Effect of Project Orbis participation by the Swiss regulator on submission gaps, review times, and drug approval decisions between 2020 and 2022: a comparative analysis.

BACKGROUND: Expedited market access for novel and efficacious drugs is warranted for patients. Since 2020, Swissmedic (The Swiss Agency for Therapeutic Products) has been participating in Project Orbis, a collaborative parallel-review programme launched by the US Food and Drug Administration (FDA) in 2019 to expedite patient access to cancer drugs. This programme allows regulatory agencies to remain independent in their decisions. We aimed to evaluate the effect of the first 2 years of Project Orbis from the Swissmedic perspective. METHODS: In this comparative analysis, we compared submission gap (time between submission at the FDA and Swissmedic), review time, approval and consensus decision rate, and the approved indications between Swissmedic and the FDA for marketing authorisation applications (MAAs) in oncology submitted to Swissmedic through Project Orbis (Orbis MAAs) or outside of Project Orbis (non-Orbis MAAs) from Jan 1, 2020, to Dec 31, 2021. Swissmedic review time was evaluated with a decision until June 30, 2022. For the decision comparison analysis, non-Orbis oncology MAAs submitted and evaluated from Jan 1, 2009, to Dec 31, 2018 (referred to as the pre-Orbis era) were also considered. Inferential statistics were done using Wilcoxon rank-sum test and the 95% CI for the median was based on binomial distribution. For each hypothesis testing, the significance level was set to 5%. No correction for multiple testing was performed. FINDINGS: We analysed the submission gap, review time, and regulatory decision for 31 Orbis MAAs and 41 non-Orbis MAAs during the Orbis era. The median submission gap was 33·0 days (95% CI 19·0-57·0) for Orbis MAAs versus 168·0 days (56·0-351·0) for non-Orbis MAAs (p<0·0001). The median review time at Swissmedic was 235·5 days (198·0-264·0) for Orbis MAAs versus 314·0 days (279·0-354·0) for non-Orbis MAAs (p=0·0002). Approval rates at Swissmedic were consistent between Orbis MAAs (20 [77%] of 26) and non-Orbis MAAs (31 [76%] of 41). The rate of consensus decisions between Swissmedic and the FDA was 21 (81%) of 26 for Orbis MAAs and 31 (76%) of 41 for non-Orbis MAAs. Swissmedic approval rates were lower for indication extensions than for new active substances for Orbis MAAs (13 [72%] of 18 vs seven [88%] of eight) and non-Orbis MAAs (17 [71%] of 24 vs 14 [82%] of 17). Divergent decisions between agencies were predominantly observed for indication extensions (11 [73%] of 15 divergent decisions). During the pre-Orbis era, Swissmedic approved 61 (88%) of 69 MAAs for new active substances. INTERPRETATION: Submission gap and review time for oncology applications at Swissmedic were significantly reduced by participation in Project Orbis, and approval consensus decisions were increased between agencies. These findings suggests that participating in Project Orbis could lead to faster patient access to drugs. FUNDING: None.

Decision-making at Swissmedic, the Swiss regulatory agency, with a focus on (neo)adjuvant cancer treatments.

INTRODUCTION: Additional considerations are required for the benefit-risk assessment of new drugs or indications in the setting of (neo)adjuvant cancer treatment as compared to the metastatic/advanced setting, possibly leading to different decision patterns for the (neo)adjuvant versus the metastatic and advanced setting within a health authority but also among different health authorities. METHODS: We analyzed regulatory decisions at the Swiss Agency for Therapeutic Products Swissmedic (SMC) for all oncology indications (mostly metastatic indications) and indications in the (neo)adjuvant setting and compared these to decisions taken by the European Medicines Agency (EMA) and the United States Food and Drug Administration (FDA). RESULTS: Comparing the positive and negative decisions within the Swiss Agency for Therapeutic Products Swissmedic (SMC) between July 2017 and Dec 2021 the approval rates were with 66.7% lower for (neo)adjuvant indications versus 88.4% in the metastatic and advanced indications. While the approval rates for metastatic and advanced New Active Substances (NAS) applications were similar at SMC as compared to the EMA and the FDA, they were lower for (neo)adjuvant applications at SMC as compared to the EMA and the FDA. The underlying reason in all cases with divergent decisions at SMC as compared to EMA and FDA was that no overall survival (OS) benefit as compared to control arm has been observed in the submitted data package. CONCLUSION: Approval and consensus decision rates at SMC in comparison to EMA and FDA were lower for (neo)adjuvant indications but not for advanced and metastastic NAS oncology indications.

