<?xml version="1.0" encoding="UTF-8"?><rss version="2.0" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:wfw="http://wellformedweb.org/CommentAPI/" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:sy="http://purl.org/rss/1.0/modules/syndication/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" > <channel> <title>mmae – Creative Biolabs ADC Blog</title> <atom:link href="https://www.creative-biolabs.com/blog/adc/tag/mmae/feed/" rel="self" type="application/rss+xml" /> <link>https://www.creative-biolabs.com/blog/adc</link> <description>Antibody-Drug Conjugate (ADC) - Creative Biolabs</description> <lastBuildDate>Mon, 29 Jan 2024 06:03:49 +0000</lastBuildDate> <language>en-US</language> <sy:updatePeriod> hourly </sy:updatePeriod> <sy:updateFrequency> 1 </sy:updateFrequency> <generator>https://wordpress.org/?v=6.3.1</generator> <image> <url>https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2020/02/cropped-favicon-32x32.png</url> <title>mmae – Creative Biolabs ADC Blog</title> <link>https://www.creative-biolabs.com/blog/adc</link> <width>32</width> <height>32</height> </image> <item> <title>New Highlights of ADC Targeting Intracellular Antigens—TCRm-ADC</title> <link>https://www.creative-biolabs.com/blog/adc/new-highlights-of-adc-targeting-intracellular-antigens-tcrm-adc/</link> <dc:creator><![CDATA[bioadc]]></dc:creator> <pubDate>Mon, 29 Jan 2024 02:52:18 +0000</pubDate> <category><![CDATA[Antibody-drug Conjugates Research]]></category> <category><![CDATA[mmae]]></category> <category><![CDATA[TCRm-ADC]]></category> <guid isPermaLink="false">https://www.creative-biolabs.com/blog/adc/?p=605</guid> <description><![CDATA[Intracellular proteins can be degraded, processed, and presented on the cell surface in complex with MHC molecules (HLA), which can be specifically recognized by TCR (Figure 1). Antibodies that recognize pMHC like<a class="moretag" href="https://www.creative-biolabs.com/blog/adc/new-highlights-of-adc-targeting-intracellular-antigens-tcrm-adc/">Read More...</a>]]></description> <content:encoded><![CDATA[<p><span style="font-size: 15px;">Intracellular proteins can be degraded, processed, and presented on the cell surface in complex with MHC molecules (HLA), which can be specifically recognized by TCR (Figure 1). Antibodies that recognize pMHC like TCR are called TCR mimic antibodies (TCRm). Currently, there are research teams that have successfully developed high-affinity TCRm antibodies targeting multiple tumor targets presented by different HLA alleles. The antitumor characteristics of TCRm antibodies in preclinical models have been confirmed. However, their therapeutic effect is not very satisfactory. Therefore, considering the strategy of using TCRm to construct ADC may improve its clinical effect. In addition, it has been proven by teams that TCR mimic antibody-drug conjugates (TCRm-ADCS) exhibit good antitumor effects <em>in vitro</em> and <em>in vivo</em>.</span></p> <p><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-1.jpg"><img decoding="async" fetchpriority="high" class="aligncenter wp-image-614" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-1.jpg" alt="" width="379" height="312" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-1.jpg 550w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-1-300x247.jpg 300w" sizes="(max-width: 379px) 100vw, 379px" /></a><span style="font-size: 12px;">Figure 1. Peptide/human leukocyte antigen class I (HLA I) I complex as the targets of T cell receptor mimic antibody-drug conjugates (TCRm-ADCs) and bispecific(Bi)-TCRm-ADCs on the tumor cell surface (Shen Y, 2019)</span></p> <p><span style="font-size: 15px;">The WT1 cancer protein is an intracellular oncogenic transcription factor hardly expressed in normal adult tissues but overexpressed in various leukemias and solid cancers. The WT1-derived HLA-A*02:01 T-cell epitope RMFPNAPYL (RMF) is a verified target through T-cell immunotherapy.</span></p> <p><span style="font-size: 15px;">Here, two TCRm-ADCs (ESK-MMAE and Q2L-MMAE) were generated against the WT1 RMF/HLA-A*02:01 complex, which have different affinities and can mediate specific anti-tumor activity. Although ESK-MMAE showed a higher tumor growth inhibition rate <em>in vivo</em>, its efficacy is not that promising, which might be due to the low expression of pHLA targets. Therefore, the bispecific TCRm-ADC was also investigated, which has a more effective tumor cytotoxicity compared to the single TCRm-ADC. In conclusion, the results confirm the feasibility of using intracellular peptides as ADC targets, expanding the range of antigen choices for antibody drugs and providing a new strategy for precise treatment of tumors.</span></p> <h6><span style="font-size: 15px;">Preparation and <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/adc-pharmacokinetics-characterization.htm">characterization of TCRm antibodies</a></span></strong></span></h6> <p><span style="font-size: 15px;">Firstly, ESK and Q2L antibodies, which target the HLA-A*02:01 restricted WT1 RMF epitope, were separately expressed in 293F and 293T cells. They were subsequently purified by Protein A antibody affinity chromatography and their affinities were evaluated. The results revealed that the association constant (Ka) and dissociation constant (Kd) of ESK were higher than those of Q2L, indicating that the affinity of ESK (3.50 nM) outperforms Q2L. T2 cells are a cell line that are HLA-A0201 positive and TAP defective, lacking pMHC on their surfaces. Following exogenous addition of β2 microglobulin (β2m) and peptides, specific pMHC can form on the surface of T2 cells. K562-A2-WT1 126-134 is a genetically engineered cell line expressing HLA-A*02:01 and WT1, with WT1 RMF/HLA-A*02:01 complexes quantity on its surface being 2.4 x 103 copies per cell, whereas A431 is a HLA-A*02:01 and WT1 negative cell line, serving as the control.</span></p> <h6><span style="font-size: 15px;">Specific Srt A-mediated TCRm-ADC and its characterization</span></h6> <p><span style="font-size: 15px;">After site-specific conjugation mediated by sortase A, ESK-MMAE and Q2L-MMAE were purified by Protein A antibody affinity chromatography. The drug-antibody ratios (DAR) of ESK-MMAE and Q2L-MMAE were determined by reversed-phase high performance liquid chromatography (RP-HPLC), calculated based on the peak area ratio (DAR=((A L1 / (A L0 + A L1) + A H1 / (A H0 + A H1)) × 2). Interestingly, the DARs of both ESK-MMAE and Q2L-MMAE were 3.0. TCRm-ADC was able to bind with K562-A2-WT1 126-134 in a dose-dependent manner, implying that the higher the concentration, the more TCRm-ADC binds with the cell surface. Flow cytometry observed a slight reduction in the affinity of TCRm-ADC after conjugation.