Approved Monoclonal Antibodies Research Articles

Missense variants in the TNFA epitopes and their effects on interaction with therapeutic antibodies—in silico analysis

BackgroundTumor necrosis factor alpha (TNFA) is an important cytokine that influences multiple biological processes. It is one of the key mediators of acute and chronic systemic inflammatory reactions and plays a central role in several autoimmune diseases. A number of approved monoclonal antibodies (mAbs) are widely used to subside these autoimmune diseases. However, there is a high rate of non-responsiveness to treatments with these mAbs. Therefore, it is important to be able to predict responses of the patients in an individualistic manner to these therapeutic antibodies before administration. In the present study, we used in silico tools to explore the effects of missense variants in the respective epitopes of four therapeutic anti-TNFA mAbs—adalimumab (ADA), certolizumab pegol (CZP), golimumab (GLM), and infliximab (IFX)—on their interactions with TNFA. ResultsThe binding affinities of CZP and ADA to corresponding epitopes appear to be reduced by four (TNFAR131Q, TNFAE135G, TNFAR138Q, and TNFAR138W) and two (TNFAG66C and TNFAG66S) variants, respectively. The binding of GLM and IFX appears to be affected by TNFAR141S and TNFAR138W, respectively. TNFAG66C and TNFAG66S may be associated with autoimmune diseases, whereas TNFAE135G, TNFAR138W, and TNFAR141S may be pathogenic per se. ConclusionThese variants may contribute to the observed inter-individual variability in response to anti-TNFA mAbs treatments and be used as markers to predict responses, and thus optimize therapeutic benefits to the patients.

Isolation and characterization of human anti-CD20 single-chain variable fragment (scFv) from a Naive human scFv library.

CD20 is a receptor expressed on B cells with anonymous functions. The receptor is the target of some food and drug administration (FDA) approved monoclonal antibodies (mAb), such as Rituximab and Obinutuzumab. Blocking CD20 using the aforementioned mAbs has improved Non-Hodgkin Lymphoma (NHL) therapy. All commercial mAbs on the market were raised in non-human animal models. Antibody humanization is inevitable to mitigate immune response. In order to keep the affinity of antibody intact, humanizations are only applied to frameworks which do not eliminate immune response to foreign CDRs sequences. To address this issue, human monoclonal antibody deemed imperative. Herein, we report the isolation and characterization of a fully human single-chain variable fragment (scFv) against the large loop of CD20 from naïve human antibody library. After three rounds of phage display, a library of enriched anti-CD20 scFv was obtained. The polyclonal phage ELISA demonstrated that after each round of phage display, the population of anti-CD20 scFv became dominant. The scFv, G7, with the most robust interaction with CD20 was selected for further characterization. The specificity of G7 scFv was evaluated by ELISA, western blot, and flow cytometry. Detecting CD20 in western blot showed that G7 binds to a linear epitope on CD20 large loop. Next, G7 scFv was also bound to Raji cell (CD20+) while no interaction was recorded with K562 cell line (CD20—). This data attested that the epitope recognized by G7 scFv is accessible on the cell membrane. The affinity of G7 scFv was estimated to be 63.41 ± 3.9 nM. Next, the sensitivity was evaluated to be 2 ng/ml. Finally, G7 scFv tertiary structure was modeled using Graylab software. The 3D structure illustrated two domains of variable heavy (VH) and variable light (VL) connected through a linker. Afterward, G7 scFv and CD20 were applied to in-silico docking using ClusPro to illustrate the interaction of G7 with the large loop of CD20. As the selected scFv from the human antibody library is devoid of interspecies immunogenic amino acids sequences, no humanization or any other modifications are required prior to clinical applications.

528. Hospital Course of Patients Receiving Bamalanivimab: A Real World Analysis

BackgroundMonoclonal antibodies for the outpatient treatment of the novel Coronavirus Disease 2019 (COVID-19) first received emergency use authorization from the Food and Drug Administration in November 2020. These antibodies have been associated with a reduction in emergency department visits and hospitalization through randomized controlled trials. However, modest data is available to describe the outcomes of patients who were hospitalized despite treatment. This study describes real-world outcomes concerning the treatment of COVID-19 with the first approved monoclonal antibody for COVID-19, bamlanivimab, as well as hospital courses associated with patients admitting after receiving the therapy.MethodsThis single-center, retrospective study evaluated real-world data of patients treated with bamlanivimab. The primary endpoint was a composite of emergency department (ED) visits or hospitalization due to worsening COVID-19. Data was analyzed from November 23, 2020 to March 5, 2021. Descriptive statistics were used to analyze the primary endpoint. Secondary endpoints include reported symptoms 24-hours post-infusion and time to symptom resolution in days. Additionally, clinical course of patients hospitalized were analyzed and include average oxygen requirements, median length of stay, and mortality. A subgroup analysis was conducted between patients less than sixty-five years of age and those sixty-five and older.Results619 patients received bamlanivimab during the specified timeframe. The primary endpoint occurred in 34 patients; 11 ED visits and 23 hospitalizations. Baseline characteristics of the patients hospitalized include median age 69 years (IQR 55, 74), 56.5% male, and 82.6% Caucasian. The most common risk factors for severe disease among those hospitalized were age ≥ 65 years and history of diabetes. The clinical course of hospitalized patients varied but 52.9% required nasal cannula for respiratory support and the average length of stay was 4.5 + 4.5 days. Other COVID-19 therapies included dexamethasone in 76.5% of patients and remdesivir in 47.1% of patients. There were no major differences in the subgroup analysis.ConclusionBamlanivimab appears to attenuate the clinical course of COVID-19 in patients who are hospitalized despite treatment.Disclosures All Authors: No reported disclosures

