CHICAGO ( TheStreet) -- An ASCO tale of two colon cancer drugs: One very good, that would be Roche's ( RHHBY) Avastin, and one very, very bad, otherwise known as Keryx Pharmaceuticals' ( KERX) perifosine. Let's start with Keryx because everyone likes a smidge of schadenfreude once in awhile. Keryx shares tanked in April on the failure of perifosine to prolong survival of colon cancer patients in a phase III trial, yet the detailed results of the negative study were kept under wraps until today at the American Society of Clinical Oncology annual meeting. Patients in the control arm of the study lived longer than those treated with perifosine. DOH! The details: Median overall survival for patients treated with perifosine and Xeloda was 6.4 months compared to 6.8 months for patients treated with Xeloda and placebo. The hazard ratio was 1.11, which means perifosine actually raised the risk of patients dying faster. Now we understand why Keryx returned rights to perifosine to Canada's Aeterna Zentaris ( AEZS). By doing so, Keryx also gave up on an ongoing phase III study of perifosine in multiple myeloma. When your cancer drug does harm, it's probably a good idea to stop testing it. Question: Why hasn't Aeterna learned the hard lesson about perifosine that Keryx has? Moving to more positive colon cancer drug news: Roche's Avastin combined with chemotherapy is a mainstay therapy in newly diagnosed, or front-line patients, as well as for second-line therapy. New research presented Sunday demonstrates that colon cancer patients benefit most when chemotherapy regimens are switched between first and second line but Avastin is continued uninterrupted. "By simply switching chemotherapy drugs when the cancer progresses and continuing with bevacizumab Avastin , we can make second-line treatment even more powerful," said Dr. Dirk Arnold of the Hubertus Wald Tumor Center in Hamburg, Germany and an investigator in the Avastin study. The phase III study enrolled 820 patients with metastatic colon cancer who were treated with either an oxaliplatin- or irinotecan-based chemotherapy plus Avastin. The patients were followed and when their colon cancer returned, the patients were randomized to receive the opposite chemotherapy plus Avastin or a placebo. When the study was analyzed, treatment with chemotherapy and Avastin as a second-line therapy led to an improvement in overall survival (11.2 months vs. 9.8 months) and progression-free survival (5.7 months vs. 4.1 months) compared to chemo plus placebo.