Array BioPharma Inc.'s stock gained over 17% after a drug combination of two of its medicines, Mektovi and Braftovi, with Eli Lilly and Co.'s Erbitux was shown to reduce tumor size and increase survival duration in certain cancer patients.

Array BioPharma stocks were trading up 17.08% as of 11:17 a.m. ET on May 21 to $24.54.

Boulder, Colo.-based Array was studying the regimen in a late-stage trial called Beacon CRC which enrolled previously treated patients with BRAF-mutant colorectal cancer that starts in the colon and spreads to other parts of the body.

Based on an interim analysis, a little over 26% of patients receiving the drug combination saw a reduction in their tumor, compared to 1.9% of those that received a combination of the Eli Lilly drug and chemotherapy. Those on the triple-drug regimen survived longer: nine months versus 5.4 months for those receiving Erbitux, or cetuximab, plus chemotherapy.

Array plans to submit a marketing approval for the drugs in this indication in the second half of the year. Array said the drug combination has the potential to be the first chemotherapy-free, targeted regimen for metastatic colorectal cancer patients.

Worldwide, colorectal cancer is the third most common type of cancer in men and the second most common in women, with approximately 1.4 million new diagnoses in 2012.

The U.S. Food and Drug Administration has already approved a combination of Mektovi and Braftovi to treat skin cancer patients with the V600E or V600K mutation in their BRAF gene and whose cancer cannot be removed completely through surgery or has spread to other parts of the body.