[Anorectal melanoma : Update on clinical presentation, diagnosis and treatment]. / Anorektales malignes Melanom : Aktuelles zu Klinik, Diagnostik und Therapie.

Anorectal melanomas are a rare malignant type of cancer and pose a diagnostic challenge due to their hidden anatomical location. They are associated with nonspecific clinical symptoms and are therefore often misinterpreted as benign disease. The result is delayed diagnosis in the locally advanced or metastasized stage and an unfavorable prognosis. Given the overall low incidence of the tumor, no consensus guidelines for diagnosis or therapy are established either internationally or nationally at present. The present work intends to provide a comprehensive overview of the clinical aspects, diagnostics, and therapeutic approaches of anorectal melanoma based on the currently available literature.

Use and perceived utility of [18 F]FDG PET/CT in neuroendocrine neoplasms: A consensus report from the European Neuroendocrine Tumor Society (ENETS) Advisory Board Meeting 2022.

Somatostatin receptor (SST) PET/CT is the gold standard for well-differentiated neuroendocrine tumours (NET) imaging. Higher grades of neuroendocrine neoplasms (NEN) show preferential [18F]FDG (FDG) uptake, and even low-grade NET may de-differentiate over time. FDG PET/CT's prognostic role is widely accepted; however, its impact on clinical decision-making remains controversial and its use varies widely. A questionnaire-based survey on FDG PET/CT use and perceived decision-making utility in NEN was submitted to the ENETS Advisory Board Meeting attendees (November 2022, response rate = 70%). In 3/15 statements, agreement was higher than 75%: (i) FDG was considered useful in NET, irrespective of grade, in case of mis-matched lesions (detectable on diagnostic CT but negative/faintly positive on SST PET/CT), especially if PRRT is contemplated (80%); (ii) in NET G3 if curative surgery is considered (82%); and (iii) in NEC prior to surgery with curative intent (98%). FDG use in NET G3, even in the presence of matched lesions, as a baseline for response assessment was favoured by 74%. Four statements obtained more than 60% consensus: (i) FDG use in NET G3 if locoregional therapy is considered (65%); (ii) in neuroendocrine carcinoma before initiating active therapy as a baseline for response assessment (61%); (iii) biopsy to re-assess tumour grade prior to a change in therapeutic management (68%) upon detection of FDG-positivity on the background of a prior G1-2 NET; (iv) 67% were in favour to reconsider PRRT to treat residual SST-positive lesions after achieving complete remission on FDG of the SST-negative disease component. Multidisciplinary opinion broadly supports the use of FDG PET/CT for characterisation of disease biology and to guide treatment selection across a range of indications, despite the lack of full consensus in many situations. This may reflect existing clinical access due to lack of reimbursement or experience with this investigation, which should be addressed by further research.

Regulatory Review Duration and Differences in Submission Times of Drugs in the United States and Europe, 2011 to 2020.

The speed of drug regulatory agencies in the United States and Europe is often a source of discussion. The objective of this research was to assess regulatory review duration of first and supplementary indications approved between 2011 and 2020 in the United States and Europe (European Union [EU] and Switzerland) and differences in submission times between the United States and Europe. Descriptive statistics were applied to review times between the jurisdictions and across the therapeutic areas. A regression analysis was done to estimate the association between approval agency and review times. The primary analysis cohort included 241 drugs approved in the United States, the EU, and Switzerland. Of these, 128 drugs had supplemental indications (331 in total) in the United States and 87 had supplemental indications (206 in total) in the EU. Overall median review duration from submission to approval subtracting the clock stop period was 39 weeks in the United States, 44 weeks in the EU, and 44 weeks in Switzerland. When review times within each drug were compared, the European Medicines Agency took a median of 3.7 weeks (IQR, -6.7 to 14.9 weeks) longer than the U.S. Food and Drug Administration and Swissmedic a median of 0.3 weeks (IQR, -10.6 to 15.3 weeks) longer. Median total review duration for supplemental indications was 26 weeks in the United States and 40 weeks in the EU. Applications were submitted a median of 1.3 and 17.9 weeks later in the EU and Switzerland, respectively, than in the United States. The regression analysis showed small differences in submission times between the United States and the EU (-2.1 weeks [95% CI, -11.7 to 7.6 weeks]) and larger differences between the United States and Switzerland (33.0 weeks [CI, 23.1 to 42.8 weeks]). It would be beneficial for patients if differences in submission times between the United States and Europe continue to be minimized.