Anti-drug antibodies to antibody-based therapeutics in multiple sclerosis.

Multiple sclerosis is the major demyelinating autoimmune disease of the central nervous system. Relapsing MS can be treated by a number of approved monoclonal antibodies that currently target: CD20, CD25 (withdrawn), CD49d and CD52. These all target potentially pathogenic memory B cell subsets and perhaps functionally inhibit pathogenic T cell function. These consist of chimeric, humanized and fully human antibodies. However, despite humanization it is evident that all of these monoclonal antibodies can induce binding and neutralizing antibodies ranging from < 1% to over 80% within a year of treatment. Importantly, it is evident that monitoring these allow prediction of future treatment-failure in some individuals and treatment cessation and switching therefore potentially limiting disease breakthrough and disability accumulation. In response to the COVID-19 pandemic and the need to avoid hospitals, shortened infusion times and extended dose intervals have been implemented, importantly, subcutaneous delivery of alternative treatments or formulations have been developed to allow for home treatment. Therefore, hospital-based and remote monitoring of ADA could therefore be advantageous to optimize patient responses in the future.

In Vivo Electroporation of Plasmid DNA: A Promising Strategy for Rapid, Inexpensive, and Flexible Delivery of Anti-Viral Monoclonal Antibodies.

Since the first approval of monoclonal antibodies by the United States Food and Drug Administration (FDA) in 1986, therapeutic antibodies have become one of the predominant classes of drugs in oncology and immunology. Despite their natural function in contributing to antiviral immunity, antibodies as drugs have only more recently been thought of as tools for combating infectious diseases. Passive immunization, or the delivery of the products of an immune response, offers near-immediate protection, unlike the active immune processes triggered by traditional vaccines, which rely on the time it takes for the host’s immune system to develop an effective defense. This rapid onset of protection is particularly well suited to containing outbreaks of emerging viral diseases. Despite these positive attributes, the high cost associated with antibody manufacture and the need for a cold chain for storage and transport limit their deployment on a global scale, especially in areas with limited resources. The in vivo transfer of nucleic acid-based technologies encoding optimized therapeutic antibodies transform the body into a bioreactor for rapid and sustained production of biologics and hold great promise for circumventing the obstacles faced by the traditional delivery of antibodies. In this review, we provide an overview of the different antibody delivery strategies that are currently being developed, with particular emphasis on in vivo transfection of naked plasmid DNA facilitated by electroporation.

Quantification of PD-1/PD-L1 Interaction between Membranes from PBMCs and Melanoma Samples Using Cell Membrane Microarray and Time-Resolved Förster Resonance Energy Transfer

Melanoma is a carcinoma known to evade the host immune defenses via the downregulation of the immune response. One of the molecules involved in this mechanism is programmed cell death ligand 1 (PD-L1), which interacts with its receptor, programmed cell death protein 1 (PD-1), expressed on T cells, leading to a reduction in cytokine release and cytotoxic activity, as well as a halt in T-cell proliferation. The approved therapeutic monoclonal antibodies, such as pembrolizumab, target the PD-1/PD-L1 interaction and are revolutionizing cancer treatments. We developed an assay that provides a quantitative readout of PD-1/PD-L1 interactive states between cell membranes of human immune cells (peripheral blood mononuclear cells, PBMCs) and PD-L1-expressing samples. For this purpose, cell membrane microarrays (CMMAs) were developed from membranes isolated from a HT144 cell line and melanoma samples, and PD-L1 expression was quantified using immunofluorescence (IF). CMMAs were incubated with cell membranes of PBMCs expressing PD-1, and the interaction with PD-L1 was quantified by time-resolved Förster resonance energy transfer, in the presence and absence of pembrolizumab as a blocking drug. The developed assay was able to quantify the PD-1/PD-L1 interaction, and this engagement was disrupted in the presence of the blocking antibody. This demonstrates the potential of the method to analyze monoclonal antibody drugs, as well as the functional states of immune checkpoint regulators. Furthermore, our findings provide evidence to support the future implementation of this methodology for both drug discovery and immune system monitoring in cancer, transplantation, and inflammatory and autoimmune diseases.

