UPDATED: ASCO abstracts reveal added appeal for key cancer drug prospects

The avalanche of ASCO abstracts last night triggered a flurry of news reports about the most notable new data on experimental therapies to be revealed ahead of next month's big meeting in Chicago. Here are a few of the highlights:

Aveo Pharmaceuticals

Aveo Pharmaceuticals ($AVEO) is concentrating on new safety data to make the case that tivozanib will be superior to Nexavar in treating kidney cancer. Investigators already announced that patients taking the treatment gained several months of progression-free survival over Nexavar. Now the biotech's abstract reveals that the experimental therapy triggered fewer cases of serious hand-foot syndrome. And the company took the initiative to tout the fact that 35% of Nexavar patients had to interrupt treatment, compared to 18% in the tivozanib crowd. 

"I think the important point is that this is a next-generation VEGF TKI with a cleaner mechanism of action that's focused more intensely on the VEGF receptor, and the VEGF pathway appears to be the most critical pathway in kidney cancer, so if you can more selectively focus on that you can produce equivalent or better efficacy with less toxicity. That's the real potential value of tivozanib," Dr. Michael Atkins, a TIVO-1 study investigator and deputy director of the Georgetown Lombardi Comprehensive Cancer Center in Washington, DC, tells FierceBiotech Executive Editor Ryan McBride.

Pfizer

The data dump included a look at some positive new mid-stage results for Pfizer's ($PFE) dacomitinib, an experimental lung cancer therapy. Three out of four patients in the study demonstrated a response to the treatment, according to Reuters. The preliminary median  progression-free survival rate for patients with advanced cases was an impressive 17 months. Three of the 92 patients in the study had to stop therapy due to toxicity. The drug inhibits a variety of proteins that spur cell division and the pharma giant has a number of studies underway to determine its overall potential.

Array BioPharma

Array BioPharma ($ARRY) reported last fall that its MEK inhibitor selumetinib failed a mid-stage study for a group of lung cancer patients with a KRAS gene mutation. Now we know that the selumetinib/chemo combo delivered a median survival benefit of 9.4 months, compared to 5.2 months for the chemo arm. That was not a statistically significant difference. More than a third of the selumetinib arm demonstrated a response, compared to none in the chemo group.

Also highlighted in the news this morning: An early look at MEK162 showed one confirmed and 6 unconfirmed partial responses, with 9 patients stable among 29 patients with a BRAF mutation, according to Reuters. In a 13-patient NRAS group there were two confirmed partial responses, one unconfirmed and four stable. TheStreet's Adam Feuerstein included a snapshot of the Array data along with details on a variety of the abstracts.

Amgen 

Amgen's ($AMGN) rilotumumab failed a trial last year for gastric cancer. But now the big biotech says it plans to pursue a new study of the drug after finding that a subpopulation of patients with high levels of c-MET experienced a much better response to the drug. C-MET figures into a key protein-protein interaction that can spur cancer metastasis, and the drug prevents the two from combining, reports Bloomberg. The high MET expression population experienced an 11.1 month median survival rate compared to 5.7 months for patients in the placebo arm.