Astex Pharma shares down after company drops amuvatinib development

US drug developer Astex Pharmaceuticals (Nasdaq: ASTX) saw its shares fall 8.1% to $3.05 by close last Friday, after the company revealed that clinical development of amuvatinib (MP-470) has been discontinued.

Amuvatinib was being investigated in the Phase II ESCAPE (TrEatment of Small Cell lung cancer with Amuvatinib in combination with Platinum Etoposide) study. The study used a Simon 2-stage design with the primary objective in stage 1 of excluding the statistical probability with 90% confidence that the drug has less than 10% response rate in platinum refractory small cell lung cancer (SCLC) patients. Response evaluation by RECIST criteria showed 2 partial responses in the 21 evaluable patients of stage 1 (9.5% Response Rate). No new safety issues were identified, and biological markers studies are ongoing. There were several patients with prolonged stable disease. The results will be presented in a future scientific meeting.

"This clinical proof of concept (cPOC) amuvatinib trial was designed in two parts to define clinical activity and confirm clinical benefit and safety in combination with chemotherapy," said James Manuso, chairman and chief executive of Astex, adding: "We have decided to end the clinical development of amuvatinib despite the favorable safety and preliminary clinical activity we observed in the first stage of this Phase II trial and in the earlier Phase Ib trial in combination platinum-etoposide based chemotherapy.”