ISATUXIMAB PLUS CARFILZOMIB AND DEXAMETHASONE IN PATIENTS WITH RELAPSED MULTIPLE MYELOMA AND SOFT-TISSUE PLASMACYTOMAS: IKEMA SUBGROUP ANALYSIS

Isatuximab (Isa) is an approved IgG1 monoclonal antibody that targets a specific epitope of CD38 and kills multiple myeloma (MM) cells via multiple mechanisms. The Phase 3 IKEMA study (NCT03275285) demonstrated that Isa plus carfilzomib (K) and dexamethasone (d) significantly improved progression-free survival (PFS) compared with Kd in patients (pts) with relapsed MM (hazard ratio [HR], 0.531; 99% CI, 0.32–0.89; p = 0.0007), leading to the approval of Isa-Kd in the US for adults with MM with 1–3 prior lines and in the EU for those with ≥1 prior therapy. The presence of soft-tissue plasmacytomas is associated with poor prognosis, and newer therapies are urgently needed. In this post hoc analysis, we evaluated the efficacy and safety of Isa-Kd vs Kd in pts with relapsed MM and pre-existing soft-tissue plasmacytomas. Pts (n = 302) were randomized (3:2) to Isa-Kd (n = 179) or Kd (n = 123). Isa (10 mg/kg IV) was given weekly for 4 weeks, then every 2 weeks. K (20 mg/m 2 days 1–2, then 56 mg/m 2 ) was given twice-weekly 3 of 4 weeks, and d (20 mg) twice-weekly. The independent review committee assessed response based on central radiology review and central lab M-protein using the International Myeloma Working Group criteria. At study entry, 19 (6.3%) pts had soft-tissue plasmacytomas: 12/179 (6.7%) had Isa-Kd and 7/123 (5.7%) had Kd. Overall median (range) duration of exposure in these pts was 41.9 (2–87) weeks for Isa-Kd vs 29.9 (4–83) for Kd, with 41.7% pts still on treatment at cycle 20 in Isa-Kd vs 14.3% pts in Kd. Baseline characteristics in the plasmacytomas subgroup were similar to those in the overall IKEMA intent-to-treat (ITT) population with the exception of ISS stages II (42.1% vs 31.1%) and III (31.6% vs 15.2%), and renal function impairment (38.9% vs 22.1%) which were more prevalent in the plasmacytomas subgroup vs ITT. PFS was improved with Isa-Kd vs Kd: HR, 0.574; 95% CI, 0.125–2.640. Median PFS was 18.76 (95% CI, 4.435–not calculable [NC]) months with Isa-Kd vs NC (0.986–NC) months with Kd. Overall response rate (50.0% vs 28.6%), very good partial response or better (33.3% vs 14.3%), and complete response (25.0% vs 0%, all with minimal residual disease negativity) rates were also improved with Isa-Kd vs Kd. Grade ≥3 TEAE occurred in 12 (100%) pts with Isa-Kd vs 4 (57.1%) with Kd. Grade 5 TEAEs during study treatment occurred in 2 (16.7%) vs 1 (14.3%) pt; serious TEAEs in 9 (75.0%) vs 4 (57.1%); TEAEs leading to discontinuations were 0 (0%) vs 1 (14.3%). Grade 5 events were pneumonia (1 [8.3%], Isa-Kd) and progressive disease (1 [8.3%], Isa-Kd; 1 [14.3%], Kd). In pts with relapsed MM and soft-tissue plasmacytomas, Isa-Kd improved PFS and depth of response compared with Kd alone, with a manageable safety profile, consistent with the benefit observed in the IKEMA study overall population. Isa-Kd is a new treatment option for pts with relapsed MM and soft-tissue plasmacytomas. Sanofi.

P-196: Isatuximab plus Carfilzomib and Dexamethasone in patients with relapsed Multiple Myeloma and soft-tissue Plasmacytomas: IKEMA subgroup analysis

