Reverse HER2-negative Immune Resistant Breast Cancer (Resilire)

Fudan University

Status and phase

Enrolling

Phase 2

Conditions

HER2 Negative Breast Cancer

Treatments

Drug: Retinoic Acid

Drug: anti-PD-1 antibody and chemotherapy

Study type

Interventional

Funder types

Other

Identifiers

NCT06731140

2411307-7

Details and patient eligibility

About

This is a Phase II, open-label study evaluating the efficacy and safety of combined treatment (retinoic acid) with immune checkpoint inhibitor in HER2-negative breast cancer patients who progressed during previous immune checkpoint inhibitors.

Full description

This is a Phase II, open-label study evaluating the efficacy and safety of combined treatment (retinoic acid) with immune checkpoint inhibitors in metastatic HER2-negative breast cancer patients who progressed during or following previous immune checkpoint inhibitors. HER2-negative breast cancers include luminal breast cancers and triple-negative breast cancers.

Current clinical studies on immunotherapy for luminal breast cancer are limited, with inconsistent results across trials. The KEYNOTE-028 study reported an objective response rate (ORR) of only 12% for pembrolizumab in PD-L1-positive, previously treated advanced luminal breast cancer patients, demonstrating limited efficacy. The GIADA phase II trial revealed a pathological complete response (pCR) rate of 16.3% with neoadjuvant chemotherapy followed by immunotherapy in luminal breast cancer. Additionally, trials such as NCT02779751 and NCT03051659 also indicated limited clinical benefits from immunotherapy. However, the I-SPY2 platform showed that combinations like olaparib, paclitaxel, and immunotherapy or wP-AC chemotherapy with immunotherapy could improve pCR rates in high-risk patients. Despite advancements, immunotherapy benefits are limited in luminal breast cancer compared to other cancers, with advanced-stage patients more likely to develop resistance.

Recent clinical studies on advanced triple-negative breast cancer have shown that immunotherapy combined with chemotherapy demonstrates superior clinical efficacy compared to traditional chemotherapy alone. Phase III trials such as IMPassion130 and Keynote-522 have confirmed that PD-1/PD-L1 inhibitors used with chemotherapy significantly improve progression-free survival, overall survival, and pathological complete response rates. However, compared to other malignancies, triple-negative breast cancer patients still show relatively low overall response rates to immunotherapy: treatment-naïve patients achieve objective response rates of only 10-20% with immunotherapy monotherapy, though this improves to 56% when combined with chemotherapy, extending median progression-free survival to 7.2 months. Unfortunately, efficacy decreases significantly in later treatment lines, with objective response rates falling to just 10.6-15.9% after multiple previous treatments. Thus, strategies to overcome immunotherapy resistance or increase the sensitivity of immunotherapy efficacy are urgently needed for HER2-negative breast cancer patients.

The preclinical results of our center show that retinoic acid can enhance the anti-tumor immune response by promoting the peroxidation of macrophages, increasing the infiltration and function of cytotoxic CD8+ T cells, inhibiting the growth of tumors in mice. Based on the preclinical study, the investigators designed this study to enroll metastatic HER2-negative breast cancer patients who have progressed during or following immunotherapy, and to explore the efficacy of retinoic acid combined with immunotherapy at a clinical level, providing new strategies of combined treatment for HER2-negative breast cancer patients.

Enrollment

10 estimated patients

Sex

Female

Ages

18 to 70 years old

Volunteers

No Healthy Volunteers

Inclusion criteria

ECOG Performance Status of 0, 1, or 2
Metastatic or locally advanced, histologically confirmed luminal breast cancer (defined as: ER positive when immunohistochemistry shows >1% positive tumor cells, PR positive when >1% tumor cells are positive, and HER2 negative when scored as 0-1+ or when HER2 2+ shows no amplification by FISH or CISH) or triple negative breast cancer (defined as: ER negative when immunohistochemistry shows <1% positive tumor cells, PR negative when <1% tumor cells are positive, and HER2 negative when scored as 0-1+ or when HER2 2+ shows no amplification by FISH or CISH).
Radiologic/objective evidence of recurrence or disease progression after immunotherapy (combined with targeted therapy or chemo ) for metastatic breast cancer (MBC)
Adequate hematologic and end-organ function, laboratory test results, obtained within 14 days prior to initiation of study treatment.

For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures as outlined for each specific treatment arm

Measurable disease according to Response Evaluation Criteria in Solid Tumors v1.1 (RECIST v1.1)
have the cognitive ability to understand the protocol and be willing to participate and to be followed up.

Exclusion criteria

Symptomatic, untreated, or actively progressing CNS metastases
Active or history of autoimmune disease or immune deficiency
Significant cardiovascular disease
History of malignancy other than breast cancer within 5 years prior to screening, with the exception of those with a negligible risk of metastasis or death
Treatment with chemotherapy, radiotherapy, immunotherapy or surgery (outpatient clinic surgery excluded) within 3 weeks prior to initiation of study treatment.
Pregnancy or breastfeeding, or intention of becoming pregnant during the study
History of allergies to the drug components of this trial
History of eosinophilosis or mastocytosis
Patients who have been using oral steroid hormones for a long time will need to stop for 4 weeks if they have used them occasionally in the past