The US Food and Drug Administration (FDA) has granted breakthrough therapy designation to Novartis177Lu-PSMA-617 to treat metastatic castration-resistant prostate cancer (mCRPC).

An investigational radioligand therapy, ¹⁷⁷Lu-PSMA-617 is a combination of a targeting compound and a therapeutic radioisotope.

The drug attaches to prostate cancer cells that express prostate-specific membrane antigen, on entering the bloodstream. Once attached, emissions from the radioisotope destroy tumour cells, thereby interrupting their ability to replicate and/or causing cell death.

The FDA based its decision on positive results from the Phase III VISION study of the drug given along with the standard of care (SOC) in 831 progressive PSMA-positive mCRPC patients.

The global, prospective, randomised, open-label, multi-centre trial analysed the efficacy and safety of the intravenous ¹⁷⁷Lu-PSMA-617 given every six weeks for a maximum of six cycles along with SOC.

Data from the trial showed that ¹⁷⁷Lu-PSMA-617 substantially enhanced overall survival (OS) and radiographic progression-free survival (rPFS) in participants.

A 38% reduction in death risk was observed in the treatment arm as compared to the SOC only arm.

Furthermore, a 60% rPFS risk reduction in those receiving ¹⁷⁷Lu-PSMA-617 treatment was noted, which is statistically significant.

Median OS of 