Comparative Expedited Regulatory Programs of U.S Food & Drug Administration and Project Orbis Partners.

Project Orbis was initiated in May 2019 by the Oncology Center of Excellence to facilitate faster patient access to innovative cancer therapies by providing a framework for concurrent submissions and review of oncology products among international partners. Since its inception, Australia's Therapeutic Goods Administration (TGA), Canada's Health Canada (HC), Singapore's Health Sciences Authority (HSA), Switzerland's Swissmedic (SMC), Brazil's National Health Surveillance Agency (ANVISA), United Kingdom's Medicines and Healthcare Products Regulatory Agency (MHRA), and most recently Israel's Ministry of Health (IMoH) Medical Technologies, Health Information, Innovation and Research (MTIIR) Directorate, have joined Project Orbis. While each country has its own expedited review pathways to bring promising therapies to patients, there are some similarities and differences in pathways and timelines. FDA's fast-track designation and MHRA's marketing authorization under exceptional circumstances (MAEC) allow non-clinical and limited clinical evidence to support approval under these programs. HC's Extraordinary Use New Drug (EUND) pathway allows granting exceptional use authorization with limited clinical evidence. ANVISA, HSA, MTIIR, and TGA do not have standard pathways that allow non-clinical evidence and limited clinical evidence. While there is no definite regulatory pathway for HSA, the current framework for approval does allow flexibility in the type of data (non-clinical or clinical) required to demonstrate the benefit-risk profile of a product. HSA may register a product if the agency is satisfied that the overall benefit outweighs the risk. All Project Orbis Partner (POP) countries have similar programs to the FDA accelerated approval program except ANVISA. Although HSA and MTIIR do not have defined pathways for accelerated approval programs, there are opportunities to request accelerated approval per these agencies. All POP countries have pathways like the FDA priority review except MHRA. Priority review timelines for new drugs range from 120 to 264 calendar days (cd). Standard review timelines for new drugs range from 180 to 365 cd.

Re-evaluating the need for chronic toxicity studies with therapeutic monoclonal antibodies, using a weight of evidence approach.

To support registration of monoclonal antibodies (mAbs) for chronic indications, 6-month toxicity studies have historically been conducted. Experience with mAb development has shown a relatively benign and well-understood safety profile for this class, with most toxicity findings anticipated based on pharmacology. We evaluated whether a 6-month toxicity study is necessary to assess the long-term safety of mAbs. Data on First-in-Human (FIH)-enabling and chronic toxicity studies were shared for 142 mAbs submitted by 11 companies. Opportunities to further optimize study designs to reduce animal usage were identified. For 71% of mAbs, no toxicities or no new toxicities were noted in chronic studies compared to FIH-enabling study findings. New toxicities of potential concern for human safety or that changed trial design were identified in 13.5% of cases, with 7% being considered critical and 2% leading to program termination. An iterative, weight-of-evidence model which considers factors that influence the overall risk for a mAb to cause toxicity was developed. This model enables an evidence-based justification, suggesting when 3-month toxicity studies are likely sufficient to support late-stage clinical development and registration for some mAbs.

The use of recovery animals in nonclinical safety assessment studies with monoclonal antibodies: further 3Rs opportunities remain.

Assessment of reversibility from nonclinical toxicity findings in animals with potential adverse clinical impact is required during pharmaceutical development, but there is flexibility around how and when this is performed and if recovery animals are necessary. For monoclonal antibodies (mAbs) and in accordance with ICH S6(R1) if inclusion of recovery animals is warranted, this need only occur in one study. Data on study designs for first-in-human (FIH)-enabling and later-development toxicity studies were shared from a recent collaboration between the NC3Rs, EPAA, Netherlands Medicines Evaluation Board (MEB) and 14 pharmaceutical companies. This enabled a review of practices on recovery animal use during mAb development and identification of opportunities to reduce research animal use. Recovery animals were included in 68% of FIH-enabling and 69% of later-development studies, often in multiple studies in the same program. Recovery groups were commonly in control plus one test article-dosed group or in all dose groups (45% of studies, each design). Based on the shared data review and conclusions, limiting inclusion of recovery to a single nonclinical toxicology study and species, study design optimisation and use of existing knowledge instead of additional recovery groups provide opportunities to further reduce animal use within mAb development programs.

Immunosuppression Profile of CFZ533 (Iscalimab), a Non-Depleting Anti-CD40 Antibody, and the Presence of Opportunistic Infections in a Rhesus Monkey Toxicology Study.

