Amgen's pipeline boosted by new denosumab data

US biotechnology major Amgen has maintained a strong presence at the 2009 joint European Cancer Organization/European Society of Medical Oncology (ECCO-ESMO) meeting in Berlin, Germany, where it presented data on lead pipeline candidate, denosumab. After getting a positive recommendation from a US Food and Drug Administration panel in August, Amgen is widely expected to get marketing approval for the drug, the proposed brand name for which is Prolia.

The company presented solid data on denosumab from a Phase III study that was conducted in 1,776 advanced cancer patients with solid tumors (not including breast and prostate cancer) or multiple myeloma. Top-line results from this study were presented in August 2009. Overall results were good, with denosumab not causing any imbalance in overall survival (or disease progression. Results showed that the median time to first on-study skeletal-related event was 20.6 months for patients receiving denosumab and 16.3 months for those treated with Novartis' Zometa (zoledronic acid). These results are statistically significant for non-inferiority.

Denosumab also delayed the median time to first on-study SRE or hypercalcemia of malignancy (HCM) compared to Zometa. The median time to first on-study SRE or HCM was 19 months for denosumab versus 14.4 months for Zometa.

Denosumab's safety profile also appeared to be in line with that of Zometa's. Adverse events rates (96% denosumab, 96% Zometa) and serious adverse events (63% denosumab, 66% Zometa) were similar between the two treatment groups. Rates of osteonecrosis of the jaw (ONJ) were balanced and infrequent in both treatment groups (10 patients receiving denosumab versus 11 patients receiving Zometa).

Amgen also presented detailed results from a Phase III, head-to-head trial evaluating denosumab versus Zometa in the treatment of bone metastases in 2,046 patients with advanced breast cancer that met its primary and secondary endpoints and demonstrated superior efficacy compared to Zometa.

Denosumab showed superiority in delaying the time to the first on-study SREs and also in delaying the time to first-and-subsequent SREs. Both results were statistically significant. Importantly, a lower incidence of renal toxicity and acute phase reactions were seen in the denosumab arm.

Denosumab also delayed the median time to first on-study SRE or HCM compared to Zometa. Once again, Denosumab's safety profile appeared to be in line with that of Zometa's. Adverse events rates (96% denosumab, 97% Zometa) and serious adverse events (44% denosumab, 46% Zometa) were similar between the two treatment groups. Rates of osteonecrosis of the jaw (ONJ) were infrequent in both treatment groups (20 patients receiving denosumab versus 14 patients receiving Zometa).

Denosumab is the most prized pipeline candidate at Amgen, note analysts at Zacks Equity Research. Currently, the candidate's New Drug Application is pending with the FDA which has established an action date of October. Amgen has an agreement with UK drug giant GlaxoSmithKline the commercialization of the drug for emerging markets such as China, Brazil, India and South Korea. 'We have a Neutral rating on Amgen,' the analysts say.