Three patients had a diagnosis of gastrointestinal stromal tumor, two had renal cell carcinoma, and one each had a diagnosis of colorectal adenocarcinoma, desmoid fibromatosis, and medullary thyroid carcinoma.

Cancers like thyroid cancer, renal cell carcinoma, that had activity at RET.

The selective RET kinase inhibitor is indicated for adults with metastatic non-small-cell lung cancer, and individuals aged 12 years or older with locally advanced or metastatic medullary thyroid cancer or advanced RET fusion-positive thyroid cancer that is unresponsive to or ineligible for radioactive iodine therapy.

Lung cancer decision The RET receptor tyrosine kinase inhibitor selpercatinib has been granted a positive opinion for use in patients with RET fusion-positive advanced NSCLC, as well as those with medullary thyroid or thyroid cancer with RET alterations.

In the phase I ARROW study, 29 patients with medullary thyroid cancer, 19 with non-small-cell lung cancer, two with papillary thyroid cancer, and one with paraganglioma – all carrying alterations in RET – were given BLU-667 orally at doses of 30–400 mg/day.

One patient had medullary thyroid cancer, with a RET M918T mutation and an acquired RET V804M gatekeeper resistance mutation, that had metastasized to the liver, while the other patient had KIF5B – RET fusion-positive non-small-cell lung cancer (NSCLC) with brain metastases.

Of the 82 participants enrolled in the dose-escalation part of the phase I study, 60% had RET fusion-positive cancers (most commonly non-small-cell lung cancer [NSCLC]), 35% had medullary thyroid cancer (MTC) with RET mutations, and the remaining 5% had other tumor types.

Cabozantinib should now be a routinely available option for National Health Service patients with inoperable, locally advanced, or metastatic medullary thyroid cancer, states the final appraisal determination for the agent.