Staff Writer

Keryx Biopharmaceuticals Inc. reported that its investigational perifosine-based treatment for advanced metastatic colon cancer doubled survival and showed other statistically significant advantage over capecitabine (Xeloda).

Perifosine also outperformed capecitabine in other key areas: time to progression and the percentage of patients achieving stable disease lasting 12 or more weeks or better, Keryx said, reporting the results at the American Society of Clinical Oncology (ASCO) Gastrointestinal Cancers Symposium in Orlando, Fla.

In addition, the overall response rate was 20 percent for the group treated with a combination of perifosine plus capecitabine, vs. 7 percent in the capecitabine-treated arm. Data from the Phase II colon cancer study of perifosine already were reported last year before the survival data had matured. (See BioWorld Today, June 2, 2009.)

But the updated results presented at ASCO showed a statistically significant survival advantage.

And for the first time, the company reported data for a sicker group of patients, those who were refractory to the chemotherapy regimen 5-fluorouracil (5-FU). Differences between the group treated with the perifosine-based regimen and capecitabine also were seen in the 5-FU refractory subpopulation. "To see an advantage in a patient population that sick or that advanced is quite unique," CEO Ron Bentsur told BioWorld Today.

All of the study patients (with the exception of one capecitabine-arm patient) had been treated with the chemo drugs FOLFIRI and/or FOLFOX, almost 80 percent treated with Avastin, and half treated with an EGFR antibody. Currently, no drugs are approved for metastatic colon cancer patients who have stopped responding to all of the available treatments.

New York-based Keryx plans to meet with the FDA in the next three months to come up with a design for a Phase III colon cancer study of perifosine. Keryx certainly has the cash to run that trial, if it so chooses.

"We don't feel that we have to do any fundraising right now," Bentsur said. With the cash it has on hand plus an expected milestone payment from another product, he said that the company should have sufficient funds to run the trial. Keryx expects to receive a milestone payment from Japan Tobacco Inc. and Torii Pharmaceutical Co. Ltd. for the start of a Phase III study of Zerenex in Japan, which could occur in the second half of the year. At the end of September 2009, Keryx had cash, cash equivalents, interest receivable and investment securities of $41 million.

The company already is running two Phase III trials, including one evaluating perifosine in patients with multiple myeloma. That trial is expected to complete enrollment by mid-2011, and data are expected by year-end 2011. The FDA has granted fast-track status for the Phase III perifosine program, allowing Keryx to submit a new drug application on a rolling basis, and an expedited review.

Its other Phase III study involves phosphate binder Zerenex is being evaluated as a possible treatment of elevated phosphate levels (hyperphosphatemia) in patients with end-stage renal disease. That study consists of a short-term study that is expected to begin by the end of the first quarter and a long-term study that is expected to begin in the middle of the year.

Keryx has reached an agreement with the FDA on the design of each of its Phase III programs under special protocol assessments. (See BioWorld Today, Jan. 6, 2010.)

Shares of Keryx (NASDAQ:KERX) rose 10 cents to close at $2.84 Monday.

In other news from the ASCO GI Symposium:

• Immunomedics Inc., of Morris Plains, N.J., reported that a pancreatic cancer-specific radio-labeled antibody combined with low-dose gemcitabine chemotherapy showed evidence of tumor shrinkage and pain relief in an ongoing Phase I/II study. Some 68 percent of evaluable patients showed evidence of tumor shrinkage or stable disease, with one-third of those being assessed by computed tomography as partial responses (i.e., responses showing decreases in tumor size of more than 30 percent and in the absence of new lesions), the company said.

• Merck Serono, a division of Merck KGaA, of Darmstadt, Germany, reported that Erbitux (cetuximab) provided an improvement in overall survival when added to the standard first-line FOLFIRI chemotherapy regimen for metastatic colorectal cancer patients with KRAS wild-type tumors in the CRYSTAL study (Cetuximab combined with iRinotecan in first line therapY for metaSTatic colorectAL cancer). In addition, the final results from the study included an analysis of the predictive value of BRAF status on Erbitux efficacy, indicating that patients with KRAS wild-type tumors bearing a BRAF mutation also benefit from Erbitux treatment. KRAS, the company said, remains the only validated, clinically predictive marker of responsiveness to that drug.