Malignant pleural effusion and/ or malignant ascites is generally defined by presence of malignant cells in the effusion fluid. The first-line therapies are mostly intrusive, medically demanding and inefficient, and therefore, it is important to study and develop new therapeutic option to address the unmet need.

This protocol for BSG-001 is developed for the treatment of malignant pleural effusion and/ or malignant ascites. BSG-001 is an immune-modulator primarily exerts its effect via Toll-like receptor.

The purpose of this study is to assess the safety and tolerability of BSG-001. All eligible subjects will receive BSG-001 for at least 12 weeks (3 cycles).

This study is a phase 1/2a, single arm study with main purpose to evaluate the safety, tolerability and efficacy of BSG-001 in subjects with cancer that causes an abnormal amount of fluid to collect between the thin layers of tissue (pleura) lining the outside of the lung and the wall of the chest cavity, namely malignant pleural effusion and/ or subjects with cancer that causes the accumulation of fluid in the peritoneal cavity, causing abdominal swelling, namely malignant ascites.

The study aims to recruit 9 - 18 subjects in phase 1, and once the safety, tolerability and the preliminary efficacy of BSG-001 reach an optimal target exposure for recommended dose (RD), phase 2a will be opened for enrolment of approximately 40 subjects.

Inclusion Criteria:

1. Histologically or cytologically documented malignant pleural effusion and/or malignant ascites OR morphological diagnosis of malignant pleural effusion and/or malignant ascites by CT or ultrasound
2. Histologically confirmed cancer
3. Malignant pleural effusion and/or malignant ascites clinically judged as not responsive to conventional systemic therapy(ies) for primary malignancy
4. Adequate liver and renal function as defined below:
5. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
6. Life expectancy of > 12 weeks
7. Willing and able to provide written, signed informed consent after the nature of the study has been explained, and prior to any research-related procedures
8. Females of childbearing potential must have a negative serum pregnancy test at screening and be willing to have additional serum pregnancy tests during the study.
9. Willing and able to comply with all study procedures

Exclusion Criteria:

1. Presence of > grade 3 active infection or gastric bleeding at the time of screening
2. Change in chemotherapy regimen within 28 days before Day 1 of study drug administration
3. Concurrent use of any investigational product (IP) or investigational medicine within 28 days before Day 1 of study drug administration
4. Symptomatic interstitial lung disease or inflammatory pneumonitis
5. Concurrent disease or condition which, in the opinion of the Investigator, would pose a risk to patient safety or interfere with study participation or interpretation of individual patient results
6. Breastfeeding at screening or planning to become pregnant (self or partner) at any time during study participation