Doxorubicin In Patients Research Articles

Lenvatinib Plus Pembrolizumab versus Doxorubicin for Advanced or Recurrent Endometrial Cancer with Short Treatment-Free Intervals Following First-Line Carboplatin Plus Paclitaxel

Background: The treatment-free interval is a significant predictor of worse prognosis and poor response rates of the second-line treatment in patients with carboplatin and paclitaxel (PT)-pretreated, advanced, or recurrent endometrial cancer (EC). Whether lenvatinib plus pembrolizumab still confers a survival benefit compared with doxorubicin in patients with platinum-free intervals of <6 months remains unclear. Methods: This multi-institutional retrospective analysis was performed using de-identified electronic health records from the TriNetX Research Network. Patients with advanced or recurrent ECs who received lenvatinib plus pembrolizumab or doxorubicin within six months of first-line PT were identified. A 1:1 propensity score matching (PSM) was conducted to control for potential confounding variables. Overall survival (OS) and adverse event profile were the primary and secondary outcomes. Results: Between January 2018 and February 2024, 130 patients with PT-treated, advanced, or recurrent ECs who received lenvatinib plus pembrolizumab and 122 patients who received doxorubicin at a platinum-free interval of <6 months were identified across 31 healthcare organizations. In the balanced cohort following PSM with 117 patients in each group, treatment with lenvatinib plus pembrolizumab was associated with improved OS compared with treatment with doxorubicin (12.8 vs. 8.2 months, p = 0.012, hazard ratio: 0.65, 95% confidence interval: 0.46–0.91). Regarding adverse event analysis, a higher incidence of hypothyroidism and proteinuria was observed with lenvatinib plus pembrolizumab, and more hematological toxicities were observed with doxorubicin. Conclusions: in patients with treatment-free intervals of <6 months, lenvatinib plus pembrolizumab still confers improved survival compared with doxorubicin in PT-treated, advanced, or recurrent ECs.

Evaluation of oral silymarin formulation efficacy in prevention of doxorubicin induced hepatotoxicity in patients with non-metastatic breast cancer.

Chemotherapy-induced hepatotoxicity is a common complication in breast cancer patients, especially with doxorubicin-containing regimens. Liver enzyme abnormality is reported in 34.8% of patients undergoing AC-T regimen and fatty liver is reported in 30% to 50% of cases. Antioxidant and anti-inflammatory properties of silymarin, a polyphenolic flavonoid extract derived from Silybum marianum, may be useful in preventing chemotherapy-induced hepatotoxicity. This study evaluated the effect of oral silymarin for preventing doxorubicin induced hepatotoxicity in non-metastatic breast cancer patients. In this triple-blind, placebo-controlled clinical trial, 50 patients with non-metastatic breast cancer were assigned to receive either 140 mg silymarin tablets or the placebo three times daily for 63 days and were evaluated for liver function test before the study and at the end of each chemotherapy cycle (every 3 weeks) for 4 cycles. In addition, an ultrasonography assessment was performed upon entry and the end of the study. Based on ultrasonography, the fatty liver grade was significantly higher in the placebo group at the end of the study. Moreover, the serum levels of aspartate aminotransferase (p = 0.015) and alkaline phosphatase (p = 0.004) at 6-week intervals, and the serum level of alkaline phosphatase (p = 0.002) at 9-week intervals were significantly lower in the silymarin group. Oral formulation of silymarin 420 mg/day for 63 days significantly prevented hepatotoxicity caused by doxorubicin in patients with non-metastatic breast cancer mostly based on liver ultrasonography but not laboratory parameters. Further investigations are suggested on different doses, durations and formulations of silymarin, particularly nano-formulations for increasing its oral bioavailability.

Molecular-genetic predictors of cardiotoxicity 12 months after the end of chemotherapy with doxorubicin in patients with breast cancer

Molecular-genetic predictors of cardiotoxicity 12 months after the end of chemotherapy with doxorubicin in patients with breast cancer

Changes in left ventricular systolic and diastolic function after chemotherapy for breast cancer with doxorubicin

