Abstract P3-09-15: A phase 1b study of PVX-410 (PVX) vaccine plus durvalumab (DUR) as adjuvant therapy in HLA-A2+ early stage triple negative breast cancer (eTNBC) to assess safety and immune response

Author(s):  
Steven J Isakoff ◽  
Sylvia Adams ◽  
Hatem H Soliman ◽  
Nadine Tung ◽  
William T Barry ◽  
...  
2017 ◽  
Vol 35 (15_suppl) ◽  
pp. TPS1126-TPS1126 ◽  
Author(s):  
Steven J. Isakoff ◽  
Sara M. Tolaney ◽  
Nadine M. Tung ◽  
Sylvia Adams ◽  
Hatem Hussein Soliman ◽  
...  

TPS1126 Background: Stage 2-3 triple negative breast cancer (TNBC) remains at high risk for recurrence despite modern adjuvant therapy. An important role for the immune system in TNBC has recently emerged. Tumor infiltrating lymphocytes (TILs) are correlated with improved prognosis and several PD-1/PD-L1 checkpoint inhibitors, including Durvalumab (DUR), demonstrated activity in metastatic TNBC. Vaccines are a promising approach to further enhance the immune response in many cancers including TNBC. PVX-410 (PVX) is a novel tetra-peptide vaccine against XBP1 (2 splice variants), CD138 and CS1 that was safe and induced immune responses in a phase 1b study in smoldering myeloma. XBP1 and CD138 are also over-expressed in TNBC. Methods: This Phase 1b multi-center, single arm study will enroll 20 HLA-A2+ female patients (pts) following completion of all adjuvant therapy for stage 2-3 TNBC. Pts will receive 6 doses of 800ug PVX (emulsified in Montanide (SC) and co-administered with Hiltonol (IM)) at 2-week intervals, and 2 doses of DUR 1500mg IV at the 4th and 6th vaccine visits. Eligible pts must be between 1-6 months from completing adjuvant therapy, have no prior autoimmune disease, and have residual disease if neoadjuvant therapy was used. The primary objective is to determine the safety and tolerability of the combination, and the key secondary objective is to determine the immune response to PVX + DUR. If ≤1 pt in the first 6 has a protocol defined dose limiting toxicity within 4 weeks after the first DUR dose, accrual will continue to 20 pts. Immune response will be assessed at baseline, pre-dose 4 PVX/dose 1 DUR, and 4 weeks after completing protocol therapy. Paired data in 20 pts provides 90% power to see a shift of 0.75 standardized units from baseline to 4 weeks post treatment with the signed rank test. Immune response will be determined by a FACs based assay of antigen specific CD3+CD8+ T lymphocyte response and IFN-γ production (intracellular staining) in patient PBMCs. Additional correlative studies, including T-cell PD-1 and tissue PD-L1, XBP1, and CD138, are planned. Currently 4 pts are enrolled. Clinical trial information: NCT02826434.


2019 ◽  
Vol 37 (36) ◽  
pp. 3484-3492 ◽  
Author(s):  
Priyanka Sharma ◽  
William E. Barlow ◽  
Andrew K. Godwin ◽  
Eileen E. Parkes ◽  
Laura A. Knight ◽  
...  

