Safety, Tolerability and Efficacy of AntiBKV as Treatment of BKV Infection in Kidney Transplant Recipients, a Randomized Phase II/III Study, Double-blind and Placebo-controlled

The purpose of this study is to evaluate the safety, tolerability, and efficacy of AntiBKV in reducing BKV DNAemia and progression to biopsy-confirmed BKVAN in kidney transplant recipients. This study has an operationally seamless phase II/III design. The phase II part will evaluate the safety of AntiBKV in kidney transplant recipients and establish antiviral proof of concept. The phase II part includes a dose-comparison part to generate additional PK and PD data of AntiBKV. The phase III part will assess the efficacy of AntiBKV in kidney transplant recipients. For both the phase II and phase III parts, participants will be randomized to receive either four doses of AntiBKV or four doses of placebo (every four weeks). In phase II, 60 participants will be first randomized (1:1) to receive either four doses of 1,000 mg of AntiBKV or placebo. In an additional dose-comparison extension, another 30 participants will be enrolled and randomized (1:1:1) to receive either four doses of 1,000 mg AntiBKV, four doses of 500 mg AntiBKV, or placebo. Based on a Day 141 analysis after phase II the sample size for the phase III part of the trial will be defined. Both the phase II and phase III parts will follow identical study assessments and schedules for participants.
Eligible participants will receive an intravenous infusion of the investigational medicinal product (IMP) that will be administered four times at a four-week interval. For the first ten participants enrolled in the study, the infusion time will be at least 60 minutes. Provided there are no safety concerns observed with the first ten participants the duration of subsequent infusions will be at least 30 minutes.
After administration of the final dose, participants will return as out participants for periodic safety, BKV DNAemia, and PK follow-up assessments until the end of the trial visits, 26 weeks post last IMP application. Regular kidney biopsies will be performed at baseline (prior to infusion) and on Day 141 (8 weeks after full dosing). An additional biopsy will be taken on Day 267 (optional) and if clinically indicated.

Start Date10 Apr 2023

Sponsor / Collaborator

Memo Therapeutics AG

NCT05358106

/ CompletedPhase 1

A Phase 1, Single-blind, Partially Randomized, Placebo-controlled Study to Assess the Safety, Tolerability and Pharmacokinetics of Single and Multiple Ascending Intravenous Doses of AntiBKV in Healthy Adult Volunteers.

BK virus (BKV) is a member of the polyomavirus family with a prevalence of up to 90% in the general population. In immunocompromized individuals, such as kidney transplant recipients (KTRs) who receive immunosuppressant therapy to prevent graft rejection, BKV turns into an opportunistic pathogen. BK viremia has been reported to occur in 10-30% of KTRs. BKV is recognized as a leading cause of impaired graft function and premature transplant loss, and is therefore a serious condition in kidney transplant patients.
At present, there are no effective agents specifically against BKV available and thus no standard treatment that can effectively reduce or prevent BKV infection/reactivation after renal transplantation. Therefore, the proposed indication for the AntiBKV neutralizing antibody is the treatment of BK virus infections and prevention of BK virus associated complications in KTRs.
This study has been designed to evaluate the safety, tolerability, and pharmacokinetic of ascending doses of AntiBKV, a fully human highly neutralising antibody against BKV, administered as a single or multiple intravenous infusions to healthy adult participants. The data obtained in this study will provide the basis for further clinical development of AntiBKV.

