Biotech Stock Mailbag: Keryx Biopharmaceuticals

BOSTON (TheStreet) -- Let's kick off this week's Biotech Stock Mailbag with a tweet rather than an email.

Via Twitter, @bobbandera asks, "Any opinion on the Keryx Biopharmaceuticals(KERX) data released for its colon cancer drug?"

The Keryx cancer drug in question is perifosine and much of the data presented this week are not new, but first released last May at the American Society of Clinical Oncology (ASCO) annual meeting. Here's what I wrote about the perifosine data last May:

"The data presented on perifosine at ASCO came from a small, randomized phase II study in patients with second- or third-line metastatic colon cancer. Patients treated with a combination of perifosine and the chemotherapy Xeloda reported that it took 28.9 weeks before their tumors started growing again. That's more than double the 11 weeks for patients treated with Xeloda alone.

"Twenty percent of patients in the perifosine arm of the study reported tumor shrinkage compared to 7% for patients in the Xeloda-alone arm. Perifosine patients were also living longer, although survival data is not yet mature."

On Monday, Keryx presented an update to this perifosine trial. Importantly, the now-mature survival data looks strong, with median overall survival of 18 months for the perifosine-Xeloda patients compared to 11 months for the Xeloda-alone patients. The survival benefit was statistically significant in favor of perifosine. The rest of the efficacy data -- response rate and progression-free survival -- remained unchanged from when the data were first presented last May.

These data are certainly encouraging, but as I noted last May, this phase II study was small, with only 38 patients enrolled. And only half the patients in the study received prior treatment with Erbitux or Vectibix, the two colon cancer drugs from the EGFR inhibitor class marketed by Eli Lilly(LLY) and Amgen(AMGN), respectively, that are commonly used in second- and third-line colon cancer patients.