</span></p> <h6><span style="font-size: 15px;">Internalization of TCRm antibody and its conjugate</span></h6> <p><span style="font-size: 15px;">Internalization is the primary method through which ADCs kill cancer cells following antigen binding. Firstly, the internalization rates of two types of TCRm antibodies and their conjugates were detected by flow cytometry. As shown in Figure 2A, about 50%–65% of the TCRm antibodies and conjugates were internalized by K562-A2-WT1 126-134 after a 2-hour incubation. The <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/adc-internalization-assay.htm">internalizations</a></span></strong> of ESK-MMAE and Q2L-MMAE were slightly reduced after conjugation, which is consistent with the results of affinity evaluation.</span></p> <p><span style="font-size: 15px;">Moreover, the internalization of TCRm antibodies and their conjugates was verified via fluorescent confocal microscopy. TCRm antibodies or TCRm-ADCs are co-incubated with K562-A2-WT1 126-134, and labeled with Cy5-tagged human Fc antibodies and Cy3-tagged lysosomal associated membrane protein-1 (LAMP-1, a lysosomal marker). As shown in Figure 2B, both TCRm antibodies and TCRm-ADCs were observed in cells, indicating they can all be internalized by K562-A2-WT1 126-134. There is partial overlap of Cy5 and Cy3 fluorescence, suggesting that after internalization into the cells, TCRm antibodies and TCRm-ADCs can be transported to the lysosomes for degradation, thus releasing <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/monomethyl-auristatin-e-725.htm">MMAE molecules</a>.</span></strong></span></p> <p><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-2.jpg"><img decoding="async" class="aligncenter wp-image-615" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-2.jpg" alt="" width="295" height="363" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-2.jpg 632w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-2-243x300.jpg 243w" sizes="(max-width: 295px) 100vw, 295px" /></a></p> <p style="text-align: center;"><span style="font-size: 12px;">Figure 2. Cellular internalization of TCRm antibodies and their conjugates (Shen Y, 2019)</span></p> <p><span style="font-size: 15px;"><strong>View all MMAE-linker complex products</strong></span></p> <table style="height: 510px; width: 78.2762%; border-bottom: solid; margin: 0 auto;"> <tbody> <tr style="height: 13px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; background-color: #1f5cb8; height: 10px; text-align: center; vertical-align: middle;"><span style="color: #ffffff;"><strong>Cat.No.</strong></span></td> <td style="width: 236.717px; border-style: solid; border-color: #050505; background-color: #1f5cb8; height: 10px; text-align: center; vertical-align: middle;"><span style="color: #ffffff;"><strong>Product Name</strong></span></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; background-color: #1f5cb8; height: 10px; text-align: center; vertical-align: middle;"><span style="color: #ffffff;"><strong>Price</strong></span></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-005</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/mc-mmae-890.htm">Mc-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-005%5dMc-MMAE&cat=ADC-S-005">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-007</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/vc-mmae-892.htm">Vc-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-007%5dVc-MMAE&cat=ADC-S-007">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-008</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/osu-glu-vc-pab-mmae-893.htm">OSu-Glu-vc-PAB-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-008%5dOSu-Glu-vc-PAB-MMAE&cat=ADC-S-008">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-017</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/dbco-peg4-vc-pab-mmae-902.htm">DBCO-PEG4-vc-PAB-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-017%5dDBCO-PEG4-vc-PAB-MMAE&cat=ADC-S-017">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-025</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/mc-betaglucuronide-mmae-1-4659.htm">MC-betaglucuronide-MMAE-1</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-026%5dMC-betaglucuronide-MMAE-2&cat=ADC-S-026">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-026</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/mc-betaglucuronide-mmae-2-4660.htm">MC-betaglucuronide-MMAE-2</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-027%5dSGD-1910%20(Mc-Val-Ala-PBD%20)&cat=ADC-S-027">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-033</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/gly3-vc-pab-mmae-4667.htm">Gly3-vc-PAB-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-033%5dGly3-vc-PAB-MMAE&cat=ADC-S-033">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-060</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/mal-di-eg-val-cit-pab-mmae-4694.htm">MAL-di-EG-Val-Cit-PAB-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/form/order?n=%5bADC-S-060%5dMAL-di-EG-Val-Cit-PAB-MMAE&cat=ADC-S-060">Inquiry</a></span></strong></td> </tr> <tr style="height: 52px;"> <td style="width: 113.151px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;">ADC-S-073</td> <td style="width: 236.717px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/mdpr-val-cit-pab-mmae-4707.htm">mDPR-Val-Cit-PAB-MMAE</a></span></strong></td> <td style="width: 86.1085px; border-style: solid; border-color: #050505; height: 10px; text-align: center; vertical-align: middle;"><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="/adc/form/order?n=%5bADC-S-073%5dmDPR-Val-Cit-PAB-MMAE&cat=ADC-S-073">Inquiry</a></span></strong></td> </tr> </tbody> </table> <h6><em>In vitro</em> anti-tumor activity of TCRm-ADC</h6> <p><span style="font-size: 15px;">WT1 RMF/HLA-A*02:01 complex positive and negative cell lines were co-incubated with ESK-MMAE and Q2L-MMAE for 96 hours. Interestingly, compared with negative cells (A431), ESK-MMAE and Q2L-MMAE showed specific killing effects on K562-A2-WT1 126-134 (Figure 3). Although the affinity of ESK-MMAE is higher than that of Q2L-MMAE, both TCRm-ADCs show similar anti-tumor activity against K562-A2-WT1 126–134, and the IC 50 of ESK-MMAE and Q2L-MMAE are 7 and 9 μg/mL, respectively, which may be caused by the quantity of pHLA on the surface of K562-A2-WT1 126-134 cells.