CFZ533 (iscalimab) is a nondepleting anti-CD40 antibody intended for inhibition of transplant organ rejection and treatment of autoimmune diseases. In a safety assessment in rhesus monkeys, CFZ533 was administered for 13 weeks up to 150 mg/kg/week subcutaneously. CFZ533 was shown previously to completely inhibit primary and secondary T-cell-dependent antibody responses. CD40 is expressed on B cells, antigen-presenting cells, and endothelial and epithelial cells, but is not expressed on T cells. Here, we demonstrate the complete suppression of germinal center formation in lymphoid organs. CFZ533 was well tolerated and did not cause any dose-limiting toxicity. However, the histological evaluation revealed increased numbers of CD4+ and CD8+ T cells in the T-cell-rich areas of lymph nodes enlarged in response to observed adenovirus and Cryptosporidium infections which suggest that T-cell immune function was unaffected. Background infections appear as the condition leading to unraveling the differential immunosuppressive effects by CFZ533. The presence of T cells at lymph nodes draining sites of infections corroborates the immunosuppressive mechanism, which is different from calcineurin-inhibiting drugs. Furthermore, CFZ533 did not show any hematological or microscopic evidence of thromboembolic events in rhesus monkeys, which were previously shown to respond with thromboembolism to treatment with anti-CD154 antibodies.

FDA Approval Summary: Osimertinib for Adjuvant Treatment of Surgically Resected Non-Small Cell Lung Cancer, a Collaborative Project Orbis Review.

On December 18, 2020, the FDA approved osimertinib as adjuvant therapy in patients with non-small cell lung cancer (NSCLC) whose tumors have EGFR exon 19 deletions or exon 21 (L858R) mutations, as detected by an FDA-approved test. The approval was based on the ADAURA study, in which 682 patients with NSCLC were randomized to receive osimertinib (n = 339) or placebo (n = 343). Disease-free survival (DFS) in the overall population (stage IB-IIIA) was improved for patients who received osimertinib, with an HR of 0.20; 95% confidence interval (CI), 0.15-0.27; P < 0.0001. Median DFS was not reached for the osimertinib arm compared with 27.5 months (95% CI, 22.0-35.0) for patients receiving placebo. Overall survival data were not mature at the time of the approval. This application was reviewed under FDA's Project Orbis, in collaboration with Australia Therapeutic Goods Administration, Brazil ANVISA, Health Canada, Singapore Health Sciences Authority, Switzerland Swissmedic, and the United Kingdom Medicines and Healthcare products Regulatory Agency. This is the first targeted therapy adjuvant approval for NSCLC and has practice-changing implications.

Nonclinical Development of Biologics: Integrating Safety, Pharmacokinetics, and Pharmacodynamics to Create Smarter and More Flexible Nonclinical Safety Programs Optimizing Animal Use.

Safety assessment of biological drugs has its challenges due to the multiple new different modalities, for example, antibody-drug conjugates, bispecifics, nanobodies, fusion proteins and advanced therapy medicinal products (ATMPs), their different pharmacokinetic and pharmacodynamic properties, and their ability to trigger immunogenicity and toxicity. In the public and in the pharmaceutical industry, there is a strong and general desire to reduce the number of animals used in research and development of drugs and in particular reducing the use of nonhuman primates. Important discussions and activities are ongoing investigating the smarter designs of early research and dose range finding studies, reuse of animals, and replacing animal experiments with in vitro studies. Other important challenges include absence of a relevant species and design of studies and developing genetically modified animals for special investigative toxicology studies. Then, the learnings and challenges from the development of the first ATMPs are available providing valuable insights in the development path for these new potentially transformative treatments. Finally, development of strategies for assessment of immunogenicity and prediction of translation of immunogenicity and associated findings to the clinic. On this, the eighth meeting for the European BioSafe members, these challenges served as the basis for the presentations and discussions during the meeting. This article serves as the workshop report reviewing the presentations and discussions at the meeting.

Nonclinical Studies that Support Viral Vector-Delivered Gene Therapies: An EFPIA Gene Therapy Working Group Perspective.