Start Date09 May 2022

Sponsor / Collaborator

Memo Therapeutics AG

100 Clinical Results associated with Potravitug

100 Translational Medicine associated with Potravitug

100 Patents (Medical) associated with Potravitug

Literatures (Medical) associated with Potravitug

01 Aug 2025·CTS-Clinical and Translational Science

First‐In‐Human, Randomized, Placebo‐Controlled, SAD and MAD Trial to Evaluate Safety, Tolerability, and PK/PD Modeling of Potravitug in Healthy Adults

Article

Author: Eicher, Barbara ; May, Marcus ; Beck, Juergen ; Bialek‐Waldmann, Julia K. ; Wright, Andrew ; Seidenberg, Jemima ; Gruver, Scott ; Parzmair, Gerald P. ; Grant, Joshuaine

ABSTRACT:

BK polyomavirus (BKPyV) affects 10%–30% of kidney‐transplant recipients receiving immunosuppressive therapy, potentially leading to nephropathy, graft dysfunction, graft loss, and increased mortality. Despite the medical need, no targeted therapies exist. This first‐in‐human trial evaluated the safety, tolerability, pharmacokinetics, and immunogenicity of potravitug, a novel fully human antibody against BKPyV. This partially randomized, single‐blinded, and placebo‐controlled trial enrolled 40 healthy participants randomized (3:1) to receive either single or multiple ascending doses (SAD/MAD) of potravitug or placebo intravenously. In the SAD phase, 16 participants were enrolled in 4 cohorts (n = 4 each) with escalating doses of 100, 500, 1000, and 2000 mg. In the MAD phase, 24 participants were enrolled in 3 consecutive cohorts (n = 8 each) with escalating doses of 500, 1000, and 2000 mg administered four times at four‐week intervals. The primary outcome was incidence, frequency, and severity of treatment‐emergent adverse events (TEAEs). Secondary outcomes included pharmacokinetic parameters and incidence of anti‐drug antibodies. The ex vivo neutralization capacity was an exploratory pharmacodynamic outcome. In SAD cohorts, 17 TEAEs occurred in 7 (58.3%) active and 3 in 2 (50.0%) placebo recipients. In MAD cohorts, 49 TEAEs occurred in 13 (72.2%) active and 21 in 5 (83.3%) placebo recipients. No dose‐limiting toxicities or anti‐drug antibodies were detected, indicating a favorable safety profile. Dose‐proportional increases in Cmax and AUC, with a half‐life characteristic of monoclonal antibodies, were observed. Based on pharmacokinetic‐pharmacodynamic modeling, a 1000 mg intravenous dose administered four times at four‐week intervals is expected to maintain sufficient drug concentrations and receptor occupancy of VP1 (BKPyV major capsid protein) in both the blood and kidney for at least 1 year.

Marine drugs

Targeted Metabolite Fingerprints of Thirteen Gambierdiscus, Five Coolia and Two Fukuyoa Species

Article

Author: Puddick, Jonathan ; Prinsep, Michèle R. ; Passfield, Emillie M. F. ; Finch, Sarah C. ; Nishimura, Tomohiro ; Rhodes, Lesley L. ; Smith, Kirsty F. ; Harwood, D. Tim ; Murray, J. Sam ; Mudge, Elizabeth M. ; Adachi, Masao ; Funaki, Hiroshi ; van Ginkel, Roel

The genus Gambierdiscus produces an array of bioactive hydrophilic and lipophilic secondary metabolites that range in mode of action and toxicity. In this study, the metabolite fingerprint was mapped for thirteen Gambierdiscus, five Coolia and two Fukuyoa species (34 isolates) by assessing the production of 56 characterised secondary metabolites. Gambierdiscus polynesiensis was the only species to produce Pacific-ciguatoxin-3B (P-CTX3B), P-CTX3C, iso-P-CTX3B/C, P-CTX4A, P-CTX4B and iso-P-CTX4A/B. G. australes produced maitotoxin-1 (MTX-1) and MTX-5, G. cheloniae produced MTX-6 and G. honu produced MTX-7. Ubiquitous production of 44-methylgambierone was observed amongst all the Gambierdiscus isolates, with nine species also producing gambierone. Additional gambierone analogues, including anhydrogambierone (tentatively described herein), were also detected in all Gambierdiscus species, two Coolia and two Fukuyoa species. Gambieroxide was detected in G. lewisii and G. pacificus and gambieric acid A was detected in ten Gambierdiscus species, with G. australes (CAWD381) being the only isolate to produce gambieric acids A–D. This study has demonstrated that the isolates tested to date produce the known CTXs or MTXs, but not both, and highlighted several species that produced ‘unknown’ compounds displaying characteristics of cyclic polyethers, which will be the focus of future compound discovery efforts.

