US-based Spectrum Pharmaceuticals has begun a Phase II clinical trial of its new pan-HER inhibitor, Poziotinib, for patients with HER2-positive metastatic breast cancer.
The open-label trial will involve around 70 patients who have failed at least two prior HER2-directed therapies.
The company noted that Poziotinib has shown a 60% response rate in Phase I patients with breast cancer who had previously failed multiple lines of treatment, including the HER2-directed therapies.
Poziotinib irreversibly blocks signalling through the epidermal growth factor receptor (EGFR, HER) family of tyrosine-kinase receptors, including HER1, HER2, and HER4.
It also blocks HER receptor mutations, which inhibits the proliferation of tumour cells that overexpress these receptors.
Spectrum Pharmaceuticals chairman and chief executive officer Rajesh Shrotriya said: "We believe Poziotinib has the potential to be the best-in-class pan-HER inhibitor.
"The US Phase II trial was designed on learnings from Hanmi's Phase I studies, as well as the ongoing Phase II breast cancer trial in Korea.
"The target market for HER2-positive agents is large, and we are encouraged by early data showing that Poziotinib could potentially be another treatment option for patients."
It is reported that mutations or overexpression / amplification of EGFR family receptors have been associated with a number of different cancers, including non-small cell lung cancer (NSCLC), breast cancer and gastric cancer.
At present, poziotinib is being evaluated by Hanmi in several mid-stage trials in different solid tumour indications, including HER2-positive breast cancer.