them Regeneron,Biohaven Pharmaceuticaland startup BioAgefocused on preserving muscle mass. The company is making antibody drugs that, like some others in development,target so-called activin receptors, an approach thats shown the potential tomaintain muscle while cutting fat.SixPeaks said its drugs may be effective as monotherapies or alongside the incretin drugs that stimulate the gut hormones like GLP-1. Its also developing a conjugated medicine that combines both approaches, though none are yet in human testing.Larsen declined to share more specifics about SixPeaks' pipeline, but said the company has the “opportunity to reach quite broadly and not just focus on being the companion to GLP-1s.“The deal follows a strategy Versant once favored, in which it would create a startup alongside a prearranged acquisition deal with a specific buyer. These types of build-to-buy, or option deals were tools Versant and some other venture firms used to guarantee returns during a tough investment climate early last decade. But they come with trade-offs, locking a startup into a deal with potentially smaller financial upside than independent growth may offer. In some cases, an acquisition doesnt occur, forcing a young biotech to chart a new course.Versant has moved away from such arrangements since, but they've still been done in recent years, such as with Novartis' recent buyout of IFM Dueand Takedas acquisition of Maverick Therapeutics in 2021.According to Alex Mayweg, a managing director at Versant and chair of SixPeaks board, the company wrestled with which path to pursue after receiving early and intense interest from investors as well as pharmaceutical companies.We had options. This space is attracting a lot of attention, he said.But Larsen noted the huge costs associated with developing cardiovascular drugs, making it critical to execute a a clinical development plan with precision from the start, and getting a partnership fairly early.AstraZenecas drive, interest, capability and motivation to win in this race was extremely strong, Mayweg added.The British drugmaker aims to come from behind in that race,as its most advanced prospects are progressing towards mid-stage testing. But the company has circled cardiometabolic research as a key part of its goal to hit $80 billion in revenue by 2030, and last year, made its intentions clear by licensing an oral obesity drug from Chinese biotech Eccogene.In an investor presentation on Tuesday, AstraZeneca pointed to a number of potential drug combinations for its oral drug and a couple others in development. None of them, though, involved muscle preservation. '

并购

2024-02-02

·FierceBiotech

Takeda drops cancer candidates, axing immunocytokine and CAR-Ts amid shifting treatment landscape

Takeda’s pipeline cull affected assets outside of oncology. Takeda’s vision of becoming a leader in oncology ran into more trouble Thursday when the drugmaker axed (PDF) a midphase immunocytokine and three early-stage CAR-T cell therapy prospects from its R&D pipeline. Under CEO Christophe Weber, Takeda has worked to establish itself as a leader in oncology. But, as the executive said on a quarterly results call with investors, the company has “had some wins ... [and] some setbacks.” The results brought news of more setbacks, with Takeda using the update to reveal it has dropped a clutch of cancer candidates led by modakafusp alfa. Formerly known as TAK-573, modakafusp alfa consists of two interferon alpha-2b molecules fused to an anti-CD38 monoclonal antibody. The idea was to activate innate and adaptive immune cells—while also directly stopping the proliferation of multiple myeloma cells—through targeted interferon signaling. Takeda began a phase 1/2a Darzalex combination trial one year ago, adding to the slate of studies run in support of the immunocytokine, but has now pulled the plug on the program. Andrew Plump, M.D., Ph.D., president of R&D at Takeda, explained the decision on the conference call with investors. “This is a strategic decision based on a number of factors, including the existing data set, the rapidly evolving multiple myeloma treatment landscape and the long development timelines,” the R&D chief said. Takeda pushed modakafusp alfa out of the door as part of a pipeline clear-out that also hit three phase 1 autologous CAR-T candidates. Two of the prospects, GPC3-targeted TAK-102 and mesothelin-directed TAK-103, were in development in solid tumors. The third asset, TAK-940, was a CD19-directed, Memorial Sloan Kettering Cancer Center-partnered program that used the 1XX domain to try to enhance efficacy. While Takeda axed a clutch of cancer candidates, Plump said the company “remains committed to oncology and will continue to develop therapies across hematologic and solid tumors.” The R&D chief highlighted the SUMO inhibitor subasumstat, a pair of STING agonists and two T-cell engagers from the Maverick Therapeutics acquisition as candidates to watch. Plump also cited the appointment of PK Morrow, who joined Takeda from CRISPR Therapeutics last month, as a boost for the oncology unit. Morrow became head of the oncology therapeutic area unit at Takeda, having previously worked as chief medical officer of CRISPR, and held various roles at Amgen. Takeda’s pipeline cull also affected assets outside of oncology. The drugmaker removed three phase 2 drug candidates, namely the rare disease asset TAK-611—which flunked a trial last year—the Parkinson’s disease prospect TAK-071 and the depression molecule TAK-041. In phase 1, Takeda axed treatments for Alzheimer’s disease and nausea as well as a Zika vaccine candidate. Amid the changes, Takeda grew its R&D spend by 7.3%, although Chief Financial Officer Costa Saroukos said that “does reflect some phasing,” and the company is still aiming for a mid single digit increase over the full year. Saroukos made the comment on what looks set to be his last quarterly results conference call as CFO of Takeda. Milano Furuta, president of Takeda’s Japan pharma business unit, is preparing to take over as CFO in April. Saroukos is leaving because “after 20 years working abroad, I’m ready to move back to Australia to be closer to my family,” the outgoing CFO told investors.