Introduction. Detection of the cardiotoxic effect during chemotherapy (CT) for malignant neoplasms is one of the most important tasks of a practicing physician. Purpose: to study changes in left ventricular systolic and diastolic function using echocardiography (EchoCG) during chemotherapy with doxorubicin in patients with primary breast cancer (BC) and to identify potential markers of early cardiotoxicity (CT).Material and Methods. The study included 100 patients with a confirmed diagnosis of breast cancer who were treated at the health care institution “Grodno University Clinic” (Grodno, Belarus).Results. In the study sample, a number of EchoCG parameters were measured before and after chemotherapy in 100 patients with breast cancer. Depending on the choice of the threshold level of relative reduction in global longitudinal strain (GLS) in %, different median values were recorded in the subgroups with and without CT (before and after chemotherapy). Data are presented on the difference in the relative dynamics of EchoCG indicators in % between the subgroups with CT and without CT, which shows how large the differences between the subgroups are in % after the end of chemotherapy. Against the background of the absence of statistically significant differences, trends towards an increase or decrease in indicators were recorded, which can characterize them as potential CT markers.Conclusion. We hypothesize that indexed end-systolic volume, indexed end-diastolic volume, early diastolic peak velocity of lateral mitral annulus motion may be considered as potential CT markers in the subclinical stage along with GLS; if it is impossible to measure a relative decrease in GLS, these indicators collectively may indicate the development of a CT effect at the subclinical stage. When diagnosing a relative decrease in the GLS index by less than 15 %, but by more than 10 %, we propose to consider the indexed end-systolic volume index as a marker of the early CT effect if its increase after the end of chemotherapy is recorded by 10 % or more, respectively.

Induced pluripotent stem cell-derived cardiac myocytes to assess anthracycline cardiotoxicity

Abstract Background Current oncological treatments improved survival but also increased awareness of cardiovascular side-effects following cancer therapy. Anthracyclines are a class of highly effective chemotherapeutics, yet their use is regularly complicated by anthracycline-induced cardiotoxicity (AIC). The advent of induced pluripotent stem cell-derived cardiac myocytes (iPSC-CMs) offers the potential for disease modeling and prediction of genetic cardiomyopathies. Purpose We aim to use iPSC-CMs to assess susceptibility to cardiotoxicity induced by anti-cancer treatments on an individual patient level. Furthermore, the assay could be exploited to unravel cellular processes and pathways involved in AIC. Methods Five heart transplant patients following AIC and five anthracycline treated patients without AIC were included in our study. We reprogrammed patient-derived lymphocytes from both groups toward iPSCs using Sendai Virus; afterwards, patient derived iPSCs were differentiated into CM-like cells. Cytotoxicity following chemotherapy exposure was assessed using flow cytometry (FC), in which iPSC-CM-specific cells were first selected based on the expression of signal-regulatory protein alpha (SIRPA) surface marker; thereafter the percentage of apoptotic versus viable cells following doxorubicin exposure was quantitatively assessed. Ultrastructural changes were evaluated using electron microscopy (EM) images, comparing doxorubicin treated and untreated iPSC-CMs. Reactive Oxygen Species (ROS) generation following doxorubicin exposure was assessed using a luciferin precursor-based plate reader assay (ROS-GLO) and FC. Furthermore, whole genome sequencing (WGS) was performed and variants were filtered based on allele frequency, pathogenicity using HumVar trained variant effect predictors and presence in patients versus controls. Results The cytotoxic effect of increasing concentrations of doxorubicin was quantifiable using FC on SIRPA positive iPSC-CMs (Figure 1 panel A). On the ultrastructural level, doxorubicin treated iPSC-CMs manifested darker and more condensed mitochondria as seen with EM (Figure 1 panel B). Increased ROS production was observed following doxorubicin exposure as assessed using ROS-GLO plate reader assay and FC (Figure 1 panel C). We used iPSC-CMs of transplant patients and matched controls to assess inter-individual susceptibility to anthracycline-induced cardiotoxicity. Included patient profiles can be found in Figure 2 panel A. There was a higher rate of cell death at any concentration of doxorubicin in patients with proven AIC as opposed to controls (Figure 2 panel B). WGS analysis showed 2 pathogenic variants in the PRAMEF6 gene present in cases and not in controls (Figure 3 panel C). Conclusion iPSC-CMs represent a robust disease model to study cancer therapy-induced cardiotoxicity. Furthermore, iPSC-CMs allow to study inter-individual differences in susceptibility to cancer therapy-induced cardiotoxicity.Mechanism of AICSusceptibility to AIC

Allelic variant 6A (rs35068180) of the MMP-3 promoter region as a predictor of cardiotoxicity after the end of adjuvant chemotherapy with doxorubicin in patients with breast cancer

