* T-DM1 boosts PFS with fewer side effects in Phase II study
* Breast cancer drug could help protect Herceptin franchise
* T-DM1 developed with ImmunoGen; Roche stock up 0.6 pct
ZURICH, April 7 (Reuters) - Breast cancer patients given Roche’s ROG.VX experimental drug T-DM1 lived longer with their disease under control and had fewer side effects than those on standard treatment of Herceptin plus chemotherapy, a mid-stage trial showed.
The news from the Phase II clinical study represents a boost for Roche’s breast cancer franchise, since T-DM1 — a new kind of “armed antibody” that can carry a cell-killing payload into cancer cells — is a key follow-up product to Herceptin.
Thursday’s results showing a significant improvement in progression-free survival, or PFS, go beyond what researchers reported last October, when T-DM1 showed encouraging results in tumour shrinkage.
The study, which looked at previously untreated patients, is also likely to bolster ImmunoGen Inc (IMGN.O), which is developing the drug with Roche. [ID:nLDE6971Y3]
“Although results will need to be replicated in ongoing larger trials, the news is clearly an incremental positive in Roche’s efforts to protect its Herceptin franchise from biosimilar competition, which could materialise from 2014/2015 in Europe and 2019 in the United States,” Deutsche Bank analyst Tim Race said.
Helvea analyst Karl-Heinz Koch said he expected the combined franchise of Herceptin and T-DM1 to remain stable despite the likely emergence of biologic competition to Herceptin from 2014.
T-DM1 combines trastuzumab, the active ingredient in Herceptin, with a potent chemotherapy agent. The fact that it delivers its toxic payload directly into cells is thought to be key to why it causes fewer side effects.
Roche is the world’s largest maker of cancer drugs.
At 1045 GMT, Roche stock was trading 0.6 percent higher, in line with the European healthcare index .SXDP. (Reporting by Katie Reid; editing by Ben Hirschler)