Halozyme Therapeutics Inc. (HALO) said its drug candidate, PEGPH20, used in combination with Celgene Inc.'s (CELG) Abraxane and Eli Lilly & Co.’s (LLY) gemcitabine, did well in a Phase 2 trial to treat stage IV pancreatic cancer.

The results from mid-stage trial which used the combination therapy demonstrated statistically significant benefits without the cancer getting worse in pancreatic patients with high levels of hyaluronan (HA).

HA is a sequence of naturally occurring sugars which are found on human tissues. These sugar chains can accumulate around certain cancer cells and can lead to contraction of the blood vessels and obstruct other treatments and medicines. PEGPH20 is based on an enzyme and it works by targeting and retarding the HA. (For more, see How Halozyme Uses Enzymes to Deliver Drugs?)

Results of the mid-stage trials indicated a 91% improvement in median progression-free survival (PFS). PFS is the length of time during and after the treatment of a disease, such as cancer, that a patient lives with the disease but it does not get worse. In Halozyme’s trials, between 35 and 40% of the patients have elevated HA levels.

While the recent success will complement a separate Phase 3 pancreatic cancer clinical trial ongoing at more than 160 sites globally, the drug has had its ups and downs in the past. Two years ago, there were concerns raised about drug use linked to high risk of blood clots, which resulted in a trial halt. The trial resumed when it was redesigned to exclude patients having high risk of blood clots.

Pancreatic cancer is the third-leading cause of cancer-related deaths in the US, which killed around 42,000 Americans in 2016. Each year, more than 65,000 individuals in the U.S. and in the top five European nations are diagnosed with advanced cases of the disease.

Halozyme's PEGPH20 drug is also being studied as a combination therapy with Merck & Co Inc's (MRK) Keytruda for treating gastric cancer and lung cancer. It is also being assessed for treating breast cancer in combination with Eisai Co Ltd's Halaven.

Following the update, Halozyme’s share price zoomed around 18%, to close at $12.61 per share on Thursday. (See also: AbbVie Ends Halozyme Development Deal.)

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