</span></p> <p><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-3.jpg"><img decoding="async" class="aligncenter wp-image-616" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-3.jpg" alt="" width="392" height="502" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-3.jpg 530w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-3-234x300.jpg 234w" sizes="(max-width: 392px) 100vw, 392px" /></a></p> <p style="text-align: center;"><span style="font-size: 12px;">Figure 3. Antitumor activity and toxicity of TCRm-ADCs (Shen Y, 2019)</span></p> <h6><span style="font-size: 15px;"><em>In vivo</em> efficacy evaluation of TCRm-ADC</span></h6> <p><span style="font-size: 15px;">Firstly, a xenograft model of K562-A2-WT1 126-134 leukemia was established in BALB/c nude mice, followed by the administration of TCRm or TCRm-ADC, with anti-CD20-ADC (Ofatumumab (OFA)-MMAE) used as a negative control. As shown in Figure 3B, the average tumor volume of the PBS group and the OFA-MMAE group (15 mg/kg) quickly reached 3000 mm3, and there was no significant difference in the average tumor volume between the two groups. In contrast, Q2L-MMAE and ESK-MMAE (15 mg/kg) significantly delayed tumor growth, suggesting that Q2L-MMAE and ESK-MMAE exhibited specific antitumor activities <em>in vivo</em>. Also, the phenomenon of rapid tumor growth after the termination of TCRm-ADCs treatment indicated that the two TCRm-ADCs possess tumor suppressive functions. Moreover, the antitumor activity of ESK-MMAE was significantly superior to Q2L-MMAE.</span></p> <p><span style="font-size: 15px;">Meanwhile, changes in body weight were monitored to assess the <span style="color: #0000ff;"><strong><a style="color: #0000ff;" href="/adc/adc-in-vivo-analysis.htm"><em>in vivo</em> toxicity of TCRm-ADC</a></strong></span>. Although a slight decline was noted in the relative body weight of all groups, the change in weight for mice treated with TCRm-ADC was smaller than that for mice treated with PBS, suggesting that mouse weight was largely influenced by the tumor burden. For a systemic toxicity evaluation, mice were euthanized 10 days after drug administration and the histological sections of major organs (heart, liver, kidney, and lung) were examined after staining with hematoxylin and eosin. No obvious histopathological changes were observed in the organ sections (Figure 4.). These results suggest that ESK-MMAE and Q2L-MMAE exhibit antitumor activity without any visible toxicity.</span></p> <h6>Preparation and Characterization of Bi-TCRm-ADC</h6> <p><span style="font-size: 15px;">To enhance the efficacy of TCRm-ADC, the “knob-to-holes” approach (which improves the success rate of non-homotypic antibody chain assembly) was used to generate double specific complex IgG against the WT1 RMF/HLA-A02:01 complex and NY-ESO-1 SLL/HLA-A 02:01 (Figure 5A). Following co-transfection of 293F cells with “knob” and “hole” plasmids, the bi-TCRm antibody was purified through Protein A antibody affinity chromatography and Ni-NTA affinity chromatography, which yielded a purified stable heterodimer.</span></p> <h6><span style="font-size: 15px;">Internalization and <em>in vitro</em> cytotoxicity of Bi-TCRm-ADC</span></h6> <p><span style="font-size: 15px;">The internalization efficiency of ESK-1G4-MMAE was slightly lower than that of ESK-1G4 and ESK-MMAE, but significantly higher than that of 1G4113-4-MMAE (Figure 4A). In addition, the subcellular transport and localization of ESK-1G4-MMAE in K562-A2-NY-ESO-1 157-165 were further determined by fluorescence confocal microscopy (Figure 4B). After incubating with cells for 4 hours, ESK-1G4-MMAE was located inside the cytoplasm, indicating internalization. Furthermore, the internalized ESK-1G4-MMAE co-localized with LAMP-1, suggesting that ESK-1G4-MMAE can be transported to lysosomes to release MMAE molecules after internalization.</span></p> <p><span style="font-size: 15px;">In the in-vitro antitumor activity study, ESK-1G4-MMAE demonstrated stronger efficacy against K562-A2-NY-ESO-1 157-165 compared to ESK-MMAE and 1G4113-4-MMAE (Figure 4C). This suggests that the antitumor activity of TCRm-ADC can be effectively improved by constructing bispecific antibodies to increase epitope binding density.</span></p> <p><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-4.jpg"><img decoding="async" loading="lazy" class="aligncenter wp-image-617" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-4.jpg" alt="" width="372" height="292" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-4.jpg 542w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2024/01/a202401-4-300x235.jpg 300w" sizes="(max-width: 372px) 100vw, 372px" /></a></p> <p style="text-align: center;"><span style="font-size: 12px;">Figure 4. Internalization and <em>in vitro</em> cytotoxicity of ESK-1G4-MMAE (Shen Y, 2019)</span></p> <h6><span style="font-size: 15px;">WT1 Protein Epitope Peptide Prediction</span></h6> <p><span style="font-size: 15px;">In order to find the potential presentation peptides of WT1 protein, we used the online prediction algorithm to predict the epitope peptides of WT1 protein. According to the NetMHC binding prediction algorithm, there are 12 WT1 protein candidate peptides with a length of 8–11 and a suitable affinity with HLA-A*02:01. Subsequently, these 12 peptides were validated in terms of the human proteasome cutting site and TAP transport efficiency in NetCTL. Apart from the RMF epitope peptide, other WT1 protein peptides could potentially be presented by HLA I class molecules as targets for cancer treatment, reflecting the advantage of the epitope diversity of Bi-TCRm-ADC.</span></p> <p><span style="font-size: 15px;">The enhanced potency of Bi-TCRm-ADC represents a promising strategy to enhance the anti-tumor action of TCRm-ADC. These new generations TCRm-ADC and Bi-TCRm-ADC will expand the use of intracellular cancer proteins and ADCs.</span></p> <p><span style="font-size: 12px;">Reference</span></p> <p><span style="font-size: 12px;">Shen Y, Li Y M, Zhou J J, et al. The antitumor activity of TCR-mimic antibody-drug conjugates (TCRm-ADCs) targeting the intracellular Wilms tumor 1 (WT1) oncoprotein[J]. International Journal of Molecular Sciences, 2019, 20(16): 3912.