<h3>Background</h3> Isatuximab (Isa) is an approved IgG1 monoclonal antibody that targets a specific epitope of CD38 and kills multiple myeloma (MM) cells via multiple mechanisms. The Phase 3 IKEMA study (NCT03275285) demonstrated that Isa plus carfilzomib (K) and dexamethasone (d) significantly improved progression-free survival (PFS) compared with Kd in patients (pts) with relapsed MM (hazard ratio [HR], 0.531; 99% CI, 0.32–0.89; P=0.0007), leading to the approval of Isa-Kd in the US for adults with MM with 1–3 prior lines and in the EU for those with ≥1 prior therapy. The presence of soft-tissue plasmacytomas is associated with poor prognosis, and newer therapies are urgently needed. In this post hoc analysis, we evaluated the efficacy and safety of Isa-Kd vs Kd in pts with relapsed MM and pre-existing soft-tissue plasmacytomas. <h3>Methods</h3> Pts (N=302) were randomized (3:2) to Isa-Kd (n=179) or Kd (n=123). Isa (10 mg/kg IV) was given weekly for 4 weeks, then every 2 weeks. K (20 mg/m² days 1–2, then 56 mg/m²) was given twice-weekly 3 of 4 weeks, and d (20 mg) twice-weekly. The independent review committee assessed response based on central radiology review and central lab M-protein using the International Myeloma Working Group criteria. <h3>Results</h3> At study entry, 19 (6.3%) pts had soft-tissue plasmacytomas:12/179 (6.7%) had Isa-Kd and 7/123 (5.7%) had Kd. Overall median (range) duration of exposure in these pts was 41.9 (2–87) weeks for Isa-Kd vs 29.9 (4–83) for Kd, with 41.7% pts still on treatment at cycle 20 in Isa-Kd vs 14.3% pts in Kd. Baseline characteristics in the plasmacytomas subgroup were similar to those in the overall IKEMA intent-to-treat (ITT) population with the exception of ISS stages II (42.1% vs 31.1%) and III (31.6% vs 15.2%), and renal function impairment (38.9% vs 22.1%) which were more prevalent in the plasmacytomas subgroup vs ITT. PFS was improved with Isa-Kd vs Kd: HR, 0.574; 95% CI, 0.125–2.640. Median PFS was 18.76 (95% CI, 4.435–not calculable [NC]) months with Isa-Kd vs NC (0.986–NC) months with Kd. Overall response rate (50.0% vs 28.6%), very good partial response or better (33.3% vs 14.3%), and complete response (25.0% vs 0%, all with minimal residual disease negativity) rates were also improved with Isa-Kd vs Kd. Grade ≥3 TEAE occurred in 12 (100%) pts with Isa-Kd vs 4 (57.1%) with Kd. Grade 5 TEAEs during study treatment occurred in 2 (16.7%) vs 1 (14.3%) pt; serious TEAEs in 9 (75.0%) vs 4 (57.1%); TEAEs leading to discontinuations were 0 (0%) vs 1 (14.3%). Grade 5 events were pneumonia (1 [8.3%], Isa-Kd) and progressive disease (1 [8.3%], Isa-Kd; 1 [14.3%], Kd). <h3>Conclusions</h3> In pts with relapsed MM and soft-tissue plasmacytomas, Isa-Kd improved PFS and depth of response compared with Kd alone, with a manageable safety profile, consistent with the benefit observed in the IKEMA study overall population. Isa-Kd is a new treatment option for pts with relapsed MM and soft-tissue plasmacytomas. <h3>Funding</h3> Sanofi.

A novel humanized MUC1 antibody-drug conjugate for the treatment of trastuzumab-resistant breast cancer.

Mucin 1 (MUC1) has been regarded as an ideal target for cancer treatment, since it is overexpressed in a variety of different cancers including the majority of breast cancer. However, there are still no approved monoclonal antibody drugs targeting MUC1. In this study, we generated a humanized MUC1 (HzMUC1) antibody from our previously developed MUC1 mouse monoclonal antibody that only recognizes MUC1 on the surface of tumor cells. Furthermore, an antibody-drug conjugate (ADC) was generated by conjugating HzMUC1 with monomethyl auristatin (MMAE), and the efficacy of HzMUC1-MMAE on the MUC1-positive HER2+ breast cancer in vitro and in 'Xenograft' model was tested. Results from western blot analysis and immunoprecipitation revealed that the HzMUC1 antibody did not recognize cell-free MUC1-N in sera from breast cancer patients. Confocal microscopy analysis showed that HzMUC1 antibody bound to MUC1 on the surface of breast cancer cells. Results from mapping experiments suggested that HzMUC1 may recognize an epitope present in the interaction region between MUC1-N and MUC1-C. Results from colony formation assay and flow cytometry demonstrated that HzMUC1-MMAE significantly inhibited cell growth by inducing G2/M cell cycle arrest and apoptosis in trastuzumab-resistant HER2-positive breast cancer cells. Meanwhile, HzMUC1-MMAE significantly reduced the growth of HCC1954 xenograft tumors by inhibiting cell proliferation and enhancing cell death. In conclusion, our results indicate that HzMUC1-ADC is a novel therapeutic drug that can overcome trastuzumab resistance of breast cancer. HzMUC1-ADC should also be an effective therapeutic drug for the treatment of different MUC1-positive cancers in clinic.