Aim. To evaluate the relationship of polymorphic variants rs2232228 of the HAS3 gene, rs8187710 of the ABCC2 gene, rs35068180 of the MMP-3 gene with cardiotoxicity after the end of adjuvant chemotherapy in patients with breast cancer.Material and methods. The study included 100 patients (women, mean age 52,5±9,4 years) diagnosed with breast cancer who received anthracycline antibiotics (doxorubicin, total dose 240 mg/m2 or 360 mg/m2). Echocardiography was performed before and after the end of chemotherapy. Polymorphic status of selected targets was determined using the real-time polymerase chain reaction.Results. After the end of chemotherapy, based on the changes of left ventricular ejection fraction and global longitudinal strain, cardiotoxicity (CT) was detected in 20 patients. There were following significant differences between subgroups: rs8187710 of the ABCC2 gene — not identified; rs2232228 of the HAS3 gene — genotype AA, odds ratio (OR) 3,37 (95% confidence interval (CI) 1,14; 9,97) and allelic variant A, OR 2,17 (95% CI 0,98; 4,80) are significantly more common (p<0,05) in the cardiotoxicity+ subgroup; rs35068180 of the MMP-3 gene — genotype 6A/6A, OR 2,53 (95% CI 0,93; 6,88) and allelic variant 6A, OR 2,19 (95% CI 1,08; 4,44) are significantly more often (p<0,05) in the cardiotoxicity+ subgroup.Conclusion. Genotype 6A/6A, allelic variant 6A rs35068180 of the MMP-3 gene, genotype AA and allelic variant A rs2232228 of the HAS3 gene can be considered as predictors of early cardiotoxicity after the end of chemotherapy in patients with breast cancer receiving doxorubicin.

The Effect of Aerobic Training and Nanomicelle Curcumin Supplementation on MDA and BAX And BCL2 Activity Levels on Cardiotoxicity of Mice Infected with Breast Cancer in the Phase of Mani with Doxorubicin

Background: Doxorubicin is a universal drug in the treatment of all types of cancers, which is limited due to its many side effects. Therefore, the present study has investigated the effect of aerobic exercise and the use of curcumin nano micelles on the activity levels of BAX, BCL2, and MDA concentration in doxorubicin-induced cardiotoxicity in mice with breast cancer.
 Methods: In this research, which was of a fundamental type and controlled experimentally, 24BalbC female rats were randomly divided into 4 groups: doxorubicin, doxorubicin patient and exercise, doxorubicin patient and nano curcumin supplement and doxorubicin patient, exercise and supplement. Breast cancer induction was done with MC4-L2 cells. Doxorubicin 2mg/kg was injected subcutaneously 6 times on day 28, 21, 14, 7, 1 and 35. The aerobic program consisted of 5 sessions per week for 42 days with an increase in the speed of the treadmill every two weeks including 14, 16, and 18 meters per minute and the use of nano curcumin at a dose of 100mg/k. The collected data were analyzed with a two-way analysis of variance with a significance level of 0.05 in the tests.
 Results: 6 weeks of aerobic training had no effect on BCL2 activity and MDA concentration, but it significantly decreased BAX activity. Taking nano curcumin supplement for 6 weeks decreased BAX activity and MDA concentration and significantly increased BCL2 activity. Conclusion 6 A week of aerobic training along with nano curcumin supplementation did not affect BAX activity and MDA concentration, but it caused an increase in BCL2 activity (p value < 0.05).
 Conclusion: Aerobic exercise and the use of curcumin nano micelle supplement separately or at the same time can be effective in reducing the cardiac toxicity of doxorubicin in patients with breast cancer.

LBA90 A randomized phase II study of durvalumab and tremelimumab compared to doxorubicin in patients with advanced or metastatic soft tissue sarcoma (MEDISARC, AIO-STS-0415)

LBA90 A randomized phase II study of durvalumab and tremelimumab compared to doxorubicin in patients with advanced or metastatic soft tissue sarcoma (MEDISARC, AIO-STS-0415)

Abstract P2175: Induced Pluripotent Stem Cell-derived Cardiac Myocytes To Assess Anthracycline Cardiotoxicity

