Evgen Pharma plc (LON:EVG), a clinical stage drug development company focused on the treatment of cancer and neurological conditions, has announced an encouraging interim update on STEM (SFX-01 in the Treatment and Evaluation of Metastatic Breast Cancer), the Company’s Phase II clinical trial in advanced breast cancer.
This interim update, which the Company is able to provide because the trial design is open label, comprises the first 20 patients to have completed the trial.
Patients recruited in STEM have previously responded to hormone therapy (tamoxifen, aromatase inhibitors or fulvestrant) for at least six months but have then been diagnosed with progressive disease, indicating secondary resistance to the hormone therapy. Patients in STEM continue on their hormone therapy but also receive SFX-01. They have six-weekly scans and are discontinued from the study as soon as a scan shows progressive disease or progress is evident on symptomatic grounds. The maximum period on the trial is 24 weeks; patients who respond to the drug can access SFX-01 after that time via a compassionate use programme.
It should be noted that this interim update should be interpreted with due caution as the final results of the trial may differ.
At this interim stage, in the opinion of the Principal Investigator, Dr Sacha Howell, and of the Company’s Chief Medical Advisor:
· SFX-01 is proving to be well tolerated with no safety concerns arising
· SFX-01 shows encouraging early signs of anti-tumour activity:
– Four patients had their disease stabilised (that is, having joined the trial with progressive disease their tumours stopped progressing) for the full duration of the study through to, and including, a favourable final scan result at week 24. Of these four patients, one also had a partial response which is a reduction in tumour size of at least 30% on one scan
– In addition to the above four patients, a further two patients had their disease stabilised through to, and including, the week 18 scan but then showed disease progression at the final week 24 scan. One of these two patients also demonstrated a partial response on one scan before disease progression was recorded at the final scan
All patients that have a favourable week 18 scan are registered in the compassionate use programme to ensure continuity of drug between the final week 24 scan and the scan result, which can be some time later. Those that have a favourable week 24 scan continue on the programme.
STEM, which will include up to 60 patients, remains on track to report around the end of 2018 with 14 sites having already recruited a total of 44 patients across the UK, Belgium, Spain and France. The 44 patients include the 20 patients in this interim update.
The primary endpoints of the study are: safety and tolerability, and clinical benefit rate at 24 weeks, that is, the proportion of patients with no disease progression after 24 weeks of therapy (this includes stable disease, partial response and complete response).
Putting this interim update into a clinical context, the trial’s Principal Investigator, Dr Sacha Howell of the Christie Hospital, Manchester, UK, said:
“The design of the STEM study, adding the drug to endocrine therapy on which a patient’s cancer was progressing, sets a high bar for SFX-01. In light of this, these interim results are highly encouraging. Objective responses indicate activity in this setting, and disease stabilisation for 6-12+ months represents clinically meaningful prolongation of response. SFX-01 is generally well tolerated and the results together, should they look similar in the final analysis, suggest further investigation of SFX-01 in advanced breast cancer is warranted.”
Prof Francois Duhoux, of University Clinics St-Luc, Brussels, and the Belgium national coordinator for the trial, said:
“Six of these first 20 patients came through my clinic and I can confirm the excellent safety profile of SFX-01. These patients have metastatic disease and have demonstrated progression on their endocrine therapy prior to coming on the trial, and, instead of switching to an alternative regimen, they continued their endocrine therapy with the addition of SFX-01. While we must of course wait for the results of the entire study before making any definitive judgment, in this context I think that the initial results pertaining to efficacy are highly encouraging.”
Dr Steve Franklin, Evgen’s CEO, commented:
“This initial data is promising. We can add that two of the first 20 patients in the trial have been on SFX-01 for approximately one year – six months in the trial and a further six months in the compassionate use programme. One of these patients remains on the drug to this day. This extended treatment makes an important contribution to our understanding of the product’s longer-term tolerability and safety and highlights its potential patient benefit.”