Highlights from ASCO

The 45th Annual Meeting of the American Society of Clinical Oncology (ASCO) was held from 29th May to 2nd June, in Orlando, FL. Whilst a previous editorial published in Cancer Drug News (see Issue No. 364 - "Looking ahead to ASCO") noted that the 4,000 study abstracts for this year's meeting had drawn a mainly disappointing response, there were numerous encouraging results reported. Of particular note were positive Phase III data with Roche's Herceptin (trastuzumab) in aggressive gastric cancer (GC), Phase II results with AstraZeneca's olaparib in breast (BC) and ovarian cancer (OC), and final results from a Phase II trial of OncoGenex Pharmaceuticals' OGX-011 in prostate cancer (PCA).

Specifically, trastuzumab showed unprecedented survival in aggressive GC. Data from the international, Phase III ToGA study demonstrated that adding the drug to standard chemotherapy increases average survival by 26 per cent in patients with HER2-positive advanced and inoperable GC compared to chemotherapy alone. This combination is also particularly beneficial to GC patients whose tumours express higher levels of HER2, increasing their median survival to 16 months. Trastuzumab is already well established as the foundation of care for patients with HER2-positive BC and now, based on the ToGA results, Roche is to seek regulatory approvals for its use in HER2-positive advanced GC.

Separately, olaparib showed potential to make significant impact on outcomes of patients with BRCA-deficient BC and OC. Phase II data for the novel, oral poly (ADP-ribose) polymerase (PARP) inhibitor demonstrated that it is effective and well tolerated in women carrying the BRCA1 or BRCA2 gene mutation with BC or advanced OC. PARP inhibition is being explored as a new therapeutic approach in cancers with impaired DNA repair pathways, one example of which is cancers with BRCA deficiency. Indeed, both studies were selected for inclusion in the 'Best of ASCO' scientific programme.

Finally, it was reported that OGX-011 provides survival benefit to PCA patients. OncoGenex presented final results from a Phase II trial, with analyses indicating a survival benefit in PCA patients treated with the compound in combination with docetaxel compared to docetaxel alone. Patients treated with OGX-011 had a rate of death 51 per cent lower than those treated with docetaxel alone. Scott Cormack, President and CEO of OncoGenex, noted that a 39 per cent reduction in death, consistent with the previously-disclosed preliminary analysis, would be a significant advancement for treatment in this patient population, adding: "the multivariate analysis shows an even greater reduction in death rate than our preliminary data and increases our confidence that we are seeing a real and meaningful survival benefit for patients treated with OGX-011...these data clearly justify advancing to Phase III development, and we expect these data will be key in our partnering discussions for future clinical development and potential commercialisation."

Alice Rossiter - Cancer Drug News Editor

Looking ahead to ASCO

As the 45th Annual Meeting of the American Society of Clinical Oncology (ASCO) looms, there is just time to look at the data and presentations that will be making the biggest impact. The 4,000 study abstracts for this years Meeting, to be held from 29th May to 2nd June, in Orlando, FL, have now been published, and have drawn a mainly disappointing response. However, there are some biotech companies that will be worth keeping an eye on.

One such company with positive results to present is OncoGenex Pharmaceuticals, whose investigational prostate cancer (PCA) drug, OGX-011, has produced promising Phase II results. Some analysts have commented that the data could be significantly better than Dendreon’s Provenge (sipuleucel-T). At the time results were submitted to ASCO, the preliminary median overall survival in patients with advanced PCA who were treated with OGX-011 plus docetaxel was 27.5 months compared to 16.9 months for patients treated with docetaxel alone. Final survival data as of April for this trial will be presented during the Meeting.

Another company to report encouraging results will be Exelixis, from a Phase II study of XL184 in patients with progressive glioblastoma multiforme. The drug is being co-developed with Bristol-Myers Squibb. In the trial, XL184 was shown to shrink brain tumours in some patients, according to interim results. At four weeks, 26 patients have been assessed. Ten of them (38 per cent) had tumour shrinkage of at least 50 per cent, including one patient who had a 100 per cent reduction in tumour size. Nine patients had tumour measurement changes ranging from 24 to -49 per cent and seven had at least a 25 per cent increase in tumour burden. Of 17 patients who had not received prior anti-angiogenic treatment, nine had at least a 50 per cent reduction in tumour burden.

OSI Pharmaceuticals will also create a lot of attention at the Meeting. The company will present data from two Phase III studies looking at the use of its drug Tarceva (erlotinib) as front-line maintenance therapy in patients with non-small cell lung cancer. OSI hopes that the data from the two studies, called SATURN and ATLAS (AVF3671g), will convince physicians to use the drug, which is co-marketed with Roche, more in the maintenance setting. However, results showed only a small gain over placebo in the time before disease progressed for certain lung cancer patients, leaving many onlookers less than impressed with the data.

Apart from these presentations, there seems little to get excited about. Roche will present data on the use of adjuvant Avastin (bevacizumab) in colon cancer, but the company has already disclosed the study's failure to produce a significant survival benefit. Results of that trial, known as C08, along with around 30 late-breaking studies will be unveiled at the Meeting, which will hopefully hold more surprises than the published abstracts.

Matthew Dennis - Editor, Cancer Drug News