The poster from the San Antonio Breast Cancer Symposium is now posted on CYDY's website. Click the top poster at this link.
https://www.cytodyn.com/publications
For those reading on a small screen, it may be difficult to maneuver on the poster. I am therefore including some of the main points below.
https://www.cytodyn.com/publications
For those reading on a small screen, it may be difficult to maneuver on the poster. I am therefore including some of the main points below.
Quote:Introduction
▪ Metastatic triple-negative breast cancer (mTNBC) is a particularly difficult-to-treat breast cancer subtype
with pretreated mTNBC having a very poor prognosis.
▪ In a US real-world study in patients with mTNBC who started first-line treatment, 51% of patients were subsequently treated with a second-line and 26% with a third-line treatment, while approximately 34% did not survive to receive next-line treatment after first- or second-line treatment.
▪ Among patients with locally recurrent, inoperable, or mTNBC treated with the immune checkpoint inhibitor (ICI) pembrolizumab plus chemotherapy, median overall survival (mOS) is greater for patients with a PD-L1 combined positive score (CPS) of ≥10, (23.0 months), compared to patients with a CPS score of <10, (14.7 months).
▪ In an analysis of 2,250 breast cancer patients, more than 95% of TNBC tumors were positive for C-C chemokine receptor 5 (CCR5).
▪ Leronlimab is a humanized monoclonal antibody that blocks CCR5 and reduces TNBC metastases by >98% in preclinical models.
Results
▪ Patients, median age was 48.5 years (range 32–83), patients received a median of 2 prior lines of metastatic therapy (range 0–5) (Table 1).
▪ Leronlimab was well tolerated with five grade 1 and two grade 2 treatment-related adverse events (TRAEs), plus expected chemo-related adverse events (AEs).
▪ No patients withdrew due to leronlimab TRAEs. No dose-limiting toxicities (DLTs) were observed up to the 700 mg QW SC dose.
▪ For all 28 patients, mOS after starting leronlimab treatment was 7.1 months (95% CI: 4.8–17.7 months) with survival at years 1, 2, 3, and 4 of 35.7%, 21.4%, 17.9% and 17.9%, respectively (Fig. 1).
▪ OS in subgroups of interest were assessed using univariable analyses without adjusting for differences in baseline characteristics. It is therefore possible that there were differences between subgroups.
▪ Compared to patients treated with the 350 mg QW SC dose of leronlimab, patients treated with either the 525 or 700 mg QW SC dose of leronlimab demonstrated significantly longer survival (HR 3.44, 95% CI: 1.2–9.9; P=0.0418) (Fig. 2).
▪ Compared to patients with an increase in CTCs/CAMLs after starting leronlimab, patients with a reduction in CTCs/CAMLs demonstrated longer survival (HR 7.11, 95% CI: 2.5–20.2; P=0.0007) (Fig. 3).
▪ Patients treated with leronlimab in combination with, or followed by, an ICI (N=7) demonstrated significantly longer survival compared to patients (N=21) who were not treated with leronlimab in combination with, or followed by an ICI (HR 4.14, 95% CI: 1.7–10.2; P=0.0041) (Fig. 4).
▪ As of 22 September 2025, all 5 patients treated with leronlimab in combination with, or followed by an ICI, and who significantly induced PD-L1 in their CTCs/CAMLs, were alive after a median of 60.9 months since initiating treatment with leronlimab.
▪ Two patients treated with leronlimab in combination with, or followed by an ICI, but who failed to significantly induced PD-L1 in their CTCs/CAMLs died (one at 5.0 months, and one at 5.6 months after starting leronlimab).
▪ Treatment with leronlimab (any dose) was associated with a significant upregulation of PD-L1 in circulating cells (i.e. CTCs and/or CAMLs) in 76% (n=16/21) of patients with post-baseline data (Fig. 5)
▪ Among the subset of patients who received leronlimab at a dose of 525 mg or 700 mg QW SC 88% (n=15/17) significantly upregulated PD-L1 in circulating cells.
Conclusions
▪ Leronlimab was well-tolerated with few TRAEs and no DLTs.
▪ Among all 28 patients, mOS was 7.1 months, with 5 patients (17.9%) still alive after a median of 60.9 months since starting treatment with leronlimab.
▪ Patients treated with either the 525 or 700 mg dose of leronlimab demonstrated significantly longer survival compared with patients treated with the 350 mg dose of leronlimab.
▪ Patients with a reduction in CTCs/CAMLs after starting leronlimab demonstrated significantly longer survival compared with patients with an increase in CTCs/CAMLs.
▪ Patients who were treated with leronlimab in combination with, or followed by, an ICI demonstrated prolonged survival. As of 22 September 2025, all 5 of the patients treated with leronlimab, in combination with, or followed by, an ICI, and who significantly induced PD-L1 in their CTCs/CAMLs were alive after a median of 60.9 months.
▪ Treatment with leronlimab was associated with a significant upregulation of PD-L1 in circulating cells (i.e. CTCs or CAMLs).
▪ Upregulation of PD-L1 with leronlimab treatment may “prime” the PD-L1 positivity in the tumor and its microenvironment. Thus, it may increase the proportion of patients eligible for treatment with an ICI and synergize with ICI efficacy. Further studies are warranted to confirm these findings.
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