A Bristol-Myers Squibb compound hailed by analysts for its commercial prospects, and a Johnson & Johnson drug that may work in earlier lines of therapy are among the cancer agents drawing attention in the run-up to the year’s most important oncology meeting. 

The BMS cancer agent, which goes by the codename BMS-936558, showed potency and durability in treating advanced tumors of the lung, skin and kidneys, according to abstracts of the full Phase I/II studies released ahead of the American Society of Clinical Oncology (ASCO) meeting. When compared to marketed therapies Tarceva, Yervoy and Nexavar—therapies already marketed for those cancers—response rates were superior regardless of the indication.

A monoclonal antibody, BMS-936558 belongs to a class called anti-PD-1 that is designed to harness the body’s immune system to fight cancer. Based on data revealed in the ASCO abstracts, analysts are enthusiastic.

“BMY’s anti-PD-1 [is] looking like the better, stronger Yervoy,” wrote Barclay’s analyst Tony Butler in an investor note. In treated metastatic melanoma patients, its response rate of 20-41% appears higher than the 11% response rate seen with BMS’s own Yervoy in early studies, Butler pointed out.

Lung cancer could be the most lucrative of the three tumor types, analysts say, because there is a bigger pool of patients, and because evidence suggests the drug may be used earlier in treatment, introducing the possibility of longer treatment duration.

The response rate seen in refractory non-small cell lung cancer patients, 19-28%, easily bested the 8-11% rate seen with existing NSCLC therapies—Roche’s Tarceva, Sanofi’s Taxotere and Sanofi’s Alimta. The agent produced a response rate of about 31% in patients with metastatic renal cancer, compared to 11% and 2% seen in early studies of Bayer’s Nexavar and Novartis’ Afinitor, respectively.

“BMY is advancing all three indications into Phase III, and we estimate a peak potential of up to $2B should all three indications deliver,” wrote Butler.

Biomarker data could further enhance the drug’s appeal. “We believe anti-PD1 COULD be the most exciting clinical and commercial opportunity in oncology since Avastin,” wrote Leerink Swann analyst Howard Liang in an investor note. Among his reasons are the potential for enhanced patient selection via biomarkers and use of anti-PD-1 as a platform for immuno-oncology, meaning it could be married to targeted therapies like Tarceva or Pfizer’s Xalkori to further enhance response rates.

While it’s too early to determine whether either of those possibilities will pan out, Liang predicted anti-PD-1 could reach $2 billion in sales by 2020, implying a 50% chance of success on peak potential sales of $4 billion. That’s somewhat less than the $6.5 billion in global revenue earned by Roche’s top-selling Avastin in 2010, the year before the FDA withdrew its approval in metastatic beast cancer (it remains on the market for advanced colon, lung, kidney and brain cancers).

Another blockbuster would help BMS replace revenue losses from older brands going off patent. The drugmaker is regarded as having the most productive pipeline these days. Phase II hepatitis C treatment daclatasvir looks promising, and the company is waiting for the FDA to approve anticoagulant Eliquis (apixaban), which BMS and Pfizer plan to launch as a replacement for warfarin. But BMS lost a mega blockbuster, antiplatelet brand Plavix, to the patent cliff earlier this month, while blood pressure pull Avapro lost exclusivity in March. First-quarter revenues rose 5% vs. the first quarter of 2011.

BMS said it will release more data from a 290-patient study on ‘558, as well as for a related drug, BMS-936559, in advanced NSCLC, metastatic melanoma and renal cell cancer in five oral presentations—four on Saturday, June 2, and one on Monday, June 4—and in an ASCO press briefing tomorrow.

Data set for release at ASCO could also impact J&J, whose Zytiga prostate cancer med has already posed a threat to Dendreon’s Provenge. Results of a study testing Zytiga in patients prior to their use of chemo “support further evaluation” in the neoadjuvant/adjuvant setting, according to the ASCO abstract. Additional data from the study (COU-AA-302) are scheduled to be presented Saturday.

“To an extent, consensus is anticipating positive Zytiga ‘302′ results, though there seems to be a good deal of uncertainty as to what specifically should be expected,” wrote Credit Suisse analyst Lee Kalowski in an investor note.

On overall survival, Kalowski expects the data to show at least 13 months of pre-chemo duration, possibly closer to 16. That would have implications for biotech firm Medivation, as well, which is testing its own investigational agent, MDV3100, in patients with prostate cancer prior to chemo. Called PREVAIL, the trial is expected to yield data in 2013. If the ‘302 and PREVAIL studies show the drugs have uses in earlier stages of the disease, both could squeeze Provenge’s outlook in prostate cancer, noted Butler.

In addition, Novartis is getting set to release data on two marketed drugs from its oncology portfolio: Afinitor in breast cancer and Tasigna, both in patients with chronic Philadelphia chromosome-positive chronic myeloid leukemia who were switched from Novartis’ older drug Gleevec, and in the newly diagnosed.

Among biotech firms expecting big reveals are Ariad Pharmaceuticals, preparing to release more follow-up data on pipeline candidate ponatinib in leukemia, and Array Pharmaceuticals, whose Phase II drug selumetinib is moving into Phase III on the back of compelling results seen in NSCLC. Selumetinib is being co-developed with AstraZeneca.