Background: Anthracyclines are a class of highly effective chemotherapeutics, yet their use is regularly complicated by anthracycline-induced cardiotoxicity (AIC). The advent of induced pluripotent stem cell-derived cardiac myocytes (iPSC-CMs) offers the potential for disease modeling and prediction of genetic cardiomyopathies. Purpose: We aim to use iPSC-CMs to assess susceptibility to AIC. Methods: Five AIC heart transplant patients and five anthracycline treated patients without AIC were included in our study. We reprogrammed lymphocytes from both groups toward iPSCs using Sendai Virus, followed by differentiation into CM-like cells. Cytotoxicity following chemotherapy exposure was assessed using flow cytometry (FC), electron microscopy (EM) and reactive oxygen species generation (ROS). Furthermore, whole genome sequencing (WGS) was performed and variants were filtered based on allele frequency, pathogenicity using HumVar trained variant effect predictors and presence in patients versus controls. Results: The cytotoxic effect of increasing concentrations of doxorubicin was quantifiable using FC on SIRPA positive iPSC-CMs ( A ). There was a higher rate of cell death at any concentration of doxorubicin in patients with AIC as opposed to controls ( B ). On the ultrastructural level, doxorubicin treated iPSC-CMs manifested darker and more condensed mitochondria as seen with EM ( C ). Increased ROS production was observed following doxorubicin exposure ( D ). WGS analysis showed 2 pathogenic variants in the PRAMEF6 gene present in cases and not in controls ( E ). Conclusion: iPSC-CMs represent a robust disease model to study mechanisms of and susceptibility to AIC.

Safety and clinical activity of TTI-621 in combination with doxorubicin in patients with unresectable or metastatic high-grade leiomyosarcoma: Results from the low-dose expansion cohort.

11508 Background: TTI-621 is a recombinant fusion protein combining the Fc region of human IgG1 with a fragment of human SIRPα, designed as a decoy receptor for CD47 on tumor cells to interrupt CD47-SIRPα signaling and promote macrophage-mediated phagocytosis of tumor cells as well as activation of NK cells. Preclinical studies suggest TTI-621 may enhance the response to doxorubicin in macrophage-rich tumors that express CD47, such as leiomyosarcoma (LMS). A phase 1/2 dose escalation study with high- and low-dose expansion cohorts evaluating TTI-621 + doxorubicin in patients (pts) with advanced LMS is ongoing (NCT04996004); results from the low-dose expansion cohort are presented. Methods: This open-label study enrolled anthracycline-naïve pts aged ≥18 y with evaluable unresectable or metastatic high-grade LMS and ≤1 prior line of therapy for advanced disease. Pts in the low-dose expansion cohort received TTI-621 0.2 mg/kg on Days 1 and 8 in combination with doxorubicin 75 mg/m2 on Day 1 of 21-day cycles for a maximum 6 cycles, followed by TTI-621 monotherapy on Days 1 and 15 of 28-day cycles until objective disease progression. Primary objectives for the expansion phase were evaluation of safety and investigation of clinical activity via assessment of overall response and clinical benefit rates as defined by RECIST v1.1 criteria. Results: At data cut-off (Oct 3, 2022), 23 pts were evaluable for safety and 20 for clinical response. In the safety population, 39% had received prior treatment for advanced disease. Two pts (9%) experienced Grade ≥3 AE assessed as related to TTI-621 treatment: pancreatitis (n = 1, 4%) and platelet count decreased (n = 1, 4%). Seven pts (30%) experienced Grade ≥3 AE related to the combination of TTI-621 and doxorubicin, including two pts (9%) each with platelet count decreased and white blood cell count decreased and three pts (13%) with neutrophil count decreased. Grade ≥3 doxorubicin-related AEs were more common (n = 17, 74%); most frequent were neutrophil count decreased (n = 8; 35%), white blood cell count decreased (n = 7; 30%), and neutropenia (n = 6; 26%). One pt experienced an infusion-related reaction (Grade 1 chills) assessed as related to TTI-621. No pts attained complete response, but one pt had a complete resolution of all target lesions. Five pts (25%) attained partial response for an overall response rate of 25%; 11 pts (55%) attained stable disease for a disease control rate of 80%. Conclusions: Addition of TTI-621 to doxorubicin showed promising clinical activity and a favorable safety profile among pts with advanced LMS, including those with prolonged exposure to TTI-621 ( > 360 d). Clinical trial information: NCT04996004 .

