FDA Fast Tracks BST02 for Liver Cancer

• BST02, a tumor-infiltrating lymphocyte (TIL) therapy using a patient's own immune cells, received a fast track designation from the FDA for all forms of liver cancer.

• This marks a significant advancement as the first TIL therapy to reach the clinical stage globally.

• An ongoing phase 1 trial (NCT06173726) of BST02 in China is enrolling patients with advanced liver cancer.

The T-cell therapy BST02 has been granted a fast track designation from the FDA for the treatment of patients with all forms of liver cancer, including those with hepatocellular carcinoma (HCC) and cholangiocarcinoma.¹

Previously in October 2023, an investigational new drug application was approved for BST02 for evaluation in a phase 1/2 clinical trial by the Center for Drug Evaluation. In January 2024, BST02 was also approved by the China National Drug Administration.

BST02 represents the first TIL cell therapy to progress to the clinical stage globally.

3d illustration of human body liver: © PIC4U - stock.adobe.com

About BST02

BST02 is a novel adoptive immune cell therapy based on the expansion of the patient's own TILs. The agent depends on the expansion of TILs derived from a patient’s cells and does not require high doses of interleukin-2. Additionally, BST02's ability to be cryopreserved represents a significant advancement in TIL therapy, eliminating travel and logistical complications from treatment.²

An open-label, single-arm, investigator-initiated phase 1 trial is currently ongoing and evaluating BST02 among patients with histologically or cytologically confirmed locally advanced or metastatic liver cancer including HCC.³

Enrollment in the study is open to patients aged 18-75 years old with intrahepatic bile duct carcinoma, and metastatic liver cancer with at least 1 measurable lesion per RECIST v1.1 criteria, an ECOG performance status of 0 or 1, Child-Pugh score of cirrhosis of 7 or fewer points, at least 3 months of expected survival time, and adequate organ and bone marrow function during the screening period or within 14 days prior to TIL sampling. Patients with HCC and cholangiocarcinoma must have stage B or C disease that is not amenable to local treatment. Those with metastatic liver cancer should not be eligible for radical surgery and patients with locally advanced liver cancer should have received frontline systemic therapy at minimum, be deemed unsuitable for, or refused such treatment after failure of prior therapy.

Moreover, those with metastatic disease are required to have experienced disease progression or intolerance on second- or later-line therapy, refused standard therapy, or received an inappropriate treatment recommendation according to the investigator, and patients must be fit enough to undergo at least 1 operation without radiation or other local treatment within 28 days to remove the tumor lesions with an estimated lesion volume of at least 8 cm³, excluding necrotic areas, for the preparation of BST02 cells.

Adverse effects (AE) related to prior therapy must have resolved to grade 1 or lower prior to tumor sampling, according to the Common Adverse Event Evaluation Criteria.

Once enrolled in the study, patients were treated with a single intravenous infusion of cyclophosphamide at a dose of 250 mg or 1.5 g/m² for 3 days prior to receiving an infusion of BST02 to stimulate lymphocyte proliferation. Patients will go through 2 periods: the main study period and the long-term follow-up period. In the main study period, patients will undergo a screening period, treatment and safety observation period, and follow-up period.

The primary end points being explored in the study are the occurrence and incidence of AEs, severe AEs, and dose-limiting toxicities.

The study has a primary completion date of December 5, 2026, and is ongoing in China.

REFERENCES

1. Biosyngen announces FDA fast track designation for BST02 in treatment of liver cancer. News release. Biosyngen. February 1, 2024. Accessed February 2, 2024. http://tinyurl.com/ymyb5vhn

2. Biosyngen’s BST02, the world’s first TIL therapy for liver cancer, is granted an IND approval by FDA. News release. Biosyngen. October 26, 2023. Accessed February 2, 2024. http://tinyurl.com/39u7wbww

3. Investigator-initiated phase I exploratory clinical study of the safety, tolerability, and efficacy of BST-2 injection in the treatment of locally advanced/metastatic liver cancer. ClinicalTrials.gov. Updated December 18, 2023. Accessed February 2, 2024. https://classic.clinicaltrials.gov/ct2/show/NCT06173726