June 4 (Reuters) - The UK cost-effectiveness watchdog on Thursday recommended AbbVie's "guided missile" cancer therapy, Elahere, for patients with a hard-to-treat form of ‌ovarian cancer.

The drug, Elahere, will be made available to patients under a ‌confidential commercial agreement between AbbVie and the state-run National Health Service, the National Institute for ​Health and Care Excellence (NICE) said.

The decision comes after NICE revised its value appraisal framework as part of a broader UK-U.S. deal last year to secure zero tariffs on British pharmaceutical products and medical technology, in exchange for increased drug spending and ‌changes to its assessment criteria.

The ⁠new framework would widen access to treatments previously rejected on cost grounds.

Critically ill patients whose cancer has stopped responding to ⁠standard chemotherapy will now be able to access Elahere through the NHS. The drug was previously limited to clinical trials, private care, or compassionate use.

NICE said that ​around 270 ​patients would be eligible for the drug ​in the first year, rising ‌to about 420 by year three.

The drug will be funded initially through the Cancer Drugs Fund before moving into routine commissioning, which will be 90 days after the final guidance is issued.

Elahere is an antibody-drug conjugate designed to precisely target cancer cells, while limiting damage to healthy tissue.

It is given once every ‌three weeks and has a more manageable side-effect ​profile than chemotherapy, NICE said.

"This recommendation is ​the first in over 20 years ​to offer those diagnosed with ovarian cancer an additional choice ‌at a critical stage," said Victoria ​Clare, CEO of ​Ovacome, a UK-based ovarian cancer support charity.

In a late-stage study of 453 patients, the drug extended survival to an average of 16.9 months and ​delayed disease progression to ‌5.6 months versus 13.3 months of survival extension and nearly four ​months of progression delay seen with chemotherapy.

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(Reporting by Mariam ​Sunny in Bengaluru; Editing by Shinjini Ganguli)