</span></p> ]]></content:encoded> </item> <item> <title>The Success of Seattle Genetics/Wutian ADC Adcetris for Phase III Clinical Surgery of Peripheral T Cell Lymphoma (PTCL)</title> <link>https://www.creative-biolabs.com/blog/adc/antibody-drug-conjugate-adcetris/</link> <dc:creator><![CDATA[bioadc]]></dc:creator> <pubDate>Fri, 26 Oct 2018 03:59:50 +0000</pubDate> <category><![CDATA[Antibody-drug Conjugates Research]]></category> <category><![CDATA[News]]></category> <category><![CDATA[adc clinical trials]]></category> <category><![CDATA[adc research]]></category> <category><![CDATA[Adcetris]]></category> <category><![CDATA[antibody drug conjugates]]></category> <category><![CDATA[mmae]]></category> <category><![CDATA[protease-sensitive crosslinker]]></category> <guid isPermaLink="false">https://www.creative-biolabs.com/blog/adc/?p=163</guid> <description><![CDATA[October 03, 2018 – Seattle Genetics and Takeda recently announced the evaluation of antibody conjugates Adcetris (brentuximab vedotin) for the treatment of peripheral T-cell lymphoma (PTCL, also known as mature Phase III<a class="moretag" href="https://www.creative-biolabs.com/blog/adc/antibody-drug-conjugate-adcetris/">Read More...</a>]]></description> <content:encoded><![CDATA[<p><span style="font-size: 15px;">October 03, 2018 – Seattle Genetics and Takeda recently announced the evaluation of antibody conjugates Adcetris (brentuximab vedotin) for the treatment of peripheral T-cell lymphoma (PTCL, also known as mature Phase III clinical study of T-cell lymphoma, MTCL) reached the primary endpoint of ECHELON-2. Based on data of the research, Seattle Genetics has planned to submit Adcetris’ Supplementary Biological License (sBLA) to the US FDA in the near future.</span><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/10/Adcetris-adc.jpg"><img decoding="async" loading="lazy" class="size-full wp-image-173 aligncenter" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/10/Adcetris-adc.jpg" alt="" width="600" height="350" /></a></p> <h6>PTCL Clinal Program Introduction</h6> <p><span style="font-size: 15px;">ELON-2 is the largest randomized, double-blind, phase III study to date in PTCL patients enrolled in previously untreated CD30-positive PTCL patients, which evaluated for Adcetris in combination with chemotherapy regimen CHP (cyclophosphamide + A) and the efficacy and safety of CHOP (cyclophosphamide + doxorubicin + vincristine + prednisone) in first-line treatment compared to the currently accepted first-line standard care regimen for PTCL. The primary endpoint of the study was progression-free survival (PFS) assessed by the Independent Review Body (IRF).</span></p> <p><span style="font-size: 15px;">The results of the study showed that the Adcetris+CHP regimen achieved a statistically significant improvement in PFS (HR=0.71, p=0.0110) compared to the CHOP regimen, reaching the primary endpoint of the study. In addition, the Adcetris+CHP regimen also demonstrated superiority in key secondary endpoint overall survival (OS) compared to the CHOP regimen (HR=0.66, p=0.0244). In other key secondary endpoints, the Adcetris+CHP regimen also showed statistically significant advantages, including: PFS, complete response rate (CRR), and objective response rate (ORR) in patients with intersystem degenerative large cell lymphoma (sALCL). In this research, the Adcetris+CHP scheme has comparable security to the CHOP scheme. Detailed data will be announced at the annual meeting of the American Society of Hematology (ASH) in early December.</span></p> <h6>Antibody-drug Conjugate (Adcetris)</h6> <p><span style="font-size: 15px;">Adcetris is an <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/services.htm">antibody-conjugated drug (ADC) </a></span></strong>that is coupled by a monoclonal antibody that targets the CD30 protein and a microtubule disrupter (<span style="color: #0000ff;"><strong><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/auristatins.htm">monomethyl auristatin E, MMAE</a></strong></span>) via a <span style="color: #0000ff;"><strong><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/peptide-linker.htm">protease-sensitive crosslinker</a></strong></span>. The coupling technology is the proprietary technology of Seattle Genetics. CD30 protein is a clear marker of classical Hodgkin’s lymphoma (HL) and systemic anaplastic large cell lymphoma (sALCL), while Auristatin E blocks cell division by inhibiting the polymerization of tubulin. Adcetris is stable in the blood and releases MMAE after internalization by CD30-positive tumor cells.</span></p> <p><span style="font-size: 15px;">Adcetris was developed by Seattle Genetics, and in 2009, Takeda reached a licensing agreement and obtained commercial rights to the drug in other countries except the US and Canada. By far, Adcetris has been approved by more than 70 countries around the world.</span></p> <p><span style="font-size: 15px;">Currently, Takeda and Seattle Genetics are actively promoting a large phase III clinical development project to make Adcetris as a basic care drug for the treatment of CD30-positive lymphoma and to redefine the clinical first-line treatment of lymphoma.</span></p> ]]></content:encoded> </item> <item> <title>Seattle Genetics Launched the Phase II Clinical Trial of Antibody-drug Conjugate (ADC) Called Enfortumab Vedotin</title> <link>https://www.creative-biolabs.com/blog/adc/adc-called-enfortumab-vedotin/</link> <dc:creator><![CDATA[bioadc]]></dc:creator> <pubDate>Sat, 01 Sep 2018 07:55:16 +0000</pubDate> <category><![CDATA[Antibody-drug Conjugates Research]]></category> <category><![CDATA[News]]></category> <category><![CDATA[antibody-drug conjugate]]></category> <category><![CDATA[CD48-targeting monoclonal antibody molecule]]></category> <category><![CDATA[enfortumab vedotin]]></category> <category><![CDATA[mmae]]></category> <guid isPermaLink="false">https://www.creative-biolabs.com/blog/adc/?p=119</guid> <description><![CDATA[Seattle Genetics and its partner, Astellas, have recently announced that the patients were selected for EV-201, the key phase II clinical trial of an experimental antibody-drug conjugate (ADC) called enfortumab vedotin. The<a class="moretag" href="https://www.creative-biolabs.com/blog/adc/adc-called-enfortumab-vedotin/">Read More...