New Pfizer drug may add to mix in lung cancer war

* PF-299 shows promise in small mid-stage study

* 85 pct of mutated EGFR patients progression-free at 9 mths

MILAN, Oct 11 (Reuters) - A drug being developed by Pfizer PFE.N known as PF-299 has shown an ability to prevent lung cancer getting worse when given as a first-line treatment to patients with advanced disease in a small study.

Nearly 85 percent of patients whose cancers had mutated versions of the so-called EGFR gene were progression-free for at least nine months, according to preliminary results from the mid-stage Phase II study presented on Monday.

Existing cancer pills like AstraZeneca's AZN.L Iressa and Roche's ROG.VX Tarceva are already known to be effective against cancer in patients with a mutation activating the epidermal growth factor receptor (EGFR).

But PF-299 has a broader effect and may add to the arsenal of compounds against non-small cell lung cancer -- the most common form of the disease -- if later stage trials are successful.

So far the study has looked at only 74 patients but Dr. Tony Mok from the Chinese University of Hong Kong said the findings were encouraging, since they supported the idea that newer drugs targeting multiple points on the receptor pathway might have an advantage.

After nine months of treatment 57.1 percent of patients overall and 84.7 percent of those patients with EGFR mutations remained progression-free, he told the European Society for Medical Oncology (ESMO) congress.

EGFR mutations are most commonly found in non-smokers and Asian populations.

Dr. Enriqueta Felip, from Vall d’Hebron Hospital in Barcelona, who was not involved in the research, said the findings were encouraging.

Overall survival could not be estimated because so few patients have died in the study so far.

Mace Rothenberg, head of clinical development and medical affairs for Pfizer’s oncology unit, told Reuters that PF-299 could represent another step in personalising care in lung cancer -- something which has been emphasised at ESMO with results from other clinical studies. [ID:nLDE69805O]

“It’s an important next step in first-line medicine in really trying to match the right therapy to the right patient,” Rothenberg said.

Pfizer is working on a more advanced lung cancer treatment called crizotinib, which it plans to file for regulatory approval next year. Results presented in June showed crizotinib shrank lung cancer tumours in more than half of treated patients and nearly all showed some benefit. [ID:nN05159626]

Crizotinib works in a different way, by blocking a genetic mutation that occurs when two genes fuse together to form a gene called EML4-ALK, which causes cancer. (Additional reporting by with Bill Berkrot in New York; Editing by Greg Mahlich)