Nonclinical development strategies for gene therapies are unique from other modalities. The European Federation of Pharmaceutical Industries and Associates (EFPIA) Gene Therapy Working Group surveyed EFPIA member and nonmember pharmaceutical and biotechnology companies about their current practices for designing and implementing nonclinical toxicology studies to support the development of viral vector-delivered in vivo gene therapies. Compiled responses from 17 companies indicated that these studies had some variability in species selection, study-design elements, biodistribution, immunogenicity or genomic insertion assessments, safety pharmacology, and regulatory interactions. Although there was some consistency in general practice, there were examples of extreme case-by-case differences. The responses and variability are discussed herein. Key development challenges were also identified. Results from this survey emphasize the importance for harmonization of regulatory guidelines for the development of gene-therapy products, while still allowing for case-by-case flexibility in nonclinical toxicology studies. However, the appropriate timing for a harmonized guidance, particularly with a platform that continues to rapidly evolve, remains in question.

Project Orbis: Global Collaborative Review Program.

In 2019, the FDA Oncology Center of Excellence launched Project Orbis, a global collaborative review program to facilitate faster patient access to innovative cancer therapies across multiple countries. Project Orbis aims for concurrent submission, review, and regulatory action for high-impact clinically significant marketing applications among the participating partner countries. Current Project Orbis partners (POP) include the regulatory health authorities (RHA) of Australia, Brazil, Canada, Singapore, and Switzerland. Project Orbis leverages the existing scientific and regulatory partnerships between the various RHA under mutual confidentiality agreements. While FDA serves as the primary coordinator for application selection and review, each country remains fully independent on their final regulatory decision. In the first year of Project Orbis (June 2019 to June 2020), a total of 60 oncology marketing applications were received, representing 16 unique projects, and resulting in 38 approvals. New molecular entities, also known as new active substances, comprised 28% of the received marketing applications. The median time gap between FDA and Orbis submission dates was 0.6 months with a range of -0.8 to 9.0 months. Across the program, the median time-to-approval was similar between FDA (4.2 months, range 0.9-6.9, N = 18) and the POP (4.4 months, range 1.7-6.8, N = 20). Participating countries have signified a strong commitment for continuation and growth of the program. Project Orbis expansion considerations include the addition of more countries and management of more complex applications.

Validation of the revised 2018 AAST-OIS classification and the CT severity index for prediction of operative management and survival in patients with blunt spleen and liver injuries.

OBJECTIVES: Non-operative management (NOM) is increasingly utilised in blunt abdominal trauma. The 1994 American Association of Surgery of Trauma grading (1994-AAST) is applied for clinical decision-making in many institutions. Recently, classifications incorporating contrast extravasation such as the CT severity index (CTSI) and 2018 update of the liver and spleen AAST were proposed to predict outcome and guide treatment, but validation is pending. METHODS: CT images of patients admitted 2000-2016 with blunt splenic and hepatic injury were systematically re-evaluated for 1994/2018-AAST and CTSI grading. Diagnostic accuracy, diagnostic odds ratio (DOR), and positive and negative predictive values were calculated for prediction of in-hospital mortality. Correlation with treatment strategy was assessed by Cramer V statistics. RESULTS: Seven hundred and three patients were analysed, 271 with splenic, 352 with hepatic and 80 with hepatosplenic injury. Primary NOM was applied in 83% of patients; mortality was 4.8%. Comparing prediction of mortality in mild and severe splenic injuries, the CTSI (3.1% vs. 10.3%; diagnostic accuracy = 75.4%; DOR = 3.66; p = 0.006) and 1994-AAST (3.3% vs. 10.5%; diagnostic accuracy = 77.9%; DOR = 3.45; p = 0.010) were more accurate compared with the 2018-AAST (3.4% vs. 8%; diagnostic accuracy = 68.2%; DOR = 2.50; p = 0.059). In hepatic injuries, the CTSI was superior to both AAST classifications in terms of diagnostic accuracy (88.7% vs. 77.1% and 77.3%, respectively). CTSI and 2018-AAST correlated better with the need for surgery in severe vs. mild hepatic (Cramer V = 0.464 and 0.498) and splenic injuries (Cramer V = 0.273 and 0.293) compared with 1994-AAST (Cramer V = 0.389 and 0.255; all p < 0.001). CONCLUSIONS: The 2018-AAST and CTSI are superior to the 1994-AAST in correlation with operative treatment in splenic and hepatic trauma. The CTSI outperforms the 2018-AAST in mortality prediction. KEY POINTS: • Non-operative management of blunt abdominal trauma is increasingly applied and correct patient stratification is crucial. • CT-based scoring systems are used to assess injury severity and guide clinical decision-making, whereby the 1994 version of the American Association of Surgery of Trauma Organ Injury Scale (AAST-OIS) is currently most commonly utilised. • Including contrast media extravasation in CT-based grading improves management and outcome prediction. While the 2018-AAST classification and the CT-severity-index (CTSI) better correlate with need for surgery compared to the 1994-AAST, the CTSI is superior in outcome-prediction to the 2018-AAST.

