Yu Xia

Retrospective study of elderly patients with advanced ovarian cancer who did not undergo surgery

Abstract Objective To evaluate the clinical outcomes of elderly patients with advanced ovarian cancer who did not undergo surgery and received chemotherapy with or without maintenance therapy. Methods We retrospectively analyzed the clinical data of 15 patients with advanced high-grade serous ovarian cancer who were treated at our hospital between 2018 and 2023. These patients either had multiple comorbidities or refused surgery. Data collected included patient demographics, treatment regimens, chemotherapy cycles, clinical response, progression-free survival (PFS), and overall survival (OS). Results The median age of the patients was 73 years (range, 50-86 years). Fourteen patients received platinum-based chemotherapy combined with paclitaxel or liposomal doxorubicin, with or without bevacizumab, for 3 to 6 cycles. Twelve patients who achieved disease control received PARP inhibitor maintenance therapy. The overall response rate (ORR) was 80.0%, or 12/15 patients achieved partial response (PR); nobody achieved complete response. The disease control rate (DCR) was 100%. The median PFS1 was 19.0 months (95% CI, 11.85-26.15), and the median PFS2 was 10 months. The 3-year OS rate was 65.2%, with a median OS of 57.0 months (95% CI, 13.00-100.99). Conclusions Chemotherapy with or without bevacizumab, followed by PARP inhibitor maintenance therapy, is a viable alternative for elderly or surgically ineligible patients with advanced ovarian cancer. The findings of this study should be considered exploratory and require validation through large-scale studies.

Niraparib restricts intraperitoneal metastases of ovarian cancer by eliciting CD36-dependent ferroptosis

Ovarian cancer (OC) is prone to peritoneum or omentum dissemination, thus giving rise to the formidable challenge of unresectable surgery and a dismal survival rate. Although niraparib holds a pivotal role in the maintenance treatment of OC, its effect on suppressing metastases during primary intervention remains enigmatic. Recently, we initiated a prospective clinical study (NCT04507841) in order to evaluate the therapeutic efficacy of neoadjuvant niraparib monotherapy for advanced OC with homologous recombination deficiency. An analysis of patient tumor burden before and after the niraparib challenge showed a remarkable vulnerability of OC intraperitoneal metastases to niraparib exposure. This killing capacity of niraparib was closely associated with the accumulation of fatty acids within the abdomen, which was confirmed by the increased susceptibility of tumor cells to niraparib treatment in the presence of fatty acids. In the context of abundant fatty acids, niraparib elevated intracellular levels of fatty acids and lipid peroxidation, leading to subsequent tumor cell ferroptosis in a p53 and BRCA-independent manner. Notably, under niraparib exposure, a critical fatty acid transporter CD36 was dramatically upregulated in tumors, facilitating excessive uptake of fatty acids. Pharmacological inhibition of either ferroptosis or CD36 impaired the anti-tumor activity of niraparib both in vitro and in murine intraperitoneal ID8 tumor models. Our findings demonstrate ferroptosis as a novel mechanism underlying the regression of OC metastases induced by niraparib, thereby offering tantalizing prospects for the frontline application of this agent in the management of OC.

Bepotastine Sensitizes Ovarian Cancer to PARP Inhibitors through Suppressing NF-κB–Triggered SASP in Cancer-Associated Fibroblasts

Abstract Therapy-induced senescence (TIS) is common in tumor cells treated with PARP inhibitors (PARPis) and can serve as a promising target for improving PARPi efficacy. However, whether stromal components within the tumor microenvironment undergo TIS caused by PARPis and contribute to consequential treatment failure remain unclear. We previously revealed that PARPis triggered a senescence-like secretory phenotype in stromal fibroblasts. Here, we further explored PARPi-induced senescence in the stroma, its contribution to PARPi resistance, and opportunities to leverage stromal TIS for improved PARPi sensitivity. In this study, we demonstrated that tumor tissues from patients treated with neoadjuvant PARPis showed a significant senescence-like phenotype in the stroma. Moreover, PARPi-induced senescent cancer-associated fibroblasts (CAFs) displayed a senescence-associated secretory phenotype (SASP) profile that was sufficient to induce tumor resistance to PARPis in both homologous recombination–deficient (HRD) and –proficient ovarian cancer cells. Using the GLAD4U database, we found that bepotastine, an approved H1-antihistamine, inhibited the SASP of PARPi-primed CAFs at clinical serum concentrations. We further demonstrated that bepotastine attenuated fibroblast-facilitated tumor resistance to PARPis in three-dimensional organotypic cultures and HRD-positive patient-derived xenograft models. Mechanistically, bepotastine suppressed PARPi-triggered SASP by inhibiting NF-κB signaling independent of the histamine H1 receptor. Taken together, our results highlight the importance of stromal TIS and SASP in PARPi resistance, and targeting SASP with bepotastine may be a promising therapeutic option for improving PARPi sensitivity in ovarian cancer.

