ASCO '12 Abstract Dump: Cancer Stocks in Focus

BOSTON ( TheStreet) -- Investors got their first look at thousands of cancer drug research abstracts released Wednesday night by the American Society of Clinical Oncology (ASCO) in advance of its closely watched annual meeting.

Among the most significant cancer drug data unveiled for the first time Wednesday night came from phase III studies conducted by Aveo Pharmaceuticals ( AVEO) and Exelixis ( EXEL), and randomized phase II studies of drugs discovered by Array BioPharma ( ARRY).

New disclosures of cancer drug data were also made available from Arqule ( ARQL), Ariad Pharmaceuticals ( ARIA), Pharmacyclics ( PCYC), Onyx Pharmaceuticals ( ONXX) and Seattle Genetics ( SGEN), among many others.

The ASCO annual meeting runs June 1-5 and brings together cancer drug researchers from all over the world to discuss and present new clinical data aimed at treating -- and maybe one day curing -- cancer. Wednesday's release of research abstracts -- short, preliminary summaries of efficacy and safety data from cancer drug clinical trials -- serves as a warm-up for the big event next month.

The ASCO abstract release is also a closely watched event for Wall Street because the revelation of new cancer drug data often has a significant effect on biotech and drug stocks. Trading volatility can ramp up significantly for many of the so-called "ASCO stocks" -- particularly small-cap biotech stocks -- in the weeks before the ASCO confab gets started.

While investors were flooded with new cancer drug data Wednesday, ASCO did hold back some of the some important and potentially stock-moving research for a more high-profile release at the meeting itself. Key cancer drug data that remains under wrap include results from a phase III study of Johnson & Johnson's ( JNJ) Zytiga in "pre-chemo" prostate cancer patients; a phase III study of Bayer and Onyx's regorafenib in advanced gastrointestinal stromal tumors; several Roche/Genentech ( RHHBY) studies, including Avastin in ovarian cancer and TDM-1 in breast cancer (partnered with Immunogen ( IMGN)); melanoma data from GlaxoSmithKline's ( GSK) targeted drug dabrefenib; and a new targeted PD-1 immunotherapy from Bristol-Myers Squibb ( BMY).

The following pages summarize new and important cancer drug data released tonight by ASCO from research abstracts for its upcoming annual meeting.

Array BioPharma

What we already know: Last September, Array partner AstraZeneca ( AZN) announced top-line results from a phase II non-small cell lung cancer study of selumetinib, in which the combination of selumetinib plus docetaxel demonstrated a "numerically greater increase" in survival compared to docetaxel alone. Patients in the study had non-small cell lung cancer with a mutation in the KRAS gene, which makes the tumors harder to treat.

What's new in the ASCO abstracts: Median overall survival in the selumetinib/docetaxel arm was 9.4 months compared to 5.2 months for docetaxel alone -- a difference of 4.2 months but not statistically significant. Response rate (37% vs. 0%) and progression-free survival (5.3 months vs. 2.1 months) both favored selumetinib/docetaxel over docetaxel alone with statistical significance. (Abstract No. 7503)

Additional ASCO abstracts of note: Take a look at Abstract No. 8511, which reports on early results of a phase II study investigating MEK162 in patients with cutaneous melanoma harboring one of two genetic mutations: BRAFV600 or NRAS. MEK162 is a drug developed by Array and licensed to Novartis ( NVS). Among 29 BRAF-mutant melanoma patients treated with MEK162, there were 1 confirmed and 6 unconfirmed partial responses and 9 patients with stable disease. Among 13 NRAS mutant patients, there were 2 confirmed and 1 unconfirmed partial responses and 4 patients with stable disease.

Aveo Pharmaceuticals

What we already know: Top-line results from the phase III kidney cancer study of tivozanib were announced in early January with tivozanib demonstrating a progression-free survival of 11.9 months compared to 9.1 months for Onyx's Nexavar. In a subset of treatment-naive patients (70% of patients enrolled in the trial), tivozanib PFS was 12.7 months versus 9.1 months for Nexavar. Both results were statistically significant.

What's new in the ASCO abstract: Nexavar performed better than expected in the study, which narrowed the benefit shown by tivozanib and caused some investors to question the tivozanib's true efficacy. Aveo asserts tivozanib's safety data demonstrates superiority over Nexavar.