MM-130: Updates from ICARIA-MM, a Phase 3 Study of Isatuximab (Isa) Plus Pomalidomide and Low-Dose Dexamethasone (Pd) vs Pd in Relapsed and Refractory Multiple Myeloma (RRMM)

Background Isa is an approved monoclonal antibody that binds to a specific epitope on the CD38 receptor. Phase 3 ICARIA-MM study (NCT02990338) demonstrated improved progression-free survival (PFS) with Isa-Pd vs Pd (P=0.001) and manageable safety profile. Here, we report updated ICARIA results. Methods Patients with RRMM (N=307) who received ≥2 prior therapies, including lenalidomide (Len) and a proteasome inhibitor (PI), were randomized to Isa-Pd (n=154) or Pd (n=153). Isa was administered intravenously at 10 mg/kg weekly for 4 weeks and every other week thereafter. This pre-planned second interim analysis assessed time to next treatment (TTNT), overall survival (OS), time from randomization to disease progression on first subsequent therapy or death (PFS2), and safety. Results Patients had median 3 prior lines of therapy. As of Oct 1, 2020 (median follow-up, 35.3 months), 27 Isa-Pd patients (18%) vs 12 Pd patients (8%) were still on treatment; 60% vs 72% proceeded to subsequent therapy. Median TTNT: 15.5 months Isa-Pd vs 8.9 months Pd (HR 0.56; 95% CI 0.42–0.74; P Conclusions Isa-Pd demonstrates significant improvement in TTNT and PFS2 vs Pd. A strong trend in OS benefit was seen in the Isa-Pd arm, with approximately 7 months improvement in median OS. The OS profile remains unchanged from prior analyses.

Cytokines: Signalling Improved Immunotherapy?

Immune checkpoint immunotherapies (ICI) are now approved for over 20 types of cancer and there are almost 6000 ongoing clinical trials investigating immuno-modulators as cancer therapies. This review investigated the effect of monoclonal antibody-based immune checkpoint immunotherapies when combined with cytokine therapy. We reviewed published clinical trial results from 2005 to 2020 for studies that used approved monoclonal antibody ICI in combination with the cytokines. Studies that met the search criteria were assessed for treatment efficacy and immunological changes associated with treatment. ICI often fails to result in improved clinical outcomes for patients and lasting protection from cancer recurrence. The use of pro-inflammatory cytokines alongside ICI has been shown to enhance the efficacy of these therapies in vitro and in animal studies. However, the results in human clinical trials are less clear and many clinical trials do not publish results at the end of the trial. A deeper understanding of the molecular interactions between cytokines, tumors, and immune cells is needed to improve overall ICI outcomes and design combination trials. Critical examination of the design and characteristics of previous clinical trials can provide insight into the lack of effective clinical translation for many immunotherapeutic drugs.

Abstract 1274: CCX559 is a potent orally-administered small molecule PD-L1 inhibitor that induces anti-tumor immunity

Abstract Introduction: Cancer cells can escape tumor-specific T cell responses via engagement of inhibitory immune checkpoints. PD-L1/PD-1 interaction is one of the major checkpoints that limit effector T cell function against cancer cells, and monoclonal antibodies that block this interaction have been approved as therapies in multiple tumor indications. As a next generation therapy, small molecule inhibitors of PD-L1 potentially have advantageous properties compared to approved monoclonal antibodies, such as better penetration into solid tumors, reduced immunogenicity, lack of Fc-mediated side effects, convenience of oral administration, and lower cost of goods. We therefore embarked on an effort to identify and develop an orally available small molecule capable of targeting PD-L1/PD-1 interactions. Methods: Inhibition of the PD-L1/PD-1 interaction was measured using a binding assay, followed by a cell culture system assessing PD-1 inhibition of T cell receptor (TCR) activation. Human T cell responses were assessed in vitro using the mixed lymphocyte reaction (MLR) assay, and a human peripheral blood mononuclear cell (PBMC)-mediated tumor cell killing assay. For in vivo studies CCX559 was dosed orally in a syngeneic tumor model and in a human tumor cell/PBMC co-implantation model in immune deficient mice. Results: Using structural information and focused medicinal chemistry, we identified CCX559 as a potent inhibitor of PD-L1 interaction with PD-1. CCX559 prevented PD-L1/PD-1 inhibition of TCR signaling in a cell-based reporter assay, increased IFNγ secretion in allogeneic MLR assays, and increased tumor cell killing by human PBMCs. We demonstrated that CCX559 potentially employs multiple mechanisms to inhibit PD-L1, which are distinct from those published for human anti-PD-L1 antibodies. In murine tumor models, orally administered CCX559 reduced tumor growth similarly to a clinically-approved anti-human PD-L1 antibody. Summary: CCX559 is a highly potent, small molecule PD-L1 inhibitor that can be orally administered. CCX559 enhanced primary human T cell activity in vitro and demonstrated anti-tumor efficacy in two murine tumor models. Based on its unique mechanism of PD-L1 inhibition, strong anti-tumor activity, desirable drug properties, and good safety profile, we plan to advance CCX559 into clinical development in the first half of 2021. Citation Format: Chris Li, Marta Vilalta, Linda S. Ertl, Yu Wang, Yibin Zeng, Pingchen Fan, Christopher Lange, Darren McMurtrie, Ju Yang, Rebecca Lui, Ryan Scamp, Vicky Chhina, Alice Kumamoto, Ryan Ong, Ton Dang, Ashton Easterday, Niky Zhao, Shirley Liu, Rajinder Singh, Israel Charo, Kathleen Sullivan, Thomas J. Schall, Penglie Zhang. CCX559 is a potent orally-administered small molecule PD-L1 inhibitor that induces anti-tumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1274.

