Cancer vaccine: galinpepimut-S Strong Effective on type 2 solid tumors

Cancer vaccine: Galinpepimut-S Strong Effective on type 2 solid tumors. The super cancer vaccine galinpepimut-S combined with checkpoint inhibitors has a strong effect on the treatment of type 2 solid tumors!

SELLAS Life Sciences Group Inc (SELLAS Life Sciences Group Inc) is a late-stage clinical biopharmaceutical company dedicated to the development of new cancer immunotherapies for a variety of cancer indications. Recently, the company announced the clinical data of a new cancer vaccine galinpepimut-S (GPS) combined with immune checkpoint inhibitors in the treatment of two different types of WT1-positive (WT1+) advanced solid tumor patients, these patients have exhausted their standard treatment options .

GPS is a cancer vaccine targeting WT1 (Wilms Tumor 1) protein. WT1 is one of the most widely expressed cancer antigens and has been listed by the National Cancer Institute (NCI) as the primary target of cancer immunotherapy.

The first study is the Phase 1/2 “basket” study of GPS combined with anti-PD-1 therapy Keytruda (generic name: pembrolizumab, pembrolizumab), which is based on the clinical contract with Merck Pilot cooperation and supply agreements are carried out.

The first group of assessed patients (n=8) was diagnosed with second-line or third-line WT1(+) relapsed or refractory metastatic ovarian cancer. The median follow-up data of 9.4 weeks showed that the disease control rate of GPS+Keytruda combination therapy (DCR= The overall response rate [ORR] + stable disease rate) was 87.5%. In this refractory patient group, at the first evaluation time point 6 weeks after initiation of treatment, 100% of patients had no disease progression.

During the screening period, through immunohistochemistry (IHC) testing, the positive rate of WT1 in ovarian cancer patients was about 70%. Of the 8 evaluable patients, 6 continued to receive GPS+Keytruda treatment. Currently, the study is still undergoing patient enrollment, and the goal is a total of 20 patients. More mature clinical and immunobiological data are expected to be released at the end of the second quarter of 2021.

The second study is a phase 1 investigator-sponsored (IST) study of GPS combined with anti-PD-1 therapy Opdivo (Nivolumab, nivolumab) in the treatment of patients with malignant pleural mesothelioma (MPM). These patients have relapsed after receiving first-line to third-line standard therapies and are refractory to these therapies. The first group of evaluable patients (n=3) had a median progression-free survival (PFS) of at least 10 weeks after starting treatment.

In patients with primary refractory MPM, considering the current lack of effective treatments, any extension of PFS beyond 8 weeks is considered clinically significant. All patients have epithelioid variants of MPM, which is a tumor that universally expresses WT1. In addition, in this study, GPS was found to have appropriate immunogenicity, resulting in antigen (WT1) specific CD4+T memory cell response 3 months after the start of treatment.

Currently, the study is enrolling more MPM patients; it is expected that the enrollment of the study will be completed by the end of the second quarter of 2021 (total number of targets n=10) and more mature clinical and immunobiological data will be released.

In these two studies, the safety of the combined use of GPS and checkpoint inhibitors is similar to that of the use of checkpoint inhibitors alone, except that a low-grade, short-lived local reaction was added to the site where GPS was injected. The GPS clinical research is consistent.

Jeffrey S. Weber, Chairman of the SELLAS Scientific Advisory Board, commented: “These early data confirm the tolerability profile in the early GPS studies, which is one of the main endpoints of these solid cancer trials, in various cancer indications, even in This is also true in the most difficult-to-treat patients who have previously received multiple regimens. These safety findings are accompanied by promising signs of efficacy in patients with advanced metastatic cancer who are extremely challenging even with checkpoint inhibitor monotherapy. “

Dragan Cicic, senior vice president of clinical development at SELLAS, said: “We are now encouraged by the data from the joint GPS and checkpoint inhibitor studies and look forward to obtaining more data from these studies. We now have support to further expand the potential indications of GPS to Solid tumors with high WT1 positive rate.

Previous studies have shown that GPS can activate multiple epitopes, extensive cross-reactions along the full length of the WT1 protein, suggesting epitope proliferation and immune-mediated cancer cell destruction, which are features of an effective cancer vaccine. The scientific principle of combining GPS with checkpoint inhibitors is the synergy of immunobiology and pharmacodynamics between the two drugs. The checkpoint inhibitor reduces the negative impact of the tumor microenvironment and allows the patient’s own immune cells to pass GPS specifically sensitizes WT1, invades and destroys cancer cells. “

GPS is a cancer vaccine targeting WT1 (Wilms Tumor 1) protein. It is composed of 4 polypeptide chains and has as many as 25 epitopes. It can stimulate a strong immune response of the own immune system to WT1 antigen. It is similar to other therapies. The combination can kill the tumor cells remaining in the body during the remission period and strengthen the immune monitoring effect of the immune system on tumor cells. Previously, the US FDA has granted GPS fast-track qualifications for the treatment of multiple types of cancer.

WT1 is one of the most widely expressed cancer antigens and has been listed by the National Cancer Institute (NCI) as the primary target for cancer immunotherapy. Importantly, because WT1 antigen is overexpressed in a variety of hematological malignancies and solid tumor cells, but not found in most normal tissues, GPS is expected to become a widely applicable immunotherapy for more than 20 different Hematological malignancies and solid tumors. (For the characteristics and latest research progress of cancer vaccine GPS, click for details: galinpepimut-S (GPS).

Currently, SELLAS is developing GPS for multiple tumor indications, including acute myeloid leukemia (AML), malignant pleural mesothelioma (MPM), multiple myeloma (MM), ovarian cancer, etc. In clinical studies, GPS has shown positive efficacy data in the treatment of AML, MPM and MM, and has produced a strong immune response (CD4+/CD8+) against WT1 antigen in the body, and has a wide range of HLA adaptability.

According to the information published on the website, SELLAS is reaching a strategic cooperation with tumor immunotherapy giants Merck and Bristol-Myers Squibb to evaluate the therapeutic potential of GPS combined with Opdivo and Keytruda. In addition, the company has also reached a strategic cooperation with Roche to evaluate the potential of another asset, NeuVax (nelipepimut-S) combined with Herceptin (trastuzumab, trastuzumab) to treat HER2 1+/2+ breast cancer.

(source:internet, reference only)

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