Novel HER2-hICD Vaccine to be Investigated for Treatment of HER2-Low Breast Cancer

Treatment with AST-301 will be explored in patients with HER2-low breast cancer in the phase 2 Cornerstone-011 study.

Treatment with the novel HER2-hICD vaccine, AST-301, will be assessed in patients with HER2-low breast cancer in the phase 2 Cornerstone-001 trial (NCT05163223) following the FDA’s clearance of an investigational new drug application.1

According to an announcement by Aston Sci. Inc., the launch of FDA clearance and the launch of the study comes after the approval of the agent in Australia and Taiwan.

"It is a remarkable milestone that is definitely a leap forward for us in the cancer vaccine clinical development field. Based on the significant regulatory value of the phase 1 clinical trial, including more than 10 years of long-term survival data, we have reinforced regulatory-required data which complies to the latest guidelines of therapeutic cancer vaccine, and the United States FDA has fully reviewed and approved it,” said the regulatory affairs director of Aston Sci. Inc., in a press release.

Cornerstone-001 is a placebo-controlled, randomized study designed to evaluate the efficacy and safety of AST-301 in patients with HER2-low breast cancer that is hormone-receptor negative and who have residual disease after neoadjuvant therapy.

Patients in the study will be randomly assigned 1:1 to receive either AST-301 with recombinant human granulocyte-macrophage colony-stimulating factor (rhuGM CSF) and standard adjuvant therapy in the experimental arm or placebo with rhuGM CSF and standard adjuvant therapy in the control arm.1,2

Standard adjuvant therapy consists of pembrolizumab (Keytruda) and capecitabine. Adjuvant therapy in the study will be given 3 times every 3 weeks with a booster at 24 weeks in accordance with the guideline recommendations. AST-301 and rhuGM CSF will also be administered every 3 weeks for 3 cycles with a booster at week 24.

The primary end point being assessed in the study is 2-year invasive disease-free survival. The secondary end points include AST-301-specific T-cell immune response, change in central memory T-cell populations, distant recurrence-free survival, and the number of patients with treatment-related adverse events.2

The eligibility requirements for the study state that patients must have residual invasive disease that is stage I-III, HER2-low expression without gene amplification, an ECOG performance status of 0 or 1, and adequate organ function. Patients are excluded from the study is they have a history of hypersensitivity to rhuGM CSFm, history of invasive malignancy with ≤ 5 years before first administration of investigational study treatment, history of autoimmune disease or inflammatory disease, active infection, or pregnancy. The study also excludes those who are receiving immune suppression therapy or have within ≤ 4 weeks before the first administration of investigation study treatment.

REFERENCES:

1. Aston Sci. receives IND approval from U.S. FDA for phase 2 clinical trial of the therapeutic cancer vaccine AST-301 in patients with HER2 1+/2+ breast cancer. News release. Aston Sci., Inc. September 1, 2022. Accessed September 2, 2022. https://bit.ly/3CNjodI

2. Therapeutic cancer vaccine (ast-301, pngvl3-hicd) in patients with breast cancer (Cornerstone001). ClinicalTrials.gov. Updated May 5, 2022. Accessed September 2, 2022. https://clinicaltrials.gov/ct2/show/NCT05163223