In the ASCO abstract (No. 4501) released Wednesday, serious hypertension (grade 3 or higher) was reported in 26% of tivozanib patients compared to 18% of Nexavar patients. Serious hand-foot syndrome was reported in 2% of tivozanib patients versus 17% of Nexavar patients. Reported rates of serious diarrhea, fatigue and neutropenia were similar between tivozanib and Nexavar.

Aveo announced additional safety analyses Wednesday outside what's contained in the ASCO abstract: Rate of dose interruptions due to adverse events was 18% for tivozanib compared to 35% for Nexavar; the rate of dose reductions in the study was 14% for tivozanib compared to 44% for Nexavar.

Seattle Genetics

What we already know: Seattle Genetics is in the early stages of launching Adcetris for two different types of lymphomas -- Hodgkin's lymphoma and anaplastic large cell lymphoma. At ASCO this year, Seattle Genetic will be presenting new data seeking to expand Adcetris' use in lymphoma and non-lymphomas.

What's new in the ASCO abstracts: Abstract No. 8027 reports on a phase II Adcetris "retreatment" trial in which HL and ALCL patients who previously responded to treatment with Adcetris are retreated with the drug when their cancer relapses. Like Roche's Rituxan, which can be used multiple times in the same patients, Seattle Genetics wants to eventually expand the Adcetris label to allow for retreatment. According to interim results in the abstract, objective responses were reported in 13 of 20 (65%) of evaluable patients undergoing Adcetris retreatment. Of 11 patients with pre-existing peripheral neuropathy, 3 (27%) had worsening with retreatment.

Abstract No. 8070 reports on a phase II study of Adcetris in patients with various types of non-Hodgkin lymphoma. Ten patients enrolled in the study to date, with six evaluable for efficacy, according to the abstract. Of those six patients, two attained a complete remission following Adcetris therapy. One of the responding patients was diagnosed with diffuse large B-cell lymphoma.

Adcetris works by attaching itself to receptors on cancer cells that express a protein known as CD30. This protein is common in blood-related cancers but may also be found in solid tumors, which could open a larger commercial opportunity for Adcetris. Abstract No. 3069 reports on a study in which 875 patients -- 95% of whom were diagnosed with solid tumors -- were screened for CD30 expression. The screening found 22 patients (2.5%) who were CD30-positive, including patients with ovarian cancer, melanoma, mesothelioma and triple-negative breast cancer.

Onyx Pharmaceuticals

What we already know: An FDA advisory panel will review Onyx's multiple myeloma drug carfilzomib on June 20. Onyx is seeking approval based on a single-arm phase II study in 266 patients with relapsed or refractory multiple myeloma. The overall response rate to carfilzomib therapy was 22.9% with a median duration of response of 7.8 months.

What's new in the ASCO abstracts: Abstract No. 8035 describes an analysis of carfilzomib response rates in the pivotal phase II based on prior treatment with Takeda's Velcade and Celgene's ( CELG) Thalomid or Revlimid. This analysis is important because it addresses investor concerns that carfilzomib's response rate may not be potent enough in multiple myeloma patients who had depleted all other previous treatment options.

In a subset of 228 patients refractory or intolerant to Velcade and at least one other immunomodulator like Thalomid or Revlimid, the carfilzomib response rate was 20.6% with a median duration of response of 7.4 months. In a smaller subset of 44 patients refractory all approved treatments, carfilzomib's response rate was 20.5% with a median duration of response of 7.8 months, according to the abstract.

Exelixis

What we already know: Exelixis is expected to file for the approval of cabozantinib ("cabo") for the treatment of advanced medullary thyroid cancer later this quarter. More importantly, the company is enrolling prostate cancer patients in two phase III studies of cabozantinib.

What's new in the ASCO abstracts: Abstract No. 5508 reports on results from the phase III study of cabo in medullary thyroid cancer. A 7.2-month benefit in progression-free survival (11.2 months for cabo vs. 4 months for placebo) was previously reported. New data includes response rate (28% for cabo vs. 0% for placebo) and an interim analysis of overall survival yielding no difference between cabo and placebo. The survival analysis was conducted on 44% of planned deaths in the study.

A non-randomized expansion of a previously reported phase II study enrolled 93 patients with advanced prostate cancer patients that had spread to bone, causing pain requiring treatment with painkillers. The patients were treated with 100 mg daily of cabozantinib. Abstract No. 4513 describes interim results: 51 of 85 patients (60%) achieved a partial bone scan response, while 21 of 30 patients (70%) had reduction of measurable disease. The abstract doesn't specify how many patients achieved a true complete or partial tumor response.

