Perspective's lead balloon
Radiopharmaceuticals continue to generate deals – just this week Novartis licensed Ratio Therapeutics' preclinical SSTR2-targeting project – but one biotech definitely out of favour is Perspective Therapeutics. Thursday's news that Perspective's own anti-SSTR2 project, 212Pb-VMT-α-NET, had generated just one objective response among nine SSTR2-expressing neuroendocrine tumour patients in a phase 1/2 trial sent the group's stock crashing 45%. This means that Perspective, which a year ago burst onto the scene by ditching its brachytherapy business and acquiring a radiotherapeutic from the Mayo Clinic, has this year seen its shares climb from $4 to $19 in July, and then fall back to just over $3 today. The data are especially disappointing as an earlier 212Pb-VMT-α-NET trial reported a confirmed ORR of 62% among 13 patients, though that had been carried out in India and was investigator-sponsored. Perspective will now move to dose escalation in its study, given the absence of dose-limiting toxicities. Novartis's SSTR2-targeting Lutathera is approved for neuroendocrine tumours, but uses the beta-emitter lutetium-177, whereas the Perspective project uses lead-212. Perspective claims that lead-212 is an alpha-emitter, but in fact this radioisotope also undergoes beta decay; the latest data aren't a great endorsement of this approach.
552
