Amgen (NASDAQ:AMGN) finds itself at the bottom of the colorectal-cancer ladder these days. And that's not a great place to be -- especially when you consider what lies at the end of the colon.

The company's cancer treatment Vectibix managed a paltry $153 million in sales last year, because the drug is approved only as a treatment for patients who fail three different chemotherapy regimens, including sanofi-aventis' (NYSE:SNY) Eloxatin and Pfizer's (NYSE:PFE) Camptosar. By contrast, Bristol-Myers Squibb's (NYSE:BMY) and Eli Lilly's (NYSE:LLY) competing drug, Erbitux, is approved for use after colorectal cancer patients have failed Camptosar.

Amgen still hopes to ascend this ladder, though. Clinical trial data released Monday night showed that Vectibix was able to extend the progression of the cancer treatment in combination with FOLFIRI, a chemotherapy combination that contains Camptosar. Vectibix extended overall survival compared with FOLFIRI treatment alone, although the benefit wasn't statistically significant. Even better, though, is that Vectibix significantly improved progression-free survival. That part should be enough to get the label changed to indicate that it's approved for use earlier in disease progression.

Earlier this month, Amgen also showed that Vectibix extended progression-free survival in combination with the first-line treatment containing Eloxatin. Taken together, the results should help Vectibix better compete for patients with colorectal cancer.

Amgen modified the clinical-trial designs to include analyzing subclasses of patients depending on their K-ras designation, after retrospective analysis showed that Vectibix and Erbitux worked only on tumors that have mutation-free K-ras genes. Some will also argue that this new data, which supports the conclusion of the retrospective studies, gives Vectibix ammunition over Erbitux because prospective trials are much better than retrospective ones that look at data after the fact. But I think doctors are pretty convinced that the K-ras status plays an important role in whether patients respond to both Vectibix and Erbitux, so I doubt that this news alone will give Vectibix much of an advantage.

Even if the K-ras data doesn't help, the fact that Vectibix works on patients earlier in the disease progression should help sales. Combined with Prolia's mostly positive advisory panel for last week, Amgen looks like it's poised to pop.