Interstitial high-dose-rate brachytherapy in the primary treatment of inoperable glioblastoma multiforme.

PURPOSE: To report our results of image-guided interstitial (IRT) high-dose-rate (HDR) brachytherapy (BRT) in the primary treatment of patients with inoperable glioblastoma multiforme (GBM) in the pre-temozolomide period. MATERIAL AND METHODS: Between 1994 and 2004, 17 patients were treated with HDR BRT for inoperable GBM. Of those, only 11 patients were treated with IRT BRT, and the remaining six patients received combined IRT BRT and external beam radiotherapy (EBRT). Patient's median age was 59.3 years (range, 29-83 years) and median tumor volume was 39.3 cm3 (range, 2-162 cm3). The prescribed HDR dose was median 40 Gy (range, 30-40 Gy), delivered twice daily in 5.0 Gy fractions over four consecutive days. Survival from BRT, toxicity as well as the impact of several prognostic factors was evaluated. RESULTS: At a median follow-up of 9.3 months, the median overall survival for the whole population, after BRT alone, and combined BRT with EBRT was 9.3, 7.3, and 10.1 months, respectively. Of the prognostic variables evaluated in univariate analysis, i.e., age, Karnofsky performance score, BRT dose, and tumor volume, only the latter one reached statistical significance. Two patients (11.7%) developed treatment-associated adverse events, with one (5.8%) symptomatic radionecrosis and one (5.8%) severe convulsion episode, respectively. CONCLUSIONS: For patients with inoperable GBM, IRT HDR BRT alone or in combination with EBRT is a safe and effective irradiation method providing palliation without excessive toxicity.

Nonclinical Safety Assessment of CFZ533, a Fc-Silent Anti-CD40 Antibody, in Cynomolgus Monkeys.

CFZ533 is a pathway blocking, nondepleting anti-CD40 antibody that is in clinical development for inhibition of transplant organ rejection and therapy for autoimmune diseases. A 26-week GLP toxicity study in sexually mature Cynomolgus monkeys was conducted in order to support chronic application of CFZ533. CFZ533 was subcutaneously administered at doses up to 150 mg/kg/week and was safe and generally well tolerated. CFZ533 showed no adverse effects for cardiovascular, respiratory, and neurobehavioral endpoints, and no changes were observed for blood lymphocyte and platelet counts or blood coagulation markers. In line with the nondepleting nature of CFZ533, CD20+ B cells in the blood were only marginally reduced. A complete suppression of germinal center (GC) development in lymph nodes and spleen was the most prominent result of post-mortem histological investigations. This was corroborated by an abrogated T-dependent antibody response (TDAR) to the antigen Keyhole Limpet Hemocyanin (KLH) as well as an absence of anti-drug antibodies (ADAs) in the absence of B cell depletion as seen with immunophenotyping and histology. When serum levels of CFZ533 in recovery animals dropped levels necessary for full CD40 occupancy on B cells, all animals were able to mount a TDAR to KLH. All histological changes also reverted to normal appearance after recovery. In summary, CFZ533 was shown to be well tolerated and safe in the 26-week toxicity study with a distinct pharmacodynamic profile in histology and immune function.

Characterization of the in vitro and in vivo properties of CFZ533, a blocking and non-depleting anti-CD40 monoclonal antibody.

The CD40-CD154 costimulatory pathway is essential for T cell-dependent immune responses, development of humoral memory, and antigen presenting cell function. These immune functions have been implicated in the pathology of multiple autoimmune diseases as well as allograft rejection. We have generated CFZ533, a fully human, pathway blocking anti-CD40 monoclonal antibody that has been modified with a N297A mutation to render it unable to mediate Fcγ-dependent effector functions. CFZ533 inhibited CD154-induced activation of human leukocytes in vitro, but failed to induce human leukocyte activation. Additionally, CFZ533 was unable to mediate depletion of human CD40 expressing B cells. In vivo, CFZ533 blocked primary and recall T cell-dependent antibody responses in nonhuman primates and abrogated germinal formation without depleting peripheral blood B cells. We also established a relationship between plasma concentrations of CFZ533 and CD40 pathway-relevant pharmacodynamic effects in tissue. Collectively these data support the scientific rationale and posology for clinical utility of this antibody in select autoimmune diseases and solid organ transplantation.