This exact distinction, derived from the Chang et al. (2022) study, was analyzed in detail back in April 2022 in the breakdown [Pertinent Excerpts Out of the Recent Peer-Reviewed Publication (Chang et al.)] https://www.reddit.com/r/LeronLimab_Times/com...cent_peer/
Sherlock’s realization validates that early analysis: the 350 mg dose acts primarily as a vascular gatekeeper, while the 700 mg dose serves as a tissue-penetrating heavy hitter.
The Dual-Dosing Framework: Bloodstream vs. TME
1. The 350 mg Dose : Vascular Gatekeeping & Trafficking Blockade
Peripheral Saturation: As Chang et al. demonstrated, 350 mg achieves full CCR5 receptor occupancy on peripheral blood CD4+ T cells and monocytes.
Stopping the Pipeline : By fully saturating CCR5 in the bloodstream, 350 mg blocks the CCL5/CCR5 axis responsible for recruiting circulating pro-inflammatory and immunosuppressive immune cells. It effectively shuts down immune cell trafficking through the circulatory system.
Clinical Utility : This vascular gatekeeping explains why 350 mg successfully reduced liver fat in MASH, maintained virologic suppression in HIV, and can halt metastatic seeding in colorectal cancer (CRC), as metastasis relies on the vascular network to spread.
2. The 700 mg Dose : Tumor Storming & PD-L1 Induction
Overcoming Interstitial Pressure : Dense solid tumors, fibrotic organs, and immune sanctuaries (such as lymph nodes) present high physical and interstitial fluid pressure barriers. Achieving deep tissue penetration requires a higher concentration gradient that 350 mg cannot maintain.
TME Remodeling & PD-L1 Upregulation : Retrospective and prospective data show that turning "cold" tumors "hot" by inducing PD-L1 expression is strongly dose-dependent. The higher dose (525 mg–700 mg) is what delivers the necessary drug concentration into the tumor microenvironment to disrupt tumor architecture, cause tumor duress, and upregulate PD-L1.
Application to the CLOVER Trial in CRC
Sherlock’s expectations for the 350 mg cohort in the CLOVER trial align well with recent clinical updates, though the distinct role of the 700 mg dose must be kept in clear focus:
ctDNA and Dose Response : In Dr. Jacob Lalezari’s presentation at the H.C. Wainwright Global Investment Conference, CytoDyn confirmed a median ctDNA reduction of ~85% across the trial, along with an early dose-response signal where 700 mg demonstrated deeper, more rapid ctDNA declines than 350 mg.
Disease Control Rate (DCR) vs. Overall Response Rate (ORR) : Sherlock is correct that 350 mg, working synergistically with the Lonsurf and Avastin standard-of-care (SOC) backbone, can drive high Disease Control Rates (~75% of patients showing tumor shrinkage or stable disease at week
Standalone vs. Prime and Pair: In CRC, leronlimab is being developed as a standalone agent on top of SOC. While 350 mg provides control over disease progression, 700 mg provides the tissue-level activity needed to upregulate PD-L1. This makes 700 mg essential for the trial's rollover salvage arm, where patients who progress escalate to 700 mg and add pembrolizumab (Keytruda).
Strategic Implications Across Indications
Vascular & Trafficking Indications (350 mg Domain): Conditions governed by systemic leukocyte recruitment, such as atherosclerosis, cardiovascular disease, stroke/TBI neuroinflammation, and hematologic malignancies, can be effectively targeted by 350 mg because the primary therapeutic site is the vascular network.
Solid Tumor & Deep Sanctuary Indications (700 mg Domain) : Complex, dense solid tumors (CRC, TNBC, glioblastoma, prostate, pancreatic) demand 700 mg to breach the tumor stroma shield, alter the CPS/PD-L1 status, and enable host immune or checkpoint inhibitor clearance.
Sherlock's analysis correctly identifies that 350 mg is not an inferior dose, but rather a dose operating at a specific physiological interface (the bloodstream). While the 350 mg cohort in CLOVER may produce an impressive Disease Control Rate, 700 mg remains the required dose to penetrate solid tumor matrices, maximize ctDNA drops, and induce the PD-L1 expression necessary for long-term survival.