Emerging Immune Targets for Treatment of Multiple Myeloma

Introduction:Multiple myeloma (MM) is the 14th leading cause of cancer deaths in the USA. According to NIH cancer statistics, there will be estimated 30,280 new cases and 12,590 deaths due to MM in 2017. Immunotherapy appears to be an appealing treatment modality for MM. Various immunotherapeutic approaches are being used and our aim is to summarize current knowledge on efficacy of non-FDA approved monoclonal antibodies (mAbs), chimeric antigen receptor modified (CAR-T) cells and their targets.Methods:For CAR-T cells literature search was performed on 7/16/2017 in following databases: PubMed, Cochrane, EMBASE, Web of Science and Clinicaltrilas.gov. Only English language studies were included and no publication date limit was applied. For mAbs, phase I/II trials that were complete or recruiting participants were retrieved from clinicaltrials.gov on 7/19/2017. Trials on elotuzumab and daratumumab that have already proven efficacy were not included.Results:Literature search identified a total of 287 articles on CAR-T cells. After detailed scrutiny, 6 studies were included. Citation analysis retrieved one additional study. 7 studies included 86 relapsed and refractory MM (RRMM) patients. Targeted antigens included B-cell maturation antigen (BCMA) (n=4 studies), CD138 (n=1), CD19(n=1) and kappa light chain (n=1). There was significant variation in CAR T cell dose ranging from 1 x 10⁷ to 5 x 10⁸ per patient. Most patients were heavily pretreated with ≥ 6 median prior lines of therapy. Only one study additionally incorporated ASCT. No objective response (OR) was achieved with CD138 and kappa light chain directed CAR T cell therapy. For BCMA and CD19 directed CAR T cell therapy, there was significant variation in efficacy outcomes reported with PR ranging from 2 weeks to 3.2 months (m), VGPR 2m to 5m and sCR 2m to 7+m. Highest incidence of cytokine release syndrome (CRS) of all grades was reported with BCMA directed CAR T cell therapy, ranging from 58-83%. One case of posterior reversible encephalopathy syndrome was reported with BCMA targeted CAR T cell therapy.mAb targets included ICAM-I (BI-505), IL-6 (siltuximab), VEGF (bevacizumab), GRP78 (PAT-SMX), CD40 (dacetuzumab, lucatumumab), CD138 (indatuximab), PD-1 (pembrolizumab, nivolumab, pidilizumab), CD20 (rituximab), CD38 (isatuximab), CD56 (lorvotuzumab), IGF-1R (AVE1642, figitumumab), VEGF (bevacizumab), BAFF (atacicept, tabalumumab) and CD74 (milatuzumab). No objective response (≥PR) was observed with monotherapy with BI-505, siltuximab, bevacizumab, PAT-SMX, AVE-1642, figitumumab, atacicept, milatuzumab, dacetuzumab and nivolumab. Isatuximab (anti-CD38) was the only mAb with promising results (OR 24%) as monotherapy in patients with 6 prior lines of therapy. Most trials employed RRMM patients. Siltuximab in combination with VMP (velcade, melphalan and prednisone) was evaluated in frontline setting without significant improvement reported (CR of 22% vs 27% with VMP alone and PFS of 17 months in both arms). Antibodies tested as conjugates include indatuximab, ravtansine (anti CD138) and lorvotuzumab mertansine (anti CD56). Their results were encouraging when used in combination with Rd (lenalidomide and dexamethasone), OR of 78% with indatuximab +Rd and 56.4% with lorvotuzumab +Rd. MAbs that've been tested in combination therapy include siltuximab (S+Vd, OR 66%), dacetuzumab (D+Rd, OR 39%), indatuximab (I+Rd, OR 78%), isatuximab (I+Rd, OR 64.5%), lorvotuzumab (L+Rd, OR 56.4%) and pembrolizumab (P+Pd, OR 50%).Conclusion:Immunotherapy with mAb and CAR-T therapy seems to offer very promising results. Short term and log term toxicity with mAb and cellular therapy demands thorough understanding of mechanism, biology behind the “ on target” and “off target” effects, side effect profile and their prevention. Further trials are warranted to determine best CAR-T cell construct and design for treating MM. Outcomes with many single agent mAb therapy were not encouraging and provide a rationale that future trials with mAbs should be done as multi-agent therapies. Promising results with isatuximab warrants further trials. Antibody-drug conjugate treatment is worth further evaluation both as single agent and in combination with standard anti-MM agents. Individualized treatment approach based on surface CD marker expression need to be developed and may produce better outcomes. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Updates from ICARIA-MM, a phase 3 study of isatuximab (Isa) plus pomalidomide and low-dose dexamethasone (Pd) versus Pd in relapsed and refractory multiple myeloma (RRMM).