A multicenter phase II trial of anti-EGFR-immunoliposomes loaded with doxorubicin in patients with advanced triple negative breast cancer

Advanced triple negative breast cancer (TNBC) is an aggressive, but initially chemo-sensitive disease. The prognosis is poor and more than three quarters of patients experience progression 12 months after the initiation of conventional first-line chemotherapy. Approximately two thirds of TNBC express epidermal growth factor receptor 1 (EGFR). We have developed an anti-EGFR targeted nanocontainer drug by inserting anti-EGFR antibody fragments into the membrane of pegylated liposomes (anti-EGFR-ILs-dox). The payload consists of doxorubicin, a standard drug for TNBC. In a first-in-human phase I trial in 26 patients with various advanced solid malignancies, anti-EGFR-ILs-dox has shown little toxicity and encouraging efficacy. In this single-arm phase II trial, we assessed the efficacy of anti-EGFR-ILs-dox as first-line therapy in patients with advanced, EGFR + TNBC. The primary endpoint was progression-free survival at 12 months (PFS12m). Secondary endpoints included overall response rate (ORR), duration of response (DOR), time to progression (TTP), overall survival (OS) and adverse events (AEs). 48 patients received anti-EGFR-ILs-dox 50 mg/m2 iv, on day one of a 28 days-cycle until progression. The Kaplan–Meier estimate for PFS12m was 13% (one-sided 90% CI 7%, 95% CI [5%, 25%]), median PFS was 3.5 months (95% CI 1.9, 5.4). The trial has not reached its primary endpoint. There were no new toxicity signals. Based on these results, anti-EGFR-ILs-dox should not be further developed for TNBC. It remains an open question whether anti-EGFR-ILs-dox would offer more opportunities in other EGFR-expressing malignancies, where targeting this receptor has already shown anticancer effects.Trial registration: This trial was registered at clinicaltrials.gov: NCT02833766. Registered 14/07/2016.

Brightline-1: phase II/III trial of the MDM2-p53 antagonist BI 907828 versus doxorubicin in patients with advanced DDLPS.

Dedifferentiated liposarcoma (DDLPS) is a rare, aggressive liposarcoma associated with poor prognosis. First-line treatment for advanced/metastatic DDLPS is systemic chemotherapy, but efficacy is poor and toxicities substantial. Most DDLPS tumors have amplification of the MDM2 gene, which encodes a negative regulator of the p53 suppressor protein. BI 907828 is a highly potent, oral MDM2-p53 antagonist that inhibits the interaction between p53 and MDM2, thereby restoring p53 activity. BI 907828 has shown promising activity in preclinical studies and in a phase Ia/Ib study in patients with solid tumors, particularly those with DDLPS. This manuscript describes the rationale and design of an ongoing multicenter, randomized, phase II/III trial (Brightline-1; NCT05218499) evaluating BI 907828 versus doxorubicin as first-line treatment for advanced DDLPS.

64P Tertiary lymphoid structure and efficacy of doxorubicin in patients with soft tissue sarcoma: The Centre Léon Bérard experience

64P Tertiary lymphoid structure and efficacy of doxorubicin in patients with soft tissue sarcoma: The Centre Léon Bérard experience

A post hoc analysis of the EPAZ trial: The role of geriatric variables in elderly soft tissue sarcoma patients on toxicity and outcome

ObjectiveThe EPAZ study (NCT01861951) showed recently that pazopanib was non-inferior to doxorubicin in patients ≥60 years treated in first line for advanced soft tissue sarcoma . The current post-hoc analysis aimed to assess the prognostic impact of frailty. MethodsGeriatric assessments were evaluated at baseline. Age >75 years, liposarcoma, ECOG = 2, G8 ≤14, instrumental activities of daily living (IADL) ≥1 and Charlson Comorbidity Index ≥2 were tested for their impact on progression-free survival (PFS), overall survival (OS), CTCAE grade 3/4 adverse events (AEs) or serious AEs (SAEs), using univariate and multivariate analysis models. Resultsunivariate analysis showed an increased risk of grade 3/4 AEs and SAEs for ECOG = 2, G8 score ≤14 or IADL ≥1, independent of treatment. The multivariate analysis exhibited for pazopanib a significantly reduced risk for grade 3/4 AEs (HR 0.53; p = 0.033), and in patients with G8 ≤14 an increased risk for SAEs (HR 2.67; p = 0.011).In the multivariate analysis, G8 ≤14 was a negative prognostic factor for PFS (HR 1.82; p = 0.009) and IADL ≥1 for OS (HR 2.02; p = 0.007). ECOG = 2 was the strongest negative predictor for PFS (HR 4.39; p = 0.001) and OS (HR 3.74; p = 0.004). Neither age nor Charlson Comorbidity Index showed any impact on PFS, OS, incidence of grade 3/4 AEs or SAEs. ConclusionsThis post hoc analysis demonstrated that age is not a denominator for outcome or toxicity in elderly patients with soft tissue sarcoma . Instead, geriatric and functional assessments should be used to counsel patients and tailor therapy to individual needs. Moreover, pazopanib has a reduced risk for grade 3/4 AEs compared to doxorubicin.

