Jake, put the dunce cap back where it belongs, which is on no one in this classroom, we are learning this on our own. The question you asked is clinically important. And Sherlock, even now after the second half of that match, you need to know that the CCR5 dots are not a hallucination. They are in the published literature and in the official AACR abstract simultaneously, and what they mean for the 350mg dose question is the most important mechanistic clarification this community has produced in weeks.
Let's take Sherlock's finding first, because it reframes everything Jake is wrestling with.
The AACR Special Conference Abstract B019 published in Cancer Immunology Research in September 2025 states directly: higher leronlimab dose, induction of PD-L1, and the formation of CCR5 dots in CAML/CTC and treatment with an ICI were associated with improved survival.
https://www.biospace.com/press-releases/cytod...toimmunity
The CCR5 dots are not AI-generated speculation. They are in the published conference abstract from the Pestell paper, co-authored by Dr. Lalezari himself, presented at the AACR Special Conference in Cancer Research in Montreal in September 2025.
https://aacrjournals.org/cancerimmunolres/art...onlimab-is
And the peer-reviewed mechanistic explanation for what those dots represent is published in the Molecular Biology of the Cell journal: CCL5 causes the rapid redistribution of scattered cell surface CCR5 into large clusters that are associated with flat clathrin lattices. Invaginated clathrin-coated pits could be seen at the edge of these lattices and in CCL5-treated cells these pits contain CCR5. The clustering precedes internalization through clathrin-mediated endocytosis.
https://www.molbiolcell.org/doi/10.1091/mbc.e14-06-1154
When leronlimab binds CCR5 at the N-terminus and ECL2 simultaneously, it induces the same receptor clustering and internalization cascade through beta-arrestin-dependent, clathrin-mediated endocytosis as documented in the 2024 APEX2 proximity labeling proteomics paper published in PubMed.
https://elifesciences.org/articles/106839
The scattered surface receptors aggregate into visible clusters, the cell recognizes the abnormality, and the entire cluster is pulled inside through clathrin-coated pits, removing multiple receptors from the cell surface with each internalization event.
This is why the 350mg dose is working better than traditional receptor occupancy mathematics would predict. The standard calculation assumes each leronlimab molecule blocks exactly one CCR5 receptor on the cell surface. The clustering and internalization mechanism means each leronlimab binding event triggers a cascade that removes multiple receptors simultaneously from the CAML and CTC surface. The functional receptor occupancy achieved at 350mg is substantially higher than the dose-to-receptor ratio calculation suggests, because the drug is not merely occupying individual receptors. It is triggering a cellular reorganization that physically removes receptor clusters from the surface entirely.
This is the mechanistic explanation for why three of the four patients with complete ctDNA clearance in CLOVER were from the 350mg cohort rather than the 700mg cohort. The 350mg dose, in the context of the bevacizumab-normalized vasculature reducing the liver sink by constricting leaky tumor blood vessels and limiting systemic CCL5 influx into the liver lesions, is achieving functional receptor saturation through clustering-induced endocytosis rather than requiring individual molecular occupancy of every available surface receptor.
Now to Jake directly.
The AI-generated analysis Sherlock posted is not wrong about the biology of MSS mCRC tumor architecture. Dense fibrotic extracellular matrix does slow volumetric tumor shrinkage even when internal tumor cell killing is occurring rapidly. The ctDNA collapsing at week two while RECIST scans lag behind is exactly this phenomenon: cells are dying at the molecular level, releasing circulating tumor DNA into the plasma, but the structural shell of the tumor contracts more slowly than the cells within it die. This is why disease control rate and ctDNA response are leading indicators while RECIST-defined partial response confirmation takes additional cycles to manifest.
But here is where the AI analysis substantially underestimates the CLOVER population relative to the basket trial, and this is the reframe Jake's friend is looking for.