8017 Background: Isa is an approved monoclonal antibody that binds to a specific epitope on the CD38 receptor. The Phase 3 ICARIA-MM study (NCT02990338) demonstrated significantly improved progression-free survival (PFS) with Isa-Pd vs Pd ( P= 0.001) and a manageable safety profile (Attal M, et al. Lancet 2019;394:2096-2107). Here we report updated ICARIA results. Methods: Pts with RRMM (N = 307) who have received ≥2 prior therapies, including lenalidomide (Len) and a proteasome inhibitor (PI), were randomized to Isa-Pd (n = 154) or Pd (n = 153). Isa was administered intravenously at 10 mg/kg weekly for 4 weeks, and every other week thereafter. This preplanned second interim analysis assessed longer term outcomes, including time to next treatment (TTNT), overall survival (OS), time from randomization to disease progression on first subsequent therapy or death (PFS2), and safety. Results: Pts had a median of 3 prior lines of therapy (IQR 2–4; table). As of Oct 1, 2020 (median follow-up, 35.3 months [mo]), 27 Isa-Pd pts (18%) vs 12 Pd pts (8%) were still on treatment; 60% vs 72% had proceeded to subsequent therapy. Median TTNT was 15.5 mo with Isa-Pd vs 8.9 mo with Pd (hazard ratio [HR] 0.56; 95% confidence interval [CI] 0.42–0.74; P&lt; 0.0001); 24% vs 58% of pts with subsequent therapy received daratumumab (dara). Overall response rate (ORR) in subsequent treatment with dara monotherapy was higher after Pd (38%) than Isa-Pd (14%), but was similar (32% vs 31%) with dara combination therapy (table). Median PFS2 in the intent-to-treat population was 17.5 mo with Isa-Pd vs 12.9 mo with Pd (HR 0.76; 95% CI 0.58–0.99; P= 0.0202). Median OS was 24.6 mo with Isa-Pd vs 17.7 mo with Pd (HR 0.76; 95% CI 0.58–1.01; one-sided P= 0.0280). Median treatment duration was 47.6 weeks (range 1.3–171.6) with Isa-Pd vs 24.0 weeks (range 1.0–168.6) with Pd. Serious treatment-emergent adverse event (TEAEs) were seen in 73% of Isa-Pd pts vs 60% of Pd pts. Most frequent non-hematologic TEAEs (any grade) with Isa-Pd were infusion reaction (38%), upper respiratory tract infection (34%), and diarrhea (30%). Grade 3–4 neutropenia (85% vs 71%) and thrombocytopenia (34% vs 25%) were more frequent with Isa-Pd than with Pd. Conclusions: Isa-Pd demonstrates a significant improvement in TTNT and PFS2 compared with Pd. A strong trend in OS benefit was also seen in the Isa-Pd arm, with approximately 7 mo improvement in median OS. The overall safety profile remains unchanged from prior analyses. Funding: Sanofi. Clinical trial information: NCT02990338. [Table: see text]

Dupilumab for children and adolescents with atopic dermatitis: An Asian perspective

Atopic dermatitis (AD) is a common, chronic, recurrent inflammatory skin disease. Poorly controlled AD can lead to reduced quality of life (QoL) and psychosocial impairment. Dupilumab is the first approved monoclonal antibody targeting type 2 inflammation, for adolescent and adult patients with moderate-to-severe AD. We performed a retrospective analysis of the efficacy and safety of dupilumab in a cohort of Asian children and adolescents with moderate-to-severe AD. Clinical response was documented with investigator global assessment (IGA) and eczema area and severity index (EASI) scores. Improvement in QoL was assessed using child dermatology life quality index (CDLQI) or Teenager's quality of life (T-QoL), and caregivers' QoL was assessed using dermatitis family impact (DFI) questionnaire. Twelve patients were recruited, aged between 6 to 18 years of age (mean 13.3 years), with mean duration of AD of 9.8 years. At baseline, the mean IGA score was four and the mean EASI was 48.2. The mean T-QoL and DFI scores at baseline were 18.7 and 19.6, respectively. After 12 to 16 weeks of treatment, the mean IGA score decreased to 2.2. The mean EASI decreased to 19.3 with mean reduction of 28.9. The mean T-QoL decreased to 7.5 with mean reduction of 11.2, and the mean DFI decreased to 8.6 with mean reduction of 11. Adverse events included mild conjunctivitis in two patients and paradoxical head and neck erythema in one patient. Our study supports dupilumab as an effective and safe treatment option for Asian children and adolescents with moderate-to-severe AD.

Risk of Postmarket Black Box Warnings in FDA Approved Monoclonal Antibodies

It is important for Allergists/Immunologists to understand the risks and benefits of monoclonal antibodies (mAbs), which include unknown future risks especially for recently approved mAbs. We sought to estimate the potential risk of a future postmarket black box warning (BBW) in FDA-approved mAbs.