Trabectedin plus pegylated liposomal doxorubicin in patients with disease progression after PARP inhibitor maintenance: a real-life case–control study

ObjectivePoly (ADP-ribose) polymerase (PARP) inhibitor resistance is problematic in epithelial ovarian cancer management and sequencing strategies may be performed to overcome this issue. In this context, our study evaluated the...

Triptolide promotes ferroptosis by suppressing Nrf2 to overcome leukemia cell resistance to doxorubicin.

Doxorubicin (DOX) is an extensively used chemotherapeutic drug to treat leukemia. However, there remains a pivotal clinical problem of resistance to DOX in patients with leukemia. Erythroid 2‑related factor2 (Nrf2) is a master regulator of antioxidation response which serves a critical role in maintaining cellular oxidative homeostasis. However, whether Nrf2 is involved in DOX resistance is not totally clear. It is well‑documented that triptolide, a widely used drug to treat autoimmune disorders, possesses anti‑cancer activities, yet whether triptolide affects leukemia cell sensitivity to DOX remains to be elucidated. The present study aimed to determine the role of triptolide‑mediated downregulation of Nrf2 in regulating leukemia cell ferroptosis and resistance to DOX. For this purpose, low‑dose DOX was used to establish DOX‑resistant K562 cells and HL‑60 cells. Nrf2 mRNA and protein expression were examined by quantitative PCR and western blotting assays. The effects of triptolide on leukemia cell viability, reactive oxygen species (ROS) levels, or lipid oxidation were determined by CCK8 assay, DCFH‑DA assay, or BODIPY 581/591 C11 assay, respectively. The results show that Nrf2 expression was significantly upregulated in DOX‑resistant leukemia cells and clinical leukemia samples. Silencing of Nrf2 significantly sensitized leukemia cells to DOX. Furthermore, it was demonstrated that triptolide inhibited Nrf2 expression and induced leukemia cell ferroptosis, as evidenced by increased ROS levels and lipid oxidation as well as decreased glutathione peroxidase4 expression. Ectopic expression of Nrf2 significantly rescued triptolide‑induced leukemia cell ferroptosis. Notably, the present study showed that triptolide re‑sensitized DOX‑resistant leukemia cells to DOX. In conclusion, the present study indicated that Nrf2 served a critical role in leukemia cell resistance to DOX and triptolide‑induced ferroptosis and suggested a potential strategy of combination therapy using triptolide and DOX in leukemia treatment.

Efficacy and safety of sintilimab plus doxorubicin in advanced soft tissue sarcoma: A single-arm, phase II trial.

Background: Chemoimmunotherapy is safe and efficacious in treating many types of malignant tumors. However, clinical data demonstrating the effect of this combination treatment in patients with metastatic soft tissue sarcoma (STS) are currently limited. This study evaluated the safety and efficacy of a programmed cell death protein 1 (PD-1) inhibitor plus doxorubicin in patients with advanced STS who failed previous systemic therapy. Methods: This was a single-center, single-arm, open-label phase II trial. Patients with unresectable or metastatic STS who had previously failed systemic therapy were enrolled. Patients received up to six cycles of doxorubicin and sintilimab (a PD-1 inhibitor), while sintilimab treatment continued for up to 2years. Primary outcomes were objective response rate (ORR) and safety. Univariate Cox proportional hazards model was used to analyze the relationship between clinicopathological parameters and progression-free survival (PFS). Results: A total of 38 patients (20 men and 18 women) were enrolled in this study. The overall ORR was 39.5%, disease control rate was 71.1%, and the median PFS was 4.5 months [95% confidence interval (CI), 3.0-8.5months]. The adverse events (AEs) associated with the combined treatment were mild, manageable, and well-tolerated. The most common grade 3 or higher AEs were hematologic, including leukopenia (21.1%), anemia (18.4%), and thrombocytopenia (18.4%). Patients with undifferentiated pleomorphic sarcoma (UPS) or dedifferentiated liposarcoma had a significantly longer PFS than those with other pathological subtypes [hazard ratio (HR) = 0.42, 95% CI 0.21-0.83; p = 0.013]. There was no significant difference in the median PFS between patients who had previously received anthracycline-based chemotherapy and those who had not (HR = 0.74, 95% CI 0.34-1.58, p = 0.43). Conclusion: Sintilimab plus doxorubicin is a safe and promising treatment for patients with advanced STS who have failed previous systemic therapy (including anthracycline-based chemotherapy). The efficacy of this combination therapy in UPS and dedifferentiated liposarcoma is superior to that in other sarcomas. Clinical Trial Registration: https://www.chictr.org.cn, registration number: ChiCTR1900027009.