Pharmacological reports : PR

In vivo effects of high-dose methotrexate on bone remodeling in rats.

Article

Author: Cegieła, Urszula ; Folwarczna, Joanna ; Sliwiński, Leszek ; Kaczmarczyk-Sedlak, Ilona

Methotrexatae (MTX) is a folate antagonist. MTX osteopathy is well recognized to accompany a high-dose therapy with this drug for the treatment of childhood malignancy. Clinical tests also show that low-dose MTX used in the treatment of rheumatoid arthritis may impair bone formation in a population already predisposed to osteoporosis. However, results of clinical tests are hard to interpret, as it is necessary to take into account malignancy-induced changes in the osseous tissue, long-term immobility and concurrent administration of glucocorticosteroids. We conducted in vivo tests to evaluate the effects of oral and intramuscular administration of high dose of MTX on bone remodeling processes in rats. Effects of MTX on the processes of bone remodeling were evaluated by assessing macrometric and histomorphometric parameters as well as mechanical properties of the femur. The tests were carried out on male Wistar rats. Animals were divided into four groups, composed of 7 animals each: Control group (0.9% NaCl solution), MTX-1 po group (MTX at the dose of 1 mg/kg po daily for 10 days: every day for the first five days, and after an 18-day interval, every day for five days), MTX-1 im group (MTX at the dose of 1 mg/kg im daily for 10 days: every day for the first five days, and after an 18-day interval, every day for five days), MTX-5 im group (MTX at the dose 5 mg/kg im daily for 2 days a week for the period of four weeks). Changes in bone remodeling were examined 4 weeks after the first MTX administration. These results show that MTX administered intramuscularly at high doses inhibited the formation and mineralization of new osseous matrix and impaired mechanical properties of the femoral bone, whereas its oral administration had no effect on bone remodeling in rats.

News (Medical) associated with Potravitug

22 Jul 2026

·www.biospace.com

Ipsen completes acquisition of Memo Therapeutics AG, adding first-in-class asset to Ipsen’s Rare Disease pipeline

