Oct 28 (Reuters) - Merck ( MRK ) and Eisai's ( ESALF )

experimental combination treatment helped extend the time

certain patients with advanced kidney cell cancer lived without

their disease progressing, in a late-stage study, the drugmakers

said on Tuesday.

However, the combination of Merck's ( MRK ) Welireg and Eisai's ( ESALF )

Lenvima failed to meet the second main goal of showing

statistical significance in extending overall survival, which

measures the length of time patients live after diagnosis or

start of treatment.

The companies plan to test overall survival at a subsequent

analysis.

The combination was tested in patients whose cancer has

progressed on or after treatment with immunotherapy.