IDM Pharma Inc. follow-up survival data from a late-stage clinical trial showed that adding the company's L-MTP-PE drug to chemotherapy helped raise survival rates for children with osteosarcoma, a rare and often fatal bone tumor

IDM Pharma Inc. follow-up survival data from a late-stage clinical trial was part of a National Cancer Institute-funded cooperative group study conducted by the Children's Oncology Group. Shares fell 6 cents to close at $1.39, but gained 21 cents, or 15 percent, to $1.60 in aftermarket trading.

About 3 percent of all childhood cancers are osteosarcoma, with fewer than 1,000 new cases diagnosed in the U.S. each year. It most commonly affects children and young adults experiencing their adolescent growth spurt. According to the Children's Oncology Group, the survival of children with osteosarcoma has remained at 60-65 percent since the mid-1980s.

The standard treatment for osteosarcoma is tumor removal with combination chemotherapy before and after surgery.

The study evaluated the effects of adding L-MTP-PE to chemotherapy in patients with resectable osteosarcoma without spreading disease. In the analyses by the COG investigators of 672 patients, 67 percent of those patients receiving chemotherapy and L-MTP-PE had event-free survival after six years, compared with 61 percent of patients treated solely with chemotherapy. Overall survival after six years was 78 percent for patients receiving the combined treatment and 70 percent for those who underwent chemo only.

L-MTP-PE was granted orphan drug status in the United States in 2001. IDM Pharma submitted a new drug application for L-MTP-PE to the Food and Drug Administration in October 2006, but an FDA committee voted in May 2007 that data from the late-stage study didn't show substantial effectiveness.

In July 2007, following a meeting with the FDA, the company agreed to collect, analyze and submit additional data for L-MTP-PE to the FDA by the first quarter of 2008. The FDA requested data from additional clinical trials to demonstrate the benefit of L-MTP-PE, as well as information or clarification on other items.