PARIS, FRANCE, 22 JULY 2026 - Ipsen (Euronext: IPN; ADR: IPSEY) announced today it has completed the acquisition of Memo Therapeutics AG, a late-stage biotech company focused on potravitug, an anti-BK polyomavirus monoclonal antibody. About potravitug Potravitug is a first-in-class monoclonal antibody targeting BK polyomavirus (BKPyV) reactivation in kidney transplant recipients. It has shown promising results in clinical trials, demonstrating a significant anti-viral response and resolution of BKPyV associated nephropathy. These findings are based on the Phase II SAFE KIDNEY II trial, the largest placebo-controlled study conducted in this patient population, with additional analyses presented at leading international renal and transplant congresses further supporting its clinical pro the next stages of clinical development. About BK polyomavirus BK polyomavirus (BKPyV) is a common virus that most people are exposed to in childhood and usually remains inactive in the body. i However, in people with a weakened immune system, including kidney transplant recipients taking anti-rejection medication, the virus can reactivate and multiply. Around 90% of kidney transplant recipients are positive for BKPyV serotype, ii and high levels of BKPyV in the blood affect approximately 30% of patients within the first year after transplant indicating reactivation of the virus. iii BK polyomavirus reactivation and associated nephropathy (BKVAN) can have serious consequences, including an increased risk of graft loss and the need for dialysis or re-transplantation. There are currently no approved targeted therapies for BKPyV and clinical management is focused on balancing graft protection with BKPyV control through reducing the immunosuppression. iv , v Over 100,000 kidney transplants are performed each year worldwide, and in the U.S. >28,000 are performed each year, with a further >90,000 patients on the waiting list for a transplant. vi About Ipsen We are a global biopharmaceutical company with a focus on bringing transformative medicines to patients in three therapeutic areas: Oncology, Rare Disease and Neuroscience. Our pipeline is fueled by internal and external innovation and supported by nearly 100 years of development experience and global hubs in the U.S., France and the U.K. Our teams in more than 40 countries and our partnerships around the world enable us to bring medicines to patients in more than 100 countries. ezstandalone.cmd.push(function () { ezstandalone.showAds(131); }); Ipsen is listed in Paris (Euronext: IPN) and in the U.S. through a Sponsored Level I American Depositary Receipt program (ADR: IPSEY). For more information, visit ipsen.com . Ipsen Contacts Investors Henry Wheeler henry.wheeler@ipsen.com +33 7 66 47 11 49 Khalid Deojee khalid.deojee@ipsen.com +33 6 66 01 95 26 Media Sally Bain sally.bain@ipsen.com +1 857 320 0517 Anne Liontas anne.liontas.ext@ipsen.com +33 7 67 34 72 96 Disclaimers and/or forward-looking statements The forward-looking statements, objectives and targets contained herein are based on Ipsen’s management strategy, current views and assumptions. Such statements involve known and unknown risks and uncertainties that may cause actual results, performance or events to differ materially from those anticipated herein. All of the above risks could affect Ipsen’s future ability to achieve its financial targets, which were set assuming reasonable macroeconomic conditions based on the information available today. Use of the words ‘believes’, ‘anticipates’ and ‘expects’ and similar expressions are intended to identify forward-looking statements, including Ipsen’s expectations regarding future events, including regulatory filings and determinations. Moreover, the targets described in this document were prepared without taking into account external-growth assumptions and potential future acquisitions, which may alter these parameters. These objectives are based on data and assumptions regarded as reasonable by Ipsen. These targets depend on conditions or facts likely to happen in the future, and not exclusively on historical data. Actual results may depart significantly from these targets given the occurrence of certain risks and uncertainties, notably the fact that a promising medicine in early development phase or clinical trial may end up never being launched on the market or reaching its commercial targets, notably for regulatory or competition reasons. Ipsen must face or might face competition from generic medicine that might translate into a loss of market share. Furthermore, the research and development process involves several stages each of which involves the substantial risk that Ipsen may fail to achieve its objectives and be forced to abandon its efforts with regards to a medicine in which it has invested significant sums. Therefore, Ipsen cannot be certain that favorable results obtained during preclinical trials will be confirmed subsequently during clinical trials, or that the results of clinical trials will be sufficient to demonstrate the safe and effective nature of the medicine concerned. There can be no guarantees a medicine will receive the necessary regulatory approvals or that the medicine will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements. Other risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and healthcare legislation and risks arising from unexpected regulatory or political changes such as changes in tax regulation and regulations on trade and tariffs, such as protectionist measures, especially in the United States; global trends toward healthcare cost containment; technological advances, new medicine and patents attained by competitors; challenges inherent in new-medicine development, including obtaining regulatory approval; Ipsen’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of Ipsen’s patents and other protections for innovative medicines; and the exposure to litigation, including patent litigation, and/or regulatory actions. Ipsen also depends on third parties to develop and market some of its medicines which could potentially generate substantial royalties; these partners could behave in such ways which could cause damage to Ipsen’s activities and financial results. Ipsen cannot be certain that its partners will fulfil their obligations. It might be unable to obtain any benefit from those agreements. A default by any of Ipsen’s partners could generate lower revenues than expected. Such situations could have a negative impact on Ipsen’s business, financial position or performance. Ipsen expressly disclaims any obligation or undertaking to update or revise any forward-looking statements, targets or estimates contained in this press release to reflect any change in events, conditions, assumptions or circumstances on which any such statements are based, unless so required by applicable law. Ipsen’s business is subject to the risk factors outlined in its registration documents filed with the French Autorité des Marchés Financiers. The risks and uncertainties set out are not exhaustive and the reader is advised to refer to Ipsen’s latest Universal Registration Document, available on ipsen.com . i ii B. Demey et al. Risk factors for BK viremia and nephropathy after kidney transplantation: a systematic review. J Clin Virol. 2018 Dec;109:6-12. B. Demey et al. Risk factors for BK viremia and nephropathy after kidney transplantation: a systematic review. J Clin Virol. 2018 Dec;109:6-12. iii S. Kant et al. BK Virus Nephropathy in Kidney Transplantation: A State-of-the-Art Review. Viruses 2022 Jul 25; 14 (8):1616 iv C.N. Kotton et al. The second international consensus guidelines on the management of BK polyomavirus in kidney transplantation. Transplantation. 2024 Sep 1;108(9):1834-1866. v UK Guidelines: UK Guideline on Management of Bk Polyomavirus (BKPyV) Infection and Disease Following Kidney Transplantation - British Transplantation Society UK Guideline on Management of Bk Polyomavirus (BKPyV) Infection and Disease Following Kidney Transplantation - British Transplantation Society vi K.L. Lentine et al. OPTN/SRTS 2021 annual data report: kidney. Am. J. Transplant. 23 (2 Suppl 1) (2023). P. S21-S120 Attachment Ipsen PR_Memo Therapeutics_22072026

