Breast cancer is the largest cause of cancer deaths in women worldwide. In around 75% of breast cancers, the hormone oestrogen plays a key part in tumour growth.
Evgen sponsored a Phase II trial [STEM – SFX-01 in the Treatment and Evaluation of Metastatic Breast Cancer] in patients with ER+, HER2-ve metastatic breast cancer (mBC). The study enrolled 46 patients with oestrogen-positive mBC who had all previously received treatment with either tamoxifen, an aromatase inhibitor (AI) or fulvestrant. Prior to entry to the STEM trial, patients previously responded to their current hormone therapy for at least six months but then presented with progressive disease, thereby demonstrating the start of resistance to the hormone therapy.
Once entered into the trial, patients continued to receive their failing hormone therapy in addition to SFX-01 and had regular scans through to week 24. Patients discontinued the trial when one of the scans shows disease progression, or at week 24. Those patients who did not progress by week 24 were allowed to continue to receive treatment in an extension phase until disease progression.
Positive results were announced in March 2019 and the headlines were:
- Evidence of anti-cancer activity via tumour shrinkage and disease stabilisation.
- 24% of patients showed a durable clinical benefit for at least six months, despite the late stage of disease and patients’ established resistance to hormone therapy. Of these, five patients received SFX-01 for over 12 months and one patient remained on treatment for over 18 months.
- A favourable side effect profile for an anti-cancer drug.
See full STEM information
, including posters and presentations.
Evgen is continuing investigation into how SFX-01, in combination with other treatments, can improve outcomes for patients with HR+ breast tumours that have become resistant to other therapies. This includes research into STAT3 and pSTAT3, a protein that controls transcription of information from DNA to messenger RNA; and SHP2, a non-receptor protein tyrosine phosphatase that is associated with many cancers including breast cancer.