</a>]]></description> <content:encoded><![CDATA[<p><span style="font-size: 15px;">Seattle Genetics and its partner, Astellas, have recently announced that the patients were selected for EV-201, the key phase II clinical trial of an experimental <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/services.htm">antibody-drug conjugate</a> </span></strong>(ADC) called <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/pdf/adc-w-2396.pdf">enfortumab vedotin</a></span></strong>. The study was conducted in patients with locally advanced or metastatic urothelial carcinoma (UC) who had previously undergone checkpoint inhibitor (CPI) treatment. The efficacy and safety data from the first cohort of the study will be available in the first half of 2019 and will help enfortumab vedotin pass the regulatory application through Accelerated Approval designation of the US FDA.</span></p> <p><span style="font-size: 15px;">In addition, the two sides also announced that the first patient in the Phase III clinical study EV-301 has received treatment. It is a global randomized study conducted in previously treated patients with locally advanced or metastatic UC, and data from this study will be used for a broader global regulatory application.</span></p> <p><span style="font-size: 15px;">In the United States, the FDA has granted the Breakthrough Therapy to enfortumab vedotin for the treatment of patients with locally advanced or metastatic UC who has previously received CPI therapy. Apart from EV-201 and EV-301, the two sides are also conducting a phase I clinical study (EV-103), which combines enfortumab vedotin with Merck’s PD-1 immunotherapy Keytruda (pembrolizumab) for first-line treatment of patients with locally advanced or metastatic UC who is not suitable for cisplatin chemotherapy. Meanwhile, both parties are also evaluating enfortumab vedotin for other solid tumors, including ovarian cancer and non-small cell lung cancer.</span></p> <p><span style="font-size: 15px;">Enfortumab vedotin is an experimental ADC drug linked by a monoclonal antibody targeting the nectin-4 protein and a microtubule disruptor vedotin (<strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/auristatins.htm">MMAE</a></span></strong>) via Seattle Genetics’ proprietary conjugated technology. Enfortumab vedotin targeting the Nectin-4 protein is a cell adhesion molecule discovered by Astellas that acts as an ADC target and is expressed in many solid tumors.</span></p> <p><span style="font-size: 15px;">ADC is a new class of therapeutic drugs that is receiving increasing attention from pharmaceutical companies worldwide. ADC drugs are potent anticancer drugs targeting cancer cell conjugated by monoclonal antibodies and toxic drugs through biologically active linkers. The drug effect is greatly improved and the side effects are reduced by accurately identifying targets while leaving non-cancer cells unaffected.</span></p> <p><span style="font-size: 15px;"><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/09/antibody-drug-conjugate.jpg"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-121" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/09/antibody-drug-conjugate.jpg" alt="antibody drug conjugates" width="382" height="364" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/09/antibody-drug-conjugate.jpg 382w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/09/antibody-drug-conjugate-300x286.jpg 300w" sizes="(max-width: 382px) 100vw, 382px" /></a></span></p> <p><span style="font-size: 15px;">In March of this year, Seattle Genetics announced the advancement of an innovative ADC drug, the SGN-CD48A, for clinical development. The SGN-CD48A incorporates the company’s latest ADC technology innovation, a new generation of polyethylene glycol glucoside linkers, to improve drug stability in the blood circulation system, reduce off-target absorption, and enable each <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/target-cd2-115.htm">CD48-targeting monoclonal antibody molecule</a></span></strong> conjugated to more disrupted microtubule cytotoxic agent MMAE. And the drug can release a larger amount of MMAE after being internalized by CD48-positive tumor cells, while MMAE can block cell division by inhibiting the polymerization of tubulin. With this novel linker, SGN-48A has demonstrated potent antitumor activity in preclinical studies.</span></p> ]]></content:encoded> </item> <item> <title>Antibody–drug Conjugates: Historical Developments</title> <link>https://www.creative-biolabs.com/blog/adc/antibody-drug-conjugates-developments/</link> <dc:creator><![CDATA[bioadc]]></dc:creator> <pubDate>Fri, 11 May 2018 07:13:12 +0000</pubDate> <category><![CDATA[Antibody-drug Conjugates Research]]></category> <category><![CDATA[adc research]]></category> <category><![CDATA[antibody drug conjugates]]></category> <category><![CDATA[FDA approved ADC]]></category> <category><![CDATA[mmae]]></category> <category><![CDATA[PtLnX]]></category> <guid isPermaLink="false">https://www.creative-biolabs.com/blog/adc/?p=78</guid> <description><![CDATA[A Simple Concept of Antibody-drug Conjugates (ADCs) Developing new anticancer chemotherapeutic drugs showing superior antitumor efficacy with reduced toxicity is continuing to be a challenging endeavor. Antibody-drug conjugates (ADCs) are an emerging<a class="moretag" href="https://www.creative-biolabs.com/blog/adc/antibody-drug-conjugates-developments/">Read More...</a>]]></description> <content:encoded><![CDATA[<p><strong><span style="font-size: 18px;">A Simple Concept of Antibody-drug Conjugates (ADCs)</span></strong></p> <p><span style="font-size: 15px;">Developing new anticancer chemotherapeutic drugs showing superior antitumor efficacy with reduced toxicity is continuing to be a challenging endeavor. Antibody-drug conjugates (ADCs) are an emerging class of targeted anticancer drug delivery agent that confer selective and sustained cytotoxic drug delivery to tumors. More than a century ago, in 1906, Paul Ehrlich came up with the original concept of linking a cytotoxic payload to a protein with affinity and selectivity to a tumor, like an antibody (Ab) to achieve selective delivery of chemotherapeutic agents in a tumoral environment. Thus, the idea of antibody–drug conjugates (ADC) was born (Figure. 1).