Telix sees more backing for LAT1

The recently Nasdaq-listed Australian radiopharmaceuticals expert Telix has seen more validation for LAT1 as a therapeutic target in brain cancer. The latest backing comes from Ipax-Linz, a small, uncontrolled, investigator-sponsored Austrian trial of TLX101 said to have substantiated a survival benefit seen in Telix's earlier ex-US Ipax-1 study.

The company's lead radiopharmaceutical projects use an antibody format, but TLX101 is a small molecule, and is one of only a handful of industry assets that target LAT1, according to OncologyPipeline. Pending ethics approval and a mid-year US IND submission, the company now wants to begin a registrational trial of TLX101 in patients with recurrent glioblastoma in the second half.

In the meantime, the phase 1/2 Ipax-2 study is continuing to enrol front-line glioblastoma patients, and has a mid-2025 primary completion date. On the basis of this Telix plans to start a pivotal first-line trial, Ipax-3, but according to its JP Morgan presentation the design of this is still being hammered out with the FDA.

Recurrent glioblastoma

In Ipax-1 TLX101 showed median overall survival of 13 months from the start of treatment, or 23 months from initial diagnosis, in an uncontrolled cohort of 10 patients with recurrent glioblastoma.

Now Ipax-Linz has backed this up, with eight subjects enrolled into this trial and treated with TLX101 plus external beam radiation therapy (EBRT) yielding mOS of 12.4 months from start of treatment, or 32.2 months from initial diagnosis, according to a Telix press release. Telix says this compares favourably against a historical mOS number of 9.9 months after treatment with EBRT alone.

LAT1, standing for large amino acid transporter 1, is a protein that transports large amino acids across cell membranes, and is overexpressed in some cancers. Telix is also developing a tracer for this marker; this uses fluorine-18, and it was used in Ipax-Linz to indicate whether patients had pathologically increased amino acid uptake.

TLX101 is labelled with iodine-131, and Telix also has a follow-on LAT1 radiopharmaceutical, TLX102, which uses the radioisotope astatine-211, and is in preclinical development. Meanwhile, OncologyPipeline reveals two other clinical-stage LAT1-targeting assets, but none with a radioconjugate design.

Biopharma projects targeting LAT1

Source: OncologyPipeline.