Mitigating T cell DNA damage during PARP inhibitor treatment enhances antitumor efficacy

Poly(ADP-ribose) polymerase inhibitors (PARPis) are a class of agents targeting DNA damage repair that have become standard therapy for epithelial ovarian cancer (EOC) and multiple other solid tumors. In addition to targeting DNA damage repair, PARPis actively modulate antitumor immune responses, with efficacy being partially dependent on T cell activity. Here, we found that patient T cells sustain DNA damage during PARPi treatment, which reduces treatment efficacy. Leveraging paired pre- and posttreatment tumor samples from a clinical trial of patients with EOC treated with neoadjuvant niraparib as monotherapy, we showed that the PARPi caused DNA damage, slowed proliferation, and increased apoptosis in T cells, which we validated both in vitro and in mouse models. A genome-wide CRISPR (clustered regularly interspaced short palindromic repeats) knockout screen in primary human T cells identified PARP1 as the principal mediator of PARPi-induced T cell death. T cell–specific deletion of PARP1 or mutating Parp1 at its binding sites in transgenic mice led to reduced T cell DNA damage during PARPi treatment, resulting in improved efficacy of PARPis, alone or in combination with immune checkpoint inhibition. We then engineered PARPi-tolerant CAR T cells using cytosine base editing, which decreased PARPi-induced PARP1 trapping and led to reduced PARPi-induced DNA damage, resulting in superior antitumor efficacy in xenograft models compared with parental CAR T cells. This study highlights the relevance of PARPi-induced DNA damage to T cells and suggests opportunities to improve the efficacy of PARPis as monotherapy or in combination with immunotherapy.

Cadonilimab Combined with Chemotherapy with or without Bevacizumab as First-Line Treatment in Recurrent or Metastatic Cervical Cancer (COMPASSION-13): A Phase 2 Study

Abstract Purpose: Immune checkpoint inhibitors (ICI) have been a potential treatment option for patients with cervical cancer in several clinical studies. We investigated the safety and efficacy of cadonilimab, a bispecific antibody targeting PD-1 and CTLA-4, plus standard therapy for the first-line treatment of R/M CC (recurrent and/or metastatic cervical cancer). Patients and Methods: Eligible patients were assigned to 3 cohorts: cohort A-15 (cadonilimab 15 mg/kg every 3 weeks (Q3W) plus chemotherapy), cohort A-10 (cadonilimb 10 mg/kg Q3W plus chemotherapy), and cohort B-10 (cadonilimab 10 mg/kg Q3W plus chemotherapy and bevacizumab). They received the corresponding treatments until disease progression, unacceptable toxicity, withdrawal of consent, or investigator decision. The primary objective was safety; the secondary endpoints included objective overall response (ORR), duration of response, disease control rate, progression-free survival, and overall survival. This study is registered with ClinicalTrials.gov (NCT04868708). Results: As of February 13, 2023, treatment-related adverse events (TRAE) occurred in 45 (100.0%) patients. Grade ≥3 TRAEs were reported in 33 (73.3%) patients. Immune-related adverse events (irAE) occurred in 29 (64.4%) patients and grade ≥3 irAEs were observed in 9 (20.0%) patients. Seven (15.6%) of 45 patients permanently discontinued cadonilimab treatment due to TRAEs. One death due to hemorrhagic shock occurred in cohort B-10. Among 44 patients who underwent at least one post-baseline tumor assessment, the ORR was 66.7% in cohort A-15, 68.8% in cohort A-10, 92.3% in cohort B-10, and 79.3% in cohorts A-10 and B-10 combined. Conclusions: Cadonilimab combined with standard therapy was acceptable, with encouraging antitumor activity in patients with R/M CC.

Niraparib for the Neoadjuvant Treatment of Unresectable Ovarian Cancer

This is a prospective, interventional, single-arm, open-label, phase II study to evaluate the safety and efficacy of niraparib monotherapy as neoadjuvant therapy in patients with advanced ovarian cancer, primary peritoneal cancer, fallopian tube cancer ((FIGO stage III or IV), who had low likelihood of achieving R0 cytoreduction by imaging assessment or laparoscopic evaluation, or cannot tolerate PDS by poor conditions.