</span></p> <p><span style="font-size: 15px;"><img decoding="async" loading="lazy" class="size-full wp-image-79 aligncenter" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/basic-earlyantibody-drug-conjugate-concept-illustration.png" alt="basic earlyantibody-drug conjugate concept illustration" width="612" height="428" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/basic-earlyantibody-drug-conjugate-concept-illustration.png 612w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/basic-earlyantibody-drug-conjugate-concept-illustration-300x210.png 300w" sizes="(max-width: 612px) 100vw, 612px" /></span></p> <p style="text-align: center;">Figure. 1 Basic early antibody-drug conjugate concept illustration. (A) An antibody specific to a tumor-associated antigen recognizes the cell surface of a tumor cell, leaving normal tissue untouched. Then, drug release and action through various mechanisms leading to cell death. (B) In comparison, the free drug is toxic against both normal and cancer tissues, therefore, showing no selectivity between tumors and healthy tissue.</p> <p><span style="font-size: 15px;">Many monoclonal Ab (mAb), such as avastin, rituximab, and cetuximab, are well known as standard treatments for solid tumors and hematological cancers. By contrast, pristine chemodrugs, such as vinblastine, doxorubicin, and paclitaxel, have limited use for cancer treatment because of their nonspecific toxicity, thus narrowing the therapeutic window and increasing drug resistance. Discovery of ADCs bridged the gap between the Ab and cytotoxic drug, creating highly specific anticancer agents with an improved therapeutic window. This simple concept was thought to be a particularly attractive solution to the challenge of finding a way to increase the therapeutic window of the cytotoxic agent. Furthermore, conjugation of a small molecular weight cytotoxic agent to a large hydrophilic antibody is expected to restrict penetration of the cytotoxic compound across cellular membranes of antigen-negative normal cells, providing an additional mechanism by which the therapeutic index of the small molecule cytotoxin is widened, beyond that of targeted delivery (Figure. 2).</span></p> <p><span style="font-size: 15px;"><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/increasing-therapeutic-index.png"><img decoding="async" loading="lazy" class="size-full wp-image-80 aligncenter" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/increasing-therapeutic-index.png" alt="increasing therapeutic index" width="628" height="399" srcset="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/increasing-therapeutic-index.png 628w, https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/05/increasing-therapeutic-index-300x191.png 300w" sizes="(max-width: 628px) 100vw, 628px" /></a></span></p> <p style="text-align: center;">Figure. 2 Increasing the therapeutic index of cytotoxic drugs by conjugation to antibodies.</p> <p><strong><span style="font-size: 18px;">Advances in ADC Development</span></strong></p> <p><strong><span style="font-size: 15px;">First-generation ADCs</span></strong></p> <p><span style="font-size: 15px;">Since the breakthrough discovery of the first FDA-approved ADC, gemtuzumab ozogamicin (trade name, Mylotrag), anticancer therapy research has diversified, resulting in the development of several novels, safer ADCs. Advances in the development of ADCs towards targeted anticancer drug delivery is described by Creative Biolabs here. After the first generation of ADC had caused acute adverse effects and morbidity in patients, several parameters were pointed out that cannot be bypassed while developing an ADC:</span></p> <p><span style="font-size: 15px;">What We Learned From First-generation ADCs</span></p> <ul> <li>Insufficient potency of ADC in patients: due to low concentrations of antibody both in serum and moreover in tumor environment. The low concentration of mAb in plasma cannot allow to achieve the appropriate therapeutic range, and only <1% of the injected dose is able to reach the tumor localization.</li> <li>Nature of the antibody: nonhuman antibodies were used in first ADC, leading for example to an immune response through the generation of human anti-murine antibodies (HAMA), preventing repeated exposure of the ADC to patients, thus limiting its efficacy.</li> <li>Linker stability: first linkers were designed to be cleaved under acidic conditions, nevertheless this kind of linker proved to be quite unstable even in plasma, leading to unexpected toxicity due to the early uncontrolled release of the toxic payload.</li> <li>Limited expression of the antigen: before delivering and releasing the payload inside the cancer cell, the ADC should first bind to its specific antigen at the tumor cell surface. Because of the limited expression of this antigen at the surface, which should be of an average of 10,000 receptors per cancer cell, the ADC can only deliver a limited number of payloads that could be insufficient to reach the necessary concentration to achieve cell death.</li> <li>Limited internalization: not all the targeted antigen can allow an optimal clathrin dependent internalization of the antigen-mAb complex.</li> <li>Optimized average DAR = 4: this value should be the best one to achieve in order to build an optimized ADC, having in mind the compromise between a sufficient number of carried drugs and a limited modification of the native structure of the mAb.</li> </ul> <p> </p> <p><strong><span style="font-size: 15px;">Second-generation ADCs</span></strong></p> <p><span style="font-size: 15px;">The limitations and failures of first-generation ADCs were eliminated in second-generation ADCs. The premature release of drugs because of the unstable hydrazone linker in Mylotrag® has been avoided in second-generation FDA approved ADCs, by using different linkers, such as the valine-citrulline (cathepsin cleavable) linker in Adcetris® and a thioester (noncleavable) linker in Kadcyla ®. The cytotoxic payloads used in second-generation ADCs are also more potent than in first-generation ADCs. For example, tubulin-targeting agents, such as <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/blog/adc/payload-adc-mmae-mmaf/">MMAE</a></span></strong> used in Adcetris® is approximately 100–1000-fold stronger than DNA-intercalating doxorubicin of BR96 Dox. The IC50 of MMAE is approximately 1 nM in different human cancer cell lines, whereas doxorubicin IC50 is in