10 Jul 2026

·pmlive.com

Ipsen to acquire Memo Therapeutics in deal worth more than €700m

Ipsen is set to acquire Memo Therapeutics in a deal worth more than €700m EUR that is focused on potravitug, a phase 2 clinical-stage antibody against the BK polyomavirus (BKPyV). BK polyomavirus-associated nephropathy (BKPyVAN) is a serious and frequent clinical complication in renal transplanted patients that can lead to graft loss and transplant failure. Potravitug is a monoclonal antibody directed against the BK virus VP1 capsid protein. It acts by blocking viral attachment and cellular entry, thereby preventing infection of host cells and subsequent viral replication. Potravitug was granted fast-track designation from the US FDA in May 2023 and orphan drug designation in the EU in December 2025. Christelle Huguet, Head of R&D at Ipsen, said: “With potravitug, we have the opportunity to add a promising first-in-class asset to our rare disease pipeline and address the significant clinical consequences of BK virus–associated nephropathy in kidney transplant recipients, where current standards of care can compromise transplant success and graft outcomes.” Erik van den Berg, CEO of Memo Therapeutics AG commented, “With its deep expertise in developing and commercialising medicines for rare diseases, Ipsen can ensure that this breakthrough asset reaches its full potential to deliver a life-changing difference for thousands of kidney transplant patients with BKPyV infection.” The phase 2 SAFE Kidney II trial is the largest placebo-controlled clinical trial for the treatment of BKPyVAN in kidney transplanted patients, with 95 patients across 22 sites in the US. The full SAFE KIDNEY II data set presented at ATC 2026 further strengthen the clinical rationale for potravitug ahead of the planned SAFE KIDNEY III trial initiation later this year. “BK polyomavirus associated nephropathy is a significant clinical challenge in kidney transplant recipients,” said Darshana Dadhania, medical director of the Kidney and Pancreas Transplant Program, assistant director of the Immunogenetics and Histocompatibility Lab and an associate professor of medicine at Weill Cornell Medicine. “With no approved targeted treatment, clinicians are forced to reduce immunosuppressive therapy which increases the risk of graft rejection and graft loss. Given the frequency and serious consequences of BK virus reactivation, there remains an urgent need for effective therapy that avoids this trade-off.” Memo’s assets and employees not related to potravitug will be transferred to a newly incorporated company, Memorises Bio, retained by Memo’s shareholders. The transaction is expected to close during Q3 2026.

