On 23 March, Novartis announced that the US Food and Drug Administration (FDA) had approved its PLUVICTO (previously referred to as 177Lu-PSMA-617) for the treatment of adult patients with prostate-specific membrane antigen-positive (PSMA) metastatic castration-resistant prostate cancer (mCRPC). As the first targeted radioligand therapy for PSMA-mCRPC patients, Novartis’s PLUVICTO sets itself apart as a favourable option for post-first-line mCRPC treatment due to its markedly improved radiographic progression-free survival (PFS) of 8.7 months, compared with 3.4 months observed in the control arm (best standard of care) of the VISION trial.
PLUVICTO’s FDA approval extends pressure on POINT Biopharma’s rival targeted radioligand therapy, PSMA [Lu-177]-PNT2002, whose estimated primary completion date for its randomisation phase is not until next March. Data from its lead-in phase, however, are anticipated to be made available before Q1 2023, with investors expecting positive results on the back of PLUVICTO’s success. Last month, POINT published positive dosimetry results with its highest radiation absorbed dose isolated to the lacrimal glands (1.2 Gy/GBq). This result was 57% lower than that reported for PLUVICTO and overall indicates a low organ dose absorption for adult patients receiving therapy. According to Dr Joe McCann, CEO of POINT Biopharma: “The dosimetry data generated in the SPLASH lead-in validates the published literature and overall approach POINT has leveraged to accelerate the clinical development program.”
Although POINT’s SPLASH trial currently intensifies the radioligand competition for mCRPC patients, this intensity may reduce over time due to the two ongoing pivotal Phase III studies evaluating PLUVICTO in earlier treatment lines. An FDA approval for first-line will make Novartis’s radioligand therapy incontestable, leaving little room for Point BioPharma’s PSMA [Lu-177]-PNT2002 in the mCRPC setting. For POINT’s PSMA [Lu-177]-PNT2002 to obtain a sizeable share of the post-first-line market and encourage a switch from PLUVICTO, it must demonstrate a significantly high clinical performance and cost-efficacy. PSMA [Lu-177]-PNT2002 currently enjoys a clinical and commercial advantage over PLUVICTO due to its reduced dosage (6.8 GBq vs. 7.4 GBq), longer time between each cycle (eight weeks compared with six), and reduced number of cycles (four cycles compared with six). As such, reports of a similar or significantly improved rPFS in its lead-in phase data will present a marketing challenge for Novartis’s PLUVICTO for the radioligand blockbuster status in the mCRPC setting.
In general, the market footprint of both radioligands will be limited by the infrastructure available to produce these resource-intensive unsealed radiotherapy agents. A British Nuclear Medicine Society report published on 1 November last year flagged that many centres had undertaken some preparation for PLUVICTO, but only four of the 45 surveyed centres stated that they were ‘ready to start’. In addition, two of those ‘ready to start’ centres had no prior experience with Lu-177-based agents, including established LUTATHERA, and were thus unequipped for handling large volumes of Lu-177 pharmaceuticals. This hurdle will limit the initial uptake of radioligand therapy into clinical practice, which will undoubtedly be more evident in middle-income and developing economies.