Unsurprisingly, Roche, the world’s largest cancer company, has been presenting data on a number of its products at the American Society of Clinical Oncology meeting in Chicago this week as it seeks to expand market share for some of its blockbuster treatments.

Avastin (bevacizumab) has figured a great deal, most notably regarding its potential as a treatment for kidney cancer. Adding Avastin to interferon offers patients with advanced renal cell cancer the chance to live twice as long without their disease advancing compared with interferon alone, according to data from the Phase III AVOREN trial presented at ASCO. Progression free survival was almost doubled from a median of 5.4 to 10.2 months, while tumour response was significantly increased from 12.8% with interferon alone to 31.4% when Avastin was added to the treatment regimen.

Another study revealed that Avastin showed promising efficacy in terms of progression-free survival as first-line treatment in colorectal cancer patients when added to FOLFIRI. Median progression-free survival was 11.1 months, the overall response rate was 53% and 33% of patients had stable disease, according to results based on a trial which enrolled 209 patients at 31 centres worldwide between April and November 2005.

A third study noted that adding Avastin to cisplatin and gemcitabine produced a modest improvement in a measure of survival of people with non-small-cell lung cancer. However the study showed that both the standard dose and a lower dose of the drug, in combination with the chemotherapy, were equally effective, which could have negative financial implications for Roche.

Onto Herceptin (trastuzumab) and a study noted that the drug, used prior to surgery for breast cancer and given in combination with chemotherapy, could reduce the number of mastectomies.

Researchers found that the drug completely eradicated the tumour in nearly twice as many patients (43%) as when chemotherapy was used on its own (23%).

Roche’s partner Genentech also announced updated results from a joint analysis of two Phase III clinical trials studying Herceptin for the adjuvant treatment of HER2-positive breast cancer which evaluated four cycles of doxorubicin and cyclophosphamide followed by paclitaxel, either every three weeks or weekly for 12 weeks, compared with the same regimens plus 52 weeks of Herceptin in nearly 4,000 patients with HER2-positive breast cancer.

The results showed that the addition of Herceptin to standard adjuvant therapy continued to significantly reduce the risk of breast cancer recurrence, the primary endpoint of the studies, by 52% in women with HER2-positive, node-positive breast cancer, compared to patients who received standard adjuvant therapy alone. At four years of follow-up, 85.9% of women treated with Herceptin plus chemotherapy were disease free, compared to 73.1% of women treated with chemotherapy alone.

Also, early clinical results from a Phase II trial of the promising new cancer medicine pertuzumab, a HER dimerisation inhibitor, show substantial anti-tumour activity in patients with pre-treated HER2 positive breast cancer, when combined with Herceptin. The study showed that one in five patients responded to pertuzumab treatment and one in five also had stabilisation of their disease lasting six months or more.

Elsewhere at ASCO, Roche said that a follow-up analysis tracking the outcome of patients with aggressive non-Hodgkin’s lymphoma who were treated with the innovative cancer therapy MabThera (rituximab) over seven years ago “has revealed exciting results”. This analysis of the original Phase III study has shown that 53% of the patients treated with MabThera were still alive after seven years compared with just over a third (36%) of patients who had received chemotherapy alone. This means that for every 100 patients with aggressive NHL, 17 more patients would be alive at seven years due to MabThera. The analysis also demonstrated that more MabThera treated patients were in remission at seven years compared to chemotherapy alone, 52% versus 29%.

Another highlight concerned Roche’s Bondronat (ibandronic acid), which was shown to prevent the bone loss caused by anastrozole in women with surgically treated breast cancer, which can lead to bone fractures.

The study also found that the treatment significantly increased bone mineral density in the treated women. Anastrozole, which is AstraZeneca’s Arimidex, is an effective breast cancer treatment, Roche notes, but its use can cause side-effects with a decline in bone mineral density and an increased risk of bone fracture in some women.

Now that ASCO has ended, analysts will now be looking at how Roche’s portfolio is holding up and it will be interesting to see whether they agree with William Burns, chief executive of the firm's pharmaceutical unit, who does not see its competitive advantage threatened by any new products presented at the conference.