Abstract 5208: Circulating T cell: B cell: NK cell axis associated with response to pembrolizumab plus doxorubicin in patients with metastatic triple negative breast cancer

Abstract Introduction: The use of immune checkpoint inhibitors (ICI) in combination with chemotherapy is now standard of care for patients with programmed death ligand 1-positive (PD-L1+) metastatic triple negative breast cancer (mTNBC). However, the mechanisms of response to ICIs are still poorly understood in patients with mTNBC. Here we investigate immune correlates of response in patients with mTNBC treated with programmed cell death protein 1 (PD-1) receptor-targeting pembrolizumab and doxorubicin (n=9). Methods: Patients received pembrolizumab and doxorubicin every 3 weeks for a total of 6 cycles followed by pembrolizumab maintenance until disease progression. Objective response rates (ORR per RECIST 1.1) were: N=1 complete response (CR), N=4 partial responses (PR), N=3 stable disease (SD), and N=1 progression of disease (PD). Baseline tumor biopsies were collected for PD-L1 (22C3 antibody) and TILs analysis, and peripheral blood was collected for immune correlatives. Circulating peripheral blood mononuclear cells (PBMCs) were assessed by high parameter flow cytometry with samples collected at timepoints cycle 1 day 1 (C1D1), cycle 2 day 1 (C2D1), and cycle 3 day 1 (C3D1) Results: No association between response and tumor infiltrating lymphocyte (TIL) scoring or PD-L1 expression were observed. Circulating exhausted CD8+ T cells (PD-1 high CD39+) were identified at baseline in all patients, with the patient with PD having a low frequency of exhausted CD8+ T cells (0.08% in PD vs. 0.3% mean in CR/PR/SD) at baseline. In the patient with PD, the following results were observed relative to other patients: high levels of antibody-secreting B cells (ASC, 15.2% in PD vs. 1.5% mean in CR/PR/SD), CD4+ follicular helper T cells (Tfh, 8.47% PD vs. 2.6% mean in CR/PR/SD), and terminally differentiated NK cells (11.0% PD vs. 6.3% mean CR/PR/SD) at baseline. From baseline to C2D1, the patient who achieved CR demonstrated robust expansion of exhausted CD8+ T cells (4.4-fold change in CR vs. 1.4-fold change in PR/SD/PD). Conclusion: Our data suggests that both baseline immune profile ‘setpoints’ and dynamic remodeling of immune features, including expansion of exhausted CD8+ T cells, are associated with response to ICIs in patients with mTNBC. Lack of response to ICIs is defined not only by a lack of CD8+ T cell expansion, but also by high levels of circulating ASCs, Tfh, and terminal NK cells at baseline. Additional studies to further explore and validate features of this T cell: B cell: NK cell axis and response to ICIs in patients with mTNBC are ongoing. Citation Format: Colt A. Egelston, Weihua Guo, Peter P. Lee, Susan E. Yost, James R. Waisman, Yuan Yuan. Circulating T cell: B cell: NK cell axis associated with response to pembrolizumab plus doxorubicin in patients with metastatic triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5208.

TTI-621-03: A phase I/II study of TTI-621 in combination with doxorubicin in patients with unresectable or metastatic high-grade leiomyosarcoma (LMS).