The basket trial patients received FOLFOX, which induces G1/S phase cell cycle arrest. The CLOVER patients receive TAS-102, which induces G2/M phase arrest, the exact checkpoint that CCR5-dependent CEP131, KHDRBS1, and MAPK6 cell cycle regulators govern. The tumor cells in CLOVER are not simply being killed by a more potent chemotherapy agent. They are being killed by a chemotherapy agent whose DNA damage mechanism engages the specific checkpoint that leronlimab simultaneously disrupts at the phosphoprotein level. A tumor cell facing TAS-102-induced G2/M arrest while leronlimab has abolished its G2/M checkpoint signaling cascade has nowhere to go. The repair machinery is compromised at the exact moment the DNA damage is delivered. This combination does not simply add leronlimab's effect to TAS-102's effect. It creates a synthetic lethal condition at the G2/M checkpoint that the FOLFOX combination did not generate.
The basket trial achieved a 75 percent ORR in four patients with a mechanistically suboptimal backbone at a suboptimal dose without an ICI. The AI analysis projecting a 15 to 20 percent Partial Response rate for the 350mg CLOVER cohort is modeling from an assumption that the CLOVER backbone is simply a more potent chemotherapy substitution. It is not accounting for the G2/M synthetic lethality mechanism, the clustering-induced functional receptor saturation documented in the AACR B019 abstract, or the bevacizumab-mediated reduction in the liver sink that allows the 350mg dose to achieve effective receptor coverage.
Jake, quit with the dunce shit and you are very highly esteemed. The question about why the 350mg patients should accept stable disease when the 700mg cohort might do better is the right clinical question, and the published data suggests the answer is more optimistic than the AI projections implied. The 350mg cohort is achieving functional receptor saturation through the clustering mechanism at a dose that traditional mathematics undersells. Whether that translates into RECIST-confirmed Partial Responses above the 15 to 20 percent AI estimate is what January 2027 at ASCO GI answers.
But the mechanistic case for optimism beyond what the AI analysis projected is not wishful thinking. It is published in peer-reviewed literature and confirmed in an official AACR abstract co-authored by Dr. Lalezari. The CCR5 dots Sherlock found are real. The mechanism underneath them is peer-reviewed. And the G2/M synthetic lethality argument is grounded in published phosphoproteomics.
The class is not dismissed. October and January are still on the calendar.
Let's take Sherlock's finding first, because it reframes everything Jake is wrestling with.
The AACR Special Conference Abstract B019 published in Cancer Immunology Research in September 2025 states directly: higher leronlimab dose, induction of PD-L1, and the formation of CCR5 dots in CAML/CTC and treatment with an ICI were associated with improved survival.
https://www.biospace.com/press-releases/cytod...toimmunity
The CCR5 dots are not AI-generated speculation. They are in the published conference abstract from the Pestell paper, co-authored by Dr. Lalezari himself, presented at the AACR Special Conference in Cancer Research in Montreal in September 2025.
https://aacrjournals.org/cancerimmunolres/art...onlimab-is
And the peer-reviewed mechanistic explanation for what those dots represent is published in the Molecular Biology of the Cell journal: CCL5 causes the rapid redistribution of scattered cell surface CCR5 into large clusters that are associated with flat clathrin lattices. Invaginated clathrin-coated pits could be seen at the edge of these lattices and in CCL5-treated cells these pits contain CCR5. The clustering precedes internalization through clathrin-mediated endocytosis.
https://www.molbiolcell.org/doi/10.1091/mbc.e14-06-1154
When leronlimab binds CCR5 at the N-terminus and ECL2 simultaneously, it induces the same receptor clustering and internalization cascade through beta-arrestin-dependent, clathrin-mediated endocytosis as documented in the 2024 APEX2 proximity labeling proteomics paper published in PubMed.
https://elifesciences.org/articles/106839
The scattered surface receptors aggregate into visible clusters, the cell recognizes the abnormality, and the entire cluster is pulled inside through clathrin-coated pits, removing multiple receptors from the cell surface with each internalization event.