the 1–6 uM range. Despite the improvement in cytotoxic payloads and the introduction of stable linkers, second-generation ADCs have significant limitations in terms of their heterogeneous DAR, resulting from stochastic coupling strategies between the Ab and drug. Typically, chemical conjugation between the drug and antibody occurs via the lysine or cysteine residue of the mAb, which generates DAR (range 0–8) with an average value of 3–4. Therefore, heterogeneous ADCs can contain a mixture of unconjugated, partially conjugated, and overconjugated antibodies and, therefore, there will be competition between unconjugated antibodies and drug-conjugated species for antigen binding that can diminish the activity of the ADC. By contrast, overconjugation of the drug to the Ab can result in antibody aggregation, a decrease in stability, and incremental increases in nonspecific toxicity, and a reduction in the half-life of ADCs in the circulation. Overall, heterogeneous ADCs have a limited therapeutic index and tumor penetration abilities, which are associated with the induction of drug resistant in the tumor microenvironment.</span></p> <p><span style="font-size: 15px;">What We Learned From Second-generation ADCs</span></p> <ul> <li>Mode of action and potency of the payload: only DNA alkylating agents and tubulin polymerization inhibitors with subnanomolar activities proved to be useful for targeted delivery through ADC technology, due to limited antigen expression and limited delivered amount of ADC available in the tumor. Such drug cannot be used in monotherapy due to high cytotoxicity and narrow therapeutic window.</li> <li>Nature of the linker and delivery mechanism: cleavable linkers finally have a broader efficacy than noncleavable ones. Indeed, although ADC incorporating either cleavable or noncleavable linker requires internalization to release the free drug, ADCs with cleavable linkers may also be active even when they are poorly internalized. The explanation can be found in the overexpression of some intracellular enzymes, like cathepsin B, that can leave lysosomes then cytosol to reach the extracellular media to promote metastasis or cell invasion, leading to cleavage of the linker in extracellular matrix, the free drug subsequently permeates the cell to reach its target [16].</li> <li>Conjugation site on the mAb: it can also affect potency, stability and PK properties of the ADC.</li> <li>Parameters to choose a good AG target: homogeneity/heterogeneity of tumor expression, high level of expression inside a tumor and selective expression for tumor tissues should be all well assessed for a given AG to be considered as a suitable target for ADC payload delivery.</li> </ul> <p><strong><span style="font-size: 15px;">Third-generation ADCs</span></strong></p> <p><span style="font-size: 15px;">The aforementioned concerns regarding the heterogeneous DARs of second-generation ADCs have been addressed in third-generation ADCs. Site-specific conjugation has been introduced to produce homogenous ADCs with well-characterized DARs and desired cytotoxicities [62]. The site-specific conjugation of the drug to Ab provides a single isomer ADC with a uniform DAR value. Such ADCs can be made using bioengineered antibodies containing site-specific amino acids, such as cysteine, glycan, or peptide tags [63]. For example, precise site-specific conjugation of MMAE to human IgG was developed by replacing the Ala114 amino acid of the CH1 domain of the IgG with cysteine to create a selectively engineered antibody, called <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/EnCys-mAb-based-conjugation.htm">THIOMAB</a></span></strong>. Alternative approaches to site-specific drug conjugation include: (i) a thio-bridge approach that links drugs to the interchain disulfide bond of Abs (four per mAb) [14]; (ii) introduction of unnatural amino acids, such as p-acetylphenylalanine, or noncanonical amino acids. Based on above techniques, Creative Biolabs has developed a novel ADC conjugation platform-<strong>P<strong>tLnX<img src="https://s.w.org/images/core/emoji/14.0.0/72x72/2122.png" alt="™" class="wp-smiley" style="height: 1em; max-height: 1em;" /></strong></strong><strong>. </strong><strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/ptlnx.htm">PtLnX</a></span> </strong>is a technical platform developed by <strong>Creative Biolabs</strong> and one of our collaborators that uses bis(ethylenediamine) platinum chloride [Pt(en)Cl<sub>2</sub>] as a linker core for ADC development.</span></p> <p><span style="font-size: 15px;">Wisely chosen targeted antigen, novel linker technology and original mode of drug action continue to be investigated to fully optimized ADC-based targeted therapy in order to improve the therapeutic index of an overall ADC. Extensive research is ongoing to improve all the components of ADCs that can enhance their targetability and therapeutic efficacy against tumors. A better understanding of ADC-targeting strategies can speed up the FDA approval rate of ADCs and drastically increase the number of clinical trials, especially in solid tumors.</span></p> <p><strong> </strong></p> <p> </p> ]]></content:encoded> </item> <item> <title>Payload of Antibody-drug Conjugates (ADCs) — MMAE and MMAF Brief Introduction</title> <link>https://www.creative-biolabs.com/blog/adc/payload-adc-mmae-mmaf/</link> <dc:creator><![CDATA[bioadc]]></dc:creator> <pubDate>Thu, 29 Mar 2018 07:28:39 +0000</pubDate> <category><![CDATA[Antibody-drug Conjugates Research]]></category> <category><![CDATA[antibody drug conjugates]]></category> <category><![CDATA[auristatin]]></category> <category><![CDATA[mmae]]></category> <category><![CDATA[mmaf]]></category> <category><![CDATA[monomethyl auristatin E]]></category> <category><![CDATA[monomethyl auristatin F]]></category> <category><![CDATA[payloads]]></category> <guid isPermaLink="false">https://www.creative-biolabs.com/blog/adc/?p=67</guid> <description><![CDATA[The concept of antibody–drug conjugates (ADCs) is based on exploiting the high specificity of a monoclonal antibody toward a selected tumor cell-surface antigen and enhancing the cell-killing capacity of the antibody by<a class="moretag" href="https://www.creative-biolabs.com/blog/adc/payload-adc-mmae-mmaf/">Read More...