Potent synergistic anti-tumor activity of a novel humanized anti-HER2 antibody hersintuzumab in combination with trastuzumab in xenograft models.

Immunotherapy of HER2-overexpressing cancers by FDA approved monoclonal antibodies (mAbs) such as trastuzumab and pertuzumab has shown promising results. We have recently produced a novel humanized anti-HER2 mAb, hersintuzumab, which did not sterically inhibit binding of trastuzumab and pertuzumab to HER2, thus recognizing a distinct epitope on subdomain I + II of HER2. In this study, we assessed the in vitro and in vivo anti-tumor activity of this mAb individually and in combination with trastuzumab. Different HER2-overexpressing human cancer cell lines, including SKOV3, NCI-N87 HCC1954 and BT-474 were cultured and binding reactivity of Hersintuzumab to these cell lines was analyzed by flow cytometry. In addition, the inhibitory effect of different concentrations of hersintuzumab, trastuzumab and their combination on tumor cells growth was assessed by XTT assay. For Assessment of tumor growth inhibition in xenograft model, Balb/c athymic nude mice were subcutaneously injected with NCI-N87 and SKOV3 tumor cells and then treated intravenously with these mAbs. Our results showed that hersintuzumab could bind to all HER2-overexpressing cell lines similar to trastuzumab. In vitro experiments showed that both hersintuzumab and trastuzumab individually and in combination inhibited growth of all cell lines with the exception of HCC-1954.Inhibitory effect of the combination of mAbs was significantly higher than that of each mAb alone. Similar results were obtained in the gastric (NCI-N87) and ovarian (SKOV-3) tumor xenograft models. Hersintuzumab in combination with trastuzumab induces synergic anti-tumor effects on HER2-overexpressing cells in vitro and in vivo and is potentially a therapeutic tool for treatment of HER2-overexpressing cancers.

Machine Learning Feature Selection for Predicting High Concentration Therapeutic Antibody Aggregation.

Protein aggregation can hinder the development, safety and efficacy of therapeutic antibody-based drugs. Developing a predictive model that evaluates aggregation behaviors during early stage development is therefore desirable. Machine learning is a widely used tool to train models that predict data with different attributes. However, most machine learning techniques require more data than is typically available in antibody development. In this work, we describe a rational feature selection framework to develop accurate models with a small number of features. We applied this framework to predict aggregation behaviors of 21 approved monospecific monoclonal antibodies at high concentration (150mg/mL), yielding a correlation coefficient of 0.71 on validation tests with only two features using a linear model. The nearest neighbors and support vector regression models further improved the performance, which have correlation coefficients of 0.86 and 0.80, respectively. This framework can be extended to train other models that predict different physical properties.

Depth of Response and Response Kinetics of Isatuximab Plus Carfilzomib and Dexamethasone in Relapsed Multiple Myeloma: Ikema Interim Analysis

Depth of Response and Response Kinetics of Isatuximab Plus Carfilzomib and Dexamethasone in Relapsed Multiple Myeloma: Ikema Interim Analysis

ANTI-HER2 ANTIBODIES IN COMBINATION WITH CHEMOTHERAPY OR CHEMOTHERAPY-FREE REGIMENS TARGETING HER2-POSITIVE BREAST CANCER: A SYSTEMATIC REVIEW

Breast cancer is the leading cause of cancer-related death in female worldwide. Human epidermal growth factor receptor 2 (HER2) amplification is observed in approximately 20% of breast cancer cases and is associated with poor clinical outcomes. Dual HER2 blockade without chemotherapy represents an attractive therapeutic approach, and it remains unresolved if anti-HER2 therapeutic antibodies are sufficient to replace chemotherapy regimens. In this review, we discuss the approved therapeutic monoclonal antibodies (pertuzumab and trastuzumab) and antibody-drug conjugate (trastuzumab emtansine or T-DM1) for the treatment of HER2-positive breast cancer patients. In summary, phase II and III clinical trials have demonstrated that dual HER2 blockade (pertuzumab and trastuzumab) plus chemotherapy regimens confer better efficacy compared with dual HER2 blockade alone, or anti-HER2 antibody monotherapy, in HER2-positive breast cancer patients. Dual HER2 blockade (pertuzumab and trastuzumab) combined with chemotherapies (5-fluorouracil, epirubicin, cyclophosphamide and docetaxel) yield superior response. Moreover, dual HER2 blockade (T-DM1 and pertuzumab) in combination with docetaxel represents a promising treatment regimen containing T-DM1. Ongoing clinical trials are assessing the optimal chemotherapy of choice with anti-HER2 antibodies combinations. In conclusion, improved outcomes are attributable to selection for the optimal chemotherapy regimen in combination with anti-HER2 antibodies instead of replacing chemotherapy altogether with the current line of anti-HER2 therapeutic antibodies.