Analysis shows Amgen's T-Vec reduced size of melanoma tumours
Amgen presented data at the Society of Surgical Oncology Annual Cancer Symposium showing that the experimental oncolytic immunotherapy talimogene laherparepvec (T-Vec) reduced the size of injected tumours and also non-injected tumours that had metastasised to other parts of the body in patients with metastatic melanoma. Study investigator Robert Andtbacka, who called the results "very encouraging," remarked "this is a new generation of oncolytic immunotherapy where you're seeing very robust responses in injected lesions but also robust responses in non-injected lesions."
The pre-specified retrospective analysis recorded tumour-level responses from a pivotal Phase III study evaluating talimogene laherparepvec in patients with injectable unresected stage IIIB, IIIC or IV melanoma compared to GM-CSF. Amgen noted that of 295 patients treated with talimogene laherparepvec, almost 4000 tumour lesions were included in the analysis. The company added that half of these lesions were injected with talimogene laherparepvec at least once, while the rest were not injected, including visceral tumour lesions involving solid organs such as the lungs and liver.
Results demonstrated that 64 percent of tumours injected directly with talimogene laherparepvec shrank by at least 50 percent, with 47 percent deemed a complete response. Meanwhile, 34 percent of the uninjected non-visceral tumour lesions shrank by at least 50 percent, with a complete response seen in 21 percent. In addition, 15 percent of visceral tumours were also reduced by at least 50 percent. "This indicates to us that we have activation of the immune system to fight these tumours at a distant site," Andtbacka said.
According to Amgen, there were 35 melanoma-related surgeries performed during the trial of which 30 percent successfully removed all residual disease. The company added that the most frequently observed adverse events in the study were fatigue, chills and pyrexia, while the most common serious adverse events included disease progression in both groups, and cellulitis and pyrexia in the talimogene laherparepvec group. Serious adverse events occurred in 26 percent of talimogene laherparepvec patients and 13 percent of those in the GM-CSF group.
Amgen expects to have data in the first half of this year showing whether talimogene laherparepvec helped patients in the study live longer. The company is also evaluating the therapy in combination with Bristol-Myers Squibb's melanoma drug Yervoy (ipilimumab) and has agreed to study it in combination with Merck & Co.'s anti-PD-1 immunotherapy MK-3475. "We are extremely excited about the data and the potential for combinations with other treatments," commented David Chang, Amgen's head of global oncology development.
For related analysis, see ViewPoints: More shots on goal – Merck & Co. steps up combination deals for MK-3475 and In Focus: The cancer immunotherapy race - Will Roche's breadth of portfolio prove decisive as Merck & Co. takes on a more streamlined approach to R&D?