UPDATE 1-Regeneron to not submit ovarian cancer drug data

* Regeneron, Sanofi not to submit mid-stage data

* Regeneron inks 2 royalty agreements with Novartis

June 11 (Reuters) - Regeneron Pharmaceuticals (REGN.O) and Sanofi-Aventis (SASY.PA) said they will not submit data from the mid-stage study of their experimental drug, aflibercept, to treat ovarian cancer, citing difficulty in assessing the overall clinical benefit from the treatment.

Regeneron said it would now focus its efforts on completing the current late-stage program which combines aflibercept with standard chemotherapy regimens for the treatment of earlier stage metastatic colorectal, non-small cell lung, pancreatic, and prostate cancers

The mid-stage study, however, showed a statistically significant improvement in the main goal of increasing mean time to first repeat paracentesis, or removal of fluid from the abdominal cavity, compared with a dummy drug.

But given the small number of patients enrolled in the study and the fragile health status of the advanced ovarian cancer patients, it was difficult to definitively assess the overall clinical benefit that might be derived from treatment, the company said.

Separately, Regeneron said it entered into two royalty agreements with Novartis Pharma AG that replace a previous collaboration and license deal.

Regeneron is now entitled to receive royalties on worldwide sales of Novartis' arthritis drug, canakinumab, and a second-generation interleukin-1 Trap.

The agreements replace a 2003 deal under which Regeneron had the right to opt in to the development and commercialization of Novartis' interleukin-1 antibody and Novartis had the right to opt in to the development and commercialization of Regeneron's second-generation interleukin-1 Trap.

Shares of Regeneron were down 10 cents at $16.25 Thursday on Nasdaq.

For the alerts double-click [ID:nWNAB8835] [ID:nWLA6437]. (Reporting by Anand Basu in Bangalore; Editing by Aradhana Aravindan)