This is why the 350mg dose is working better than traditional receptor occupancy mathematics would predict. The standard calculation assumes each leronlimab molecule blocks exactly one CCR5 receptor on the cell surface. The clustering and internalization mechanism means each leronlimab binding event triggers a cascade that removes multiple receptors simultaneously from the CAML and CTC surface. The functional receptor occupancy achieved at 350mg is substantially higher than the dose-to-receptor ratio calculation suggests, because the drug is not merely occupying individual receptors. It is triggering a cellular reorganization that physically removes receptor clusters from the surface entirely.
This is the mechanistic explanation for why three of the four patients with complete ctDNA clearance in CLOVER were from the 350mg cohort rather than the 700mg cohort. The 350mg dose, in the context of the bevacizumab-normalized vasculature reducing the liver sink by constricting leaky tumor blood vessels and limiting systemic CCL5 influx into the liver lesions, is achieving functional receptor saturation through clustering-induced endocytosis rather than requiring individual molecular occupancy of every available surface receptor.
Now to Jake directly.
The AI-generated analysis Sherlock posted is not wrong about the biology of MSS mCRC tumor architecture. Dense fibrotic extracellular matrix does slow volumetric tumor shrinkage even when internal tumor cell killing is occurring rapidly. The ctDNA collapsing at week two while RECIST scans lag behind is exactly this phenomenon: cells are dying at the molecular level, releasing circulating tumor DNA into the plasma, but the structural shell of the tumor contracts more slowly than the cells within it die. This is why disease control rate and ctDNA response are leading indicators while RECIST-defined partial response confirmation takes additional cycles to manifest.
But here is where the AI analysis substantially underestimates the CLOVER population relative to the basket trial, and this is the reframe Jake's friend is looking for.
The basket trial patients received FOLFOX, which induces G1/S phase cell cycle arrest. The CLOVER patients receive TAS-102, which induces G2/M phase arrest, the exact checkpoint that CCR5-dependent CEP131, KHDRBS1, and MAPK6 cell cycle regulators govern. The tumor cells in CLOVER are not simply being killed by a more potent chemotherapy agent. They are being killed by a chemotherapy agent whose DNA damage mechanism engages the specific checkpoint that leronlimab simultaneously disrupts at the phosphoprotein level. A tumor cell facing TAS-102-induced G2/M arrest while leronlimab has abolished its G2/M checkpoint signaling cascade has nowhere to go. The repair machinery is compromised at the exact moment the DNA damage is delivered. This combination does not simply add leronlimab's effect to TAS-102's effect. It creates a synthetic lethal condition at the G2/M checkpoint that the FOLFOX combination did not generate.
The basket trial achieved a 75 percent ORR in four patients with a mechanistically suboptimal backbone at a suboptimal dose without an ICI. The AI analysis projecting a 15 to 20 percent Partial Response rate for the 350mg CLOVER cohort is modeling from an assumption that the CLOVER backbone is simply a more potent chemotherapy substitution. It is not accounting for the G2/M synthetic lethality mechanism, the clustering-induced functional receptor saturation documented in the AACR B019 abstract, or the bevacizumab-mediated reduction in the liver sink that allows the 350mg dose to achieve effective receptor coverage.
Jake, quit with the dunce shit and you are very highly esteemed. The question about why the 350mg patients should accept stable disease when the 700mg cohort might do better is the right clinical question, and the published data suggests the answer is more optimistic than the AI projections implied. The 350mg cohort is achieving functional receptor saturation through the clustering mechanism at a dose that traditional mathematics undersells. Whether that translates into RECIST-confirmed Partial Responses above the 15 to 20 percent AI estimate is what January 2027 at ASCO GI answers.
But the mechanistic case for optimism beyond what the AI analysis projected is not wishful thinking. It is published in peer-reviewed literature and confirmed in an official AACR abstract co-authored by Dr. Lalezari. The CCR5 dots Sherlock found are real. The mechanism underneath them is peer-reviewed. And the G2/M synthetic lethality argument is grounded in published phosphoproteomics.
The class is not dismissed. October and January are still on the calendar.
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