PURPOSE To independently validate two biomarkers, a 44-gene DNA damage immune response (DDIR) signature and stromal tumor-infiltrating lymphocytes (sTILs), as prognostic markers in patients with triple-negative breast cancer (TNBC) treated with adjuvant doxorubicin (A) and cyclophosphamide (C) in SWOG 9313. METHODS Four hundred twenty-five centrally determined patient cases with TNBC from S9313 were identified. DDIR signature was performed on RNA isolated from formalin-fixed paraffin-embedded tumor tissue, and samples were classified as DDIR negative or positive using predefined cutoffs. Evaluation of sTILs was performed as described previously. Markers were tested for prognostic value for disease-free survival (DFS) and overall survival (OS) using Cox regression models adjusted for treatment assignment, nodal status, and tumor size. RESULTS Among 425 patients with TNBC, 33% were node positive. DDIR was tested successfully in 90% of patients (381 of 425), 62% of which were DDIR signature positive. DDIR signature positivity was associated with improved DFS (hazard ratio [HR], 0.67; 95% CI, 0.48 to 0.92; P = .015) and OS (HR, 0.61; 95% CI, 0.43 to 0.89; P = .010). sTILs density assessment was available in 99% of patients and was associated with improved DFS (HR, 0.70; 95% CI, 0.51 to 0.96; P = .026 for sTILs density ≥ 20% v < 20%) and OS (HR, 0.59; 95% CI, 0.41 to 0.85; P = .004 for sTILs density ≥ 20% v < 20%). DDIR signature score and sTILs density were moderately correlated ( r = 0.60), which precluded statistical significance for DFS in a joint model. Three-year DFS and OS in a subgroup of patients with DDIR positivity and T1c/T2N0 disease were 88% and 94%, respectively. CONCLUSION The prognostic role of sTILs and DDIR in early-stage TNBC was confirmed. DDIR signature conferred improved prognosis in two thirds of patients with TNBC treated with adjuvant AC. DDIR signature has the potential to stratify outcome and to identify patients with less projected benefit after AC chemotherapy.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A347-A347
Author(s):  
Shipra Gandhi ◽  
Mateusz Opyrchal ◽  
Cayla Ford ◽  
Victoria Fitzpatrick ◽  
Melissa Grimm ◽  
...  

BackgroundNeoadjuvant chemotherapy (NAC) with taxanes is the standard of care in triple negative breast cancer (TNBC). Intratumoral prevalence of CD8+ cytotoxic T-lymphocytes (CTLs) is associated with an improvement in relapse-free survival (RFS) and overall survival (OS), while regulatory T-cells (Treg) and myeloid derived suppressor cells (MDSC) are associated with poor survival. Higher ratio of CTL/Treg is associated with higher probability of obtaining pathological complete response (pCR), a surrogate marker for RFS. Intratumoral production of CCL5, CXCL9, CXCL10 and CXCL11 is critical for local infiltration with CTLs, while CCL22 is responsible for Treg attraction. Previous studies have shown that CXCL9 expression in the pre-treatment breast tissue is associated with a three-fold higher rate of achieving pCR. Our preclinical data show that Chemokine modulating (CKM) regimen, combining rintatolimod (TLR3 agonist), interferon (IFN)-α2b, and celecoxib (COX-2 inhibitor) increases CTL-attracting, and decreases MDSC-, Treg-favoring chemokines, increasing CTL/Treg ratio in tumor microenvironment, with preferential tumor tissue activation than adjacent healthy tissues. We hypothesize that the combination of CKM with paclitaxel will result in infiltration of TNBC with CTLs, and along with doxorubicin/cyclophosphamide (AC), result in higher pCR, translating into improved RFS and OS.MethodsIn this phase I study NCT04081389, eligibility includes age ≥18 years, confirmed resectable TNBC, radiographically measurable disease ≥1 cm, ECOG PS ≤ 2, adequate organ and marrow function. Patients with autoimmune disease, serious mood disorders, invasive carcinoma within 3 years, history of peptic ulcers or hypersensitivity to NSAIDs will be excluded. We plan to treat three patients with early stage TNBC with paclitaxel 80 mg/m2 IV weekly for 12 weeks, rintatolimod 200 mg IV, celecoxib 200 mg oral twice daily, and accelerated titration of IFN-α2b at doses 0, 5, or 10 million units (MU)/m2 [Dose Levels (DL) 1, 2 and 3 respectively] on days 1–3 (no intra-patient dose escalation) in weeks 1–3. Dose-limiting toxicity (DLT) is defined as grade 3 or higher toxicities within the first 3 weeks. Any DLT will mandate recruitment per the 3+3 model. If no DLT, three patients will be enrolled at DL 4 at 20 MU/m2 IFN- α2b. This will be followed by standard dose-dense AC, and then surgery. The primary endpoint is safety and tolerability of combination and to identify the appropriate DL of CKM and paclitaxel for extended efficacy study. The secondary endpoints include investigation of efficacy (pCR and breast MRI response), along with RFS and OS. Intratumoral biomarkers will be analyzed in an exploratory manner.ResultsN/AConclusionsN/ATrial RegistrationNCT04081389Ethics ApprovalThe study was approved by Roswell Park Comprehensive Cancer Center Institution’s Ethics Board, approval number I-73718.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A644-A644
Author(s):  
Anita Mehta ◽  
Madeline Townsend ◽  
Madisson Oliwa ◽  
Patrice Lee ◽  
Nicholas Saccomano ◽  
...  