Fast TrackOrphan DrugImmunotherapyPhase 2

02 Jul 2026

·www.pharmaceutical-technology.com

Ipsen bolsters rare disease pipeline in €700m Memo takeover

Ipsen is acquiring Memo Therapeutics and its anti-BK polyomavirus asset, potravitug to bolster its rare disease pipeline. Credit: Piotr Swat / Shutterstock.com. Ipsen has outlaid €700m ($798.4m) to acquire rare disease specialist Memo Therapeutics – enriching its pipeline with a mid-stage clinical asset. As part of the takeover, the Paris, France-based pharma will pay Memo’s shareholders €200m at transaction close, which is expected in the third quarter of 2026. On top of this initial sum, Ipsen has pledged to allocate “in excess of €700m” to shareholders, provided Memo’s BK polyomavirus -targeting antibody reaches specific development, regulatory and sales-based payments. The jewel in Memo’s crown is its lead asset, potravitug, which the company has engineered to treat BK polyomavirus associated nephropathy (BKPyVAN) – a serious kidney complication caused by the reactivation of a dormant childhood virus in patients with weakened immune systems. It most commonly impacts individuals who have had a kidney transplant, as anti-organ rejection drugs can weaken the immune system and allow the virus to become active. US and European regulators granted Potravitug fast-track and orphan designations in 2023 and 2025 respectively. Memo plans to initiate its pivotal Phase III programme on potravitug, dubbed SAFE KIDNEY III, later this year. The drug acts by binding to the BK virus’ VP1 capsid protein, which is key to the virus’s ability to attach to and enter the cell. By suppressing this capacity, potravitug can prevent host cell infection and viral replication – preventing kidney damage these factors can cause. Ipsen’s acquisition of Memo comes just days after the company announced the $1.75bn takeover of blood cancer drug developer, Kartos Therapeutics. The French pharma company secured the rights to Kartos’ Phase III drug through this buyout. Kartos designed the drug, dubbed navtemadlin, to improve on treatment with JAK inhibitor, Jakafi (ruxolitinib), in myelofibrosis. Potravitug’s first-to-market potential As Memo progresses potravitug in BKPyVAN, the company points to positive data obtained on the drug thus far in clinical trials, with a specific focus on the results of the US-based Phase II SAFE Kidney II study (NCT05769582). During the trial, potravitug allowed significantly more patients to achieve lower or undetectable viral loads over placebo. If the drug were to secure approval in BKPyVAN, it would become the first targeted therapy to reach patients in this indication. According to Darshana Dadhania, medical director of the Kidney and Pancreas Transplant Program at Weill Cornell Medicine, BKPyVAN represents a “significant clinical challenge” within the kidney transplant recipient population. This is because clinicians are currently forced to reduce immunosuppressant regimens in affected patients – putting them at risk of graft rejection and loss. “Given the frequency and serious consequences of BK virus reactivation, there remains an urgent need for effective therapy that avoids this trade-off,” Dadhania said.

100 Deals associated with Potravitug

R&D Status

10 top R&D records.

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Indication	Highest Phase	Country/Location	Organization	Date
BK virus infection	Phase 3	United States	Memo Therapeutics AG	10 Apr 2023

Clinical Result

Indication

Phase

Evaluation

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Study	Phase	Population	Analyzed Enrollment	Group	Results	Evaluation	Publication Date


NCT05769582 (SAFE KIDNEY II, PipelineReview) Manual	Phase 2	BK virus infection	95	Potravitug	pymxgxxxyx(ejprhygmhh) = potravitug dosed at 1,000mg achieved a greater reduction in BKPyV DNAemia compared to placebo, with 61.0% of patients receiving potravitug showing a ≥1-log₁₀ reduction from baseline or achieving levels below the lower limit of quantification (“LLOQ”) at week 20, compared to 40.5% in the placebo group. bsehaonpeo (suwziyjqet ) View more	Positive	25 Jul 2025
				Placebo
NCT05769582 (SAFE KIDNEY II, ASN2025 \| GlobeNewswire \| Company_Website)	Phase 2	Polyomavirus Infections	95	Potravitug	kjmxxesqwa(qwcmynedtc) = qqppouceee lortaizrov (kwzvywofpf )	Positive	25 Jul 2025
				placebo	kjmxxesqwa(qwcmynedtc) = qnklknwobr lortaizrov (kwzvywofpf )

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