Ann: Q3 2023 Business Update to Accompany Quarterly Results, page-62

Ok thanks. But isn't today's report only interim and not the whole data in it?

fyi

In 2019: https://www.edisongroup.com/research/prostate-programmes-boosted/23842/

Fractionated dosing improved tolerability and efficacy

When 177Lu-huJ591 was administered as a single infusion, the maximum tolerated dose (MTD) was 70 mCi/m2 and 11–12% of subjects treated at 65 or 70 mCi/m2 achieved at least a 50% reduction in PSA count (referred to as a biochemical response). The dose-limiting toxicity was reversible myelosuppression, a condition where bone marrow activity is decreased, resulting in fewer red blood cells, white blood cells and platelets.

[...]

Efficacy improved

In addition to improved tolerability, the higher total doses that were able to be administered as a result of dose fractionation resulted in improved efficacy; 21% of subjects who received the second-highest dose (2x40 mCi) and 46% of subjects treated at the highest dose of 2x45 mCi/m2 experienced a 50% reduction in PSA (Exhibit 3, right hand side box).2 This compares to response rates of less than 15% for the maximum tolerated single shot doses (65 and 70 mCi/m2).

Longer survival reported for huJ591 than PSMA617

If approved, TLX591 (177Lu-huJ591) may face competition in the prostate cancer space from Endocyte’s small molecule therapeutic 177Lu-PSMA-617, which also binds to the PSMA receptor (Endocyte was acquired by Novartis for~US2.1bn in December 2018). In June 2018 Endocyte enrolled the first patient in a 750-patient global Phase III study of 177Lu-PSMA-617 in patients with PSMA-positive mCRPC who had failed or refused prior chemotherapy. The dose in the Phase III study is 7.4GBq every six weeks for up to six cycles. Endocyte is using Telix’s TLX591-CDx kit to screen patients for enrolment into the trial.

Endocyte reported preliminary data at ASCO in June 2018 from a Phase II study of PSMA617 in patients who had progressed after conventional therapies, including 88% who had progressed after chemotherapy. Interim results from 50 patients after a median of four cycles of PSMA617 included 62% (31/50) with at least a 50% PSA decline, including 40% with a PSA decline of at least 80%. Rates of grade 3–4 haematological toxicities reported included thrombocytopenia (10%), anaemia (10%) and neutropenia (6%). The treatment was well tolerated, with the most common side effect being grade 1–2 dry mouth reported by 68% of subjects (66% grade 1, 2% grade 2).

[...]

Despite the high response rates, the median OS rates reported from PSMA617 studies have typically been 15 months or less6. This compares to 43–48 months for high-dose fractionated TLX591, including ~28 months in post chemotherapy patients and ~48 months in chemotherapy-naïve patients (see previous pages).