TPS11593 Background: Doxorubicin is a standard of care agent for patients with advanced soft tissue sarcoma, with a response rate of around 15%, progression-free survival of 5-7 months and cumulative cardiac toxicity that limits its use. TTI-621 is a recombinant soluble fusion protein that combines the N-terminal portion of human SIRPα (the binding domain for CD47) with the Fc region of human IgG1, generating a decoy receptor for CD47 on the surface of tumor cells that both over-rides CD47-mediated inhibition of phagocytosis and provides a pro-phagocytic stimulation. Many solid tumors express high levels of CD47 which is associated with poor prognosis, thought to be the result of CD47-mediated inhibition of macrophage phagocytosis and escape of immune-mediated clearance. Interruption of the CD47-SIRPα signaling pathway using monoclonal antibodies to CD47 has shown anti-tumor activity in animal models and in some early clinical trials. The combination of doxorubicin with CD47-targeted antibodies results in enhanced anti-tumor activity and increased macrophage-mediated cell killing in animal models and macrophage-mediated phagocytosis of cancer cell lines in vitro, suggesting that combining TTI-621 with doxorubicin might be more effective than doxorubicin alone in tumor types that express CD47 and have high numbers of macrophages, such as LMS. Thus, a Phase 1/2 study was initiated to evaluate this combination in patients with advanced soft tissue sarcoma, including LMS. Methods: TTI-621-03 is a Phase 1/2, open-label study of TTI-621 in combination with doxorubicin in patients with anthracycline-naïve disease. The Phase 1 dose escalation evaluates doses of TTI-621 (0.2 to 2.0 mg/kg) in combination with doxorubicin at 75 mg/m2 in patients with high-grade soft tissue sarcomas. Expansion cohorts will evaluate TTI-621 (0.2 and 2.0 mg/kg) with doxorubicin in patients with LMS, with pathology confirmed at a central laboratory. The primary goals of this study are evaluation of safety of TTI-621 administered in combination with standard-of-care doxorubicin and to further evaluate clinical activity (ORR, PFS, OS), safety, PK and patient-reported quality of life in the LMS subpopulation. The dose escalation portion of the study has been completed without DLT. Enrollment to the expansion portion of the study is underway. Clinical trial information: NCT04996004.

Phase I trial combining pembrolizumab and doxorubicin in patients with metastatic triple negative breast cancer.

e13071 Background: Pembrolizumab (pembro) in combination with chemotherapy (chemo) has recently become standard of care in patients with programmed death-ligand 1 (PD-L1) positive metastatic triple negative breast cancer (mTNBC). Optimal chemo partner with pembro remains debatable. The current phase I study evaluated the safety and efficacy of doxorubicin (dox) + pembro in anthracycline-naïve mTNBC patients (NCT02648477). Methods: Patients with mTNBC, no prior anthracycline, and ≤2 lines of prior chemo for metastatic disease were enrolled. Patients received pembro 200mg IV and 50-60 mg/m2 dox IV every 3 weeks x6, followed by pembro maintenance until progression or unacceptable toxicity. The primary objectives were safety and objective response rate (ORR per RECIST 1.1). For the safety lead-in, we employed a 3-at-risk rolling design. Results: Ten patients were accrued between March 2016 and November 2019. The trial stopped early due to poor accrual. The first 3 patients received dox at 50mg/m2 without dose limiting toxicities and dose was escalated to 60mg/m2 for the remaining patients. Median age was 62 years (range 41-87). Grade ≥ 3 AEs were: 4 neutropenia, 2 dyspnea, 2 fatigue, 1 oral mucositis, 1 hyponatremia, 1 acidosis, 1 alkalosis, 1 hypotension and 1 respiratory failure. One patient (age 87) received 1 dose of therapy, developed neutropenia and respiratory failure which led to death, and was not eligible for response assessment. 1 patient did not have RECIST measurable disease. Two patients had dose delay (1 G3 neutropenia and 1 G2 upper airway infection). 1 patient had dose reduction due to G3 fatigue. Immune toxicity was consistent with known pembro toxicity. Of 9 evaluable patients, responses were : 1 CR, 3 PR, 2 UPR, 2 SD and 1 PD, which translated to a best ORR of 67% (95% CI, 13.7%, 78.8%). CBR at 6 mo was 56% (95% CI 21.2%, 86.3%). Median follow-up time was 34.6 mo (range 14.5 - 45.4 mo). Median PFS was 5.2 mo (95% CI 4.7, NA); and median OS was 15.6 mo (95% CI 13.3, NA). Eight patients had PD-L1 (22C3) testing: 4 positive and 4 negative. No association between the PD-L1 status and response was observed. Conclusions: The combination of pembro+dox was well tolerated and had modest activity in anthracycline-naïve patients with mTNBC. The finding needs to be further confirmed with future study. Clinical trial information: NCT02648477.