BackgroundPoly(ADP-ribose) polymerase inhibitors (PARPi) have improved the outcomes of BRCA-associated breast cancer; however, treatment responses are often not durable. Our preclinical studies demonstrated that PARPi activates the cGAS/STING pathway and recruitment of anti-tumor CD8+ T-cells that are required for tumor clearance [1]. These studies contributed to development of clinical trials testing PARPi plus immune checkpoint blockade (ICB). Unfortunately, early phase trials of PARPi + ICB have not yet suggested efficacy will be superior to PARPi monotherapy. Lack of demonstrated clinical synergy between PARPi + ICB underscores the need to study the tumor microenvironment (TME) during PARPi therapy to identify optimal strategies to enhance T-cell activation. We recently showed that PARPi induces CSF-1R+ suppressive tumor associated macrophages (TAMs) that restrict antitumor immune responses, contributing to PARPi resistance [2]. Removing TAMs with anti-CSF-1R therapy in combination with PARPi significantly enhanced overall survival (OS) compared to PARPi monotherapy in preclinical models [2]. Here, we investigate how modulating TAMs can enhance PARPi + ICB.MethodsMice bearing BRCA1-deficient TNBC (K14-Cre;Brca1f/f;p53f/f) tumors were treated for 98 days with PARPi (Talazoparib) ± small molecule inhibitor of CSF-1R (ARRAY-382; CSF-1Ri) ± anti-PD-1 and then followed for survival. Flow cytometry was employed to elucidate changes in the TME after treatment.ResultsPARPi conferred a significant survival advantage over vehicle treated mice (median OS 33 v. 14 days; p=0.0034) and 2/8 PARPi-treated mice experienced complete tumor clearance at day 98. PARPi + CSF-1Ri treated mice (median OS 140 days) remarkably cleared 7/10 tumors by day 98. The addition of anti-PD-1 to PARPi did not enhance OS compared to PARPi monotherapy. The triple combination of anti-PD-1 + PARPi + CSF-1Ri has not yet significantly enhanced the median OS compared to PARPi + CSF-1Ri (ongoing; 168 v. 140 days); nor did it increase clearance of tumor by day 98 (7/10). However, the triple combination led to superior long term tumor clearance. At day 161 the triple combination exhibited 5/10 tumor free mice compared to 2/10 treated with PARPi + CSF-1Ri. To elucidate how CSR-1Ri enhanced PARPi + ICB responses, flow cytometry was performed and revealed increased expression of the co-stimulatory molecule CD80, reduced tissue resident macrophages (CX3CR1+) and lower CSF-1R expression compared to PARPi + ICB.ConclusionsThese data suggest that targeting immunosuppressive macrophages may induce a favorable anti-tumor immune response and enhance responses to PARPi plus ICB. We are currently evaluating the adaptive immune response in this context.ReferencesPantelidou, C., et al., PARP inhibitor efficacy depends on CD8+ T cell recruitment via intratumoral STING pathway activation in BRCA-deficient models of triple-negative breast cancer. Cancer Discovery, 2019: p. CD-18-1218.Mehta, A.K., et al., Targeting immunosuppressive macrophages overcomes PARP inhibitor resistance in BRCA1-associated triple-negative breast cancer. Nat Cancer, 2021. 2(1): p. 66–82.


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