</a>]]></description> <content:encoded><![CDATA[<p><span style="font-size: 15px;">The concept of antibody–drug conjugates (ADCs) is based on exploiting the high specificity of a monoclonal antibody toward a selected tumor cell-surface antigen and enhancing the cell-killing capacity of the antibody by attaching a highly cytotoxic agent. An ADC can be divided into three main structural units (Fig. 1): the antibody (targets cancer marker); the linker (connect antibody and agent or drug); and the cytotoxic agent or drug (destroys target cells). To develop a successful antibody-drug conjugates (ADCs), every part needs to be selected carefully and many factors are taken into account. As common payloads of ADCs, MMAE (monomethyl auristatin E) and MMAF (monomethyl auristatin F) are both synthetic auristatin derivatives. <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/auristatins.htm">Auristatin</a></span></strong> is a dolastatin 10-based auristatin analog. Dolastatin 10 was initially isolated from the sea hare <em>Dolabella auricularia </em>at a vanishingly low yield (~ 1 mg from each 100 kg). It is a unique linear pentapeptide comprising of several unusual amino acids (Fig. 2)</span></p> <p style="text-align: center;"><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/03/antibody-design-and-construction.jpg"><img decoding="async" loading="lazy" class="size-full wp-image-68 aligncenter" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/03/antibody-design-and-construction.jpg" alt="antibody design and construction" width="500" height="825" /></a>Fig 1 Antibody-drug Conjugates (ADCs)</p> <p><span style="font-size: 15px;">Both MMAE and MMAF are peptide analogs, which have limited impact on the physicochemical properties of the mAbs. MMAF differs from MMAE owing to a phenylalanine moiety at its C-terminus, contributing to its membrane impermeability. MMAE and MMAF are both highly stable molecules, showing no signs of degradation in plasma, human liver lysosomal extracts, or proteases such as cathepsin B. As free toxins, the cytotoxicity of MMAE and MMAF is about 200- and 1000-fold less potent than that of dolastatin 10 in lymphoma cells, respectively.</span><br /> <span style="font-size: 15px;"></p> <p style="text-align: center;"><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/03/MMAE-and-MMAF.png"><img decoding="async" loading="lazy" class="size-full wp-image-69 aligncenter" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/03/MMAE-and-MMAF.png" alt="MMAE and MMAF" width="500" height="596" /></a>Fig. 2 Structures of dolastatin 10, MMAE, and MMAF. MMAE monomethyl auristatin-E, MMAF monomethyl auristatin-F</p> <p></span></p> <p><span style="font-size: 15px;"><span style="font-size: 15px;"><strong>Mode of Action (MOA) – MMAE and MMAF</strong></span></p> <p><span style="font-size: 15px;">MMAE and MMAF function as mitotic inhibitors. MMAE is an antimitotic synthetic agent that inhibits cellular division via inhibition of tubulin polymerization. Monomethyl auristatin F (MMAF), which also inhibits cellular division via inhibition of tubulin polymerization, has attenuated activity compared to MMAE due to the presence of a charged C-terminal phenylalanine. Taking a typical auristatin-based ADCs – brentuximab vedotinas as an example, MOA of MMAE is showed as the figure 3. Learn more about <span style="color: #000000;"><span style="color: #0000ff;"><strong><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/auristatins.htm">MOA of auristatin</a></strong></span>.</span></span></p> <p style="text-align: center;"><a href="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/03/Mechanism-of-action-of-brentuximab-vedotin-Abbreviation-HRS-Hodgkin-Reed-Sternberg.jpg"><img decoding="async" loading="lazy" class="aligncenter size-full wp-image-70" src="https://www.creative-biolabs.com/blog/adc/wp-content/uploads/2018/03/Mechanism-of-action-of-brentuximab-vedotin-Abbreviation-HRS-Hodgkin-Reed-Sternberg.jpg" alt="Mechanism-of-action-of-brentuximab-vedotin-Abbreviation-HRS-Hodgkin-Reed-Sternberg" width="500" height="662" /></a>Fig. 3 Mechanism of action of brentuximab vedotin (Adcetris). Adcetris is approved by the FDA in August 2011 against Hodgkin and anaplastic large cell lymphomas</p> <p><span style="font-size: 15px;"><strong>FDA-approved auristatin-based ADCs and Related Clinical Trials</strong></span></p> <p><span style="font-size: 15px;">Currently, there are four antibody-drug conjugates (ADCs) approved by US FDA: Mylotarg (2000, withdrawn in 2010), Adcetris (2011), Kadcyla (2013) and Besponsa (2017), while the second one Adcetris (the generic name is Brentuximab vedotin) is an auristatin-based ADCs. Adcetrisis formulated by the conjugation of brentuximab, an anti-CD30 (also known TNFRSF8) monoclonal antibody with payload monomethyl auristatinE (MMAE) via a cleavable peptide linker. CD30 is found on the surface of most classical Hodgkin lymphoma (HL) cells and in several types of non-Hodgkin lymphoma, but not commonly found on healthy cells. The auristatin-based ADC – Adcetris is approved in the United States 2011 for the treatment of Hodgkin lymphoma and one type of non-Hodgkin lymphoma: anaplastic large cell lymphoma (ALCL). More detailed description and international market of all these approved ADCs are elaborated in <strong><span style="color: #0000ff;"><a style="color: #0000ff;" href="https://www.creative-biolabs.com/adc/form/adc-clinical-trial-review.aspx">download resource</a></span></strong>.</span></p> <p><span style="font-size: 15px;">Antibody-drug conjugates (ADCs) have become a powerful class of therapeutics in oncology. With four approved drugs on the market and a total of 95 ADCs in clinical trials, ADCs represent a growing class as the next generation for cancer treatment. According to the subcellular function of payloads (toxic agent or drug), they can be categorized into 4 major classes: tubulin inhibitors, DNA toxins, topoisomerase I inhibitors, and undisclosed. With the success of Adcetris, tubulin inhibitors such as auristatins (MMAE, MMAF) are the one major class of payloads used in ADCs in clinical studies. According to the survey from scientists in Creative Biolabs, tubulin inhibitors contribute to more than 30% of the payloads in clinical ADCs, which accounts for the largest proportion in all payloads (Fig. 4). It is concluded that auristatin has great potential for application in ADC discovery and development.</span></p> <p> </p> ]]></content:encoded> </item> </channel> </rss>