Telix Pharmaceuticals (ASX:TLX) plans to accelerate the development of its radiopharmaceutical to treat the most aggressive form of brain cancer after encouraging early clinical trial results.

TLX101, a molecularly targeted radiation, has been used to treat eight patients in Australia and Europe with recurrent glioblastoma multiforme, Telix said.

The treatment seemed to slow cancerous growth, with the patients showing a progression-free survival of 4.3 months, while about two is typical in this patient population.

Three patients have died – two from cancer and one from COVID-19 – while the other is in follow-up care.

“We are very encouraged by these first dose cohort results,” said Telix chief medical officer Dr Colin Hayward.

“We observed multiple treatment responses in this lowest dose cohort, including patients with a reduction in tumour burden by imaging and prolonged disease stabilisation.

“Most importantly, we have seen clear evidence of anti-tumour effect at relatively low doses with no dosimetry or side-effect profile that would prevent planned higher therapeutic doses.”

At 10.39am, Telix shares were up one per cent to $3.92.