The trial, currently ongoing at The University of Texas MD Anderson Center, is investigating Oncoprex in combination with the tyrosine kinase inhibitor (TKI) erlotinib (Tarceva) in the treatment of up to 57 patients with late stage NSCLC, with and without epidermal growth factor receptor (EGFR) mutations and have failed at least two drug regimens.
Out of the nine currently evaluable trial participants, the combination treatment has so far led to:
An overall disease control rate (stable disease, partial response or complete response) of 78%
- A durable complete response in one patient with multiple lesions
- Regression of lesions by 24% in one EGFR-negative patient
- Regression of 30% in one lesion and of 18% across all lesions in one EGFR-negative patient
- Stable disease, tumour regression and decreased metabolic activity in multiple tumours in one EGFR-positive, T970M mutation-negative patient
- Stable disease in three additional patients
Oncoprex also showed a favourable safety profile in all patients, similar to that presented in phase 1 trials.
“These interim data suggest that this targeted therapy may provide a viable treatment option for late stage NSCLC patients, with or without EGFR mutations, whose disease has progressed following currently available treatments,” said Rodney Varner, CEO of Genprex. “If these positive interim results are sustained in either of these populations through the trial’s conclusion, we plan to ask the FDA to grant accelerated approval for this therapy.”
Currently, those with late stage NSCLC are given systemic chemotherapy as a first-line treatment. Those NSCLC patients with an EGFR mutation can be treated with TKIs such as erlotinib, however these types of tumours tend to develop resistance to TKIs within two years.
Next generation TKIs are being developed that target resistant, EGFR-positive tumours that carry a mutation in a gene called T790M, although these set of genetic circumstances are only found in around 50% of patients.
A targeted treatment for those EGFR-positive patients without a T790M mutation does not currently exist meaning these patients have a very poor prognosis.
If Oncoprex maintains these positive results, it could represent a treatment option for this subset of patients when combined with erlotinib.