A single Phase 3 trial needed for 505(b)(2) approval of a combination drug

Alchemia Ltd., an Australian pharmaceutical company, announced that it had gained agreement with FDA that a single Phase 3 trial would suffice for approval of its chemotherapeutic drug HA-irinotecan (a new drug containing irinotecan (Pfizer’s Camptosar^®) formulated with hyaluronic acid (HA).   Alchemia has conducted phase 1 and 2 studies outside the U.S.  It presented the results of these trials to FDA in a pre-IND meeting.

Currently Camptosar is combined with Erbitux^®(cetuximab) to treat colorectal cancer.  According to the press release, the single phase 3 study “will enroll around 400 patients with metastatic colorectal cancer who have failed previous treatments. Half of the patients will receive Alchemia’s HA-irinotecan in combination with Erbitux^®whilst the control arm will receive unmodified irinotecan plus Erbitux^®. The primary endpoint will be progression-free survival (PFS). The study will be double-blinded such that the patient and the clinician will not know which treatment is being administered.”

A learning from this news is that a Sponsor does not need to conduct all studies in the U.S.  However, the foreign-based studies must meet U.S. regulatory needs.  We are a bit surprised that Alchemia advanced to Phase 2 without the pre-IND meeting.   Some sponsors may feel this is an unneeded risk.  Camargo has seen numerous cases where the foreign-based trials do not meet FDA requirements – the sponsor has to do the trials over.