Forty-six percent (16 of 33 patients) reported a durable reduction in pain and decreased narcotics use. Of these patients, 27% discontinued narcotics. In 59 patients with measurable circulating cancer cells, 92% had a decrease of 30% or greater and 39% had circulating tumor cell reductions below the level of detection.

Pharmacyclics

What we already know: Pharmacyclics and partner Johnson & Johnson are starting pivotal studies of ibrutinib in patients with relapsed or refractory chronic lymphocytic leukemia (CLL). Last December, the companies presented data from a phase II study of ibrutinib in elderly patients with relapsed/refractory CLL showing response rates of 67-68%.

What's new in the ASCO abstracts: From the same study, an interim analysis from a group of treatment-naive, elderly CLL patients treated with ibrutinib showed an overall response rate of 73%, including 8% complete responses and 65% partial responses. The estimated one-year progression-free survival is 93%. (Abstract No. 6507.)

Abstract No. 6508 reports on interim results from a phase Ib/II study combining ibrutinib with Glaxo's Arzerra in patients with relapsed/refractory CLL. The overall response rate to the combination therapy was 100%, all partial responses.

Ariad Pharmaceuticals

What we already know: Interim results from the ponatinib "PACE" study in chronic myelogenous leukemia were first presented last December. With a median reported 5.6-month follow up, 47% of patients reported a major cytogenic, or cellular, response. In the subgroup of CML patients with the T315I mutation, the major cytogenic response was 65%.

What's new in the ASCO abstract: The response data are little changed from the December update because the ASCO abstract (No. 6053) was submitted in January, reflecting a median 6.6 months of follow up. The overall major cytogenic response for CML patients is 49% (higher than in December.) In the T315I subgroup, the response rate is 62% (lower than in December.)

A significant update of results from the PACE study will be presented at ASCO, with six-month follow-up data on all patients available.

Arqule

What we know already: Top-line data from a phase II study of tivantinib in second-line liver cancer were released in January. Liver cancer patients who progressed after first-line therapy were randomized 2:1 to receive tivantinib or a placebo. The study met its primary endpoint with tivantinib demonstrating a 56% improvement in time to tumor regrowth (time to progression, or TTP) compared to the placebo.

What's new in the ASCO abstract: In the overall patient population, tivantinib-treated patients reported a median time to progression of 1.6 months compared to 1.4 months for placebo patients. The small difference was statistically significant with a p value of 0.04. (Abstract No. 6503)

In a subset of patients who over-expressed c-Met, the molecular target of tivantinib, median TTP was 2.9 months for drug versus 1.5 months for placebo -- a statistically significant benefit. In this same patient subgroup, progression-free survival was 2.4 months for tivantinib compared to 1.5 months for placebo -- statistically significant.

A preliminary overall survival analysis trends in tivantinib's favor but is not yet statistically significant. Placebo patients were allowed to cross over and receive tivantinib when their tumors started to grow again.

Tivantinib dose was reduced mid-study due to reports of low blood cell counts in some patients. This helped reduce the rate of neutropenia from 21% to 6%. The most frequent drug-related serious adverse event was neutropenic sepsis (4.2%).

Other notes: Arqule and partner Daiichi Sankyo are conducting a phase III study of tivantinib in non-small cell lung cancer, with an interim analysis expected in the fourth quarter. A phase II study of tivantinib in colon cancer is also ongoing with results possible by year-end or in early 2013.

Oncothyreon

What we know already: Phase I trials showed the experimental drug PX-866 to be well tolerated with some evidence of anti-cancer activity. Oncothyreon is conducting phase II studies of PX-866 in combination with other drugs in non-small cell lung cancer, glioblastoma, prostate cancer, colon cancer and head-and-neck cancer.

What's new in the ASCO abstracts: Interim results from the PX-866 study in patients with recurrent glioblastoma (brain tumors) are described in Abstract No. 2051. Seventeen patients were enrolled and treated with PX-866, 14 of which are evaluable for response. Twelve patients discontinued the study -- nine due to progressive disease and three due to serious elevations of liver enzymes indicative of liver damage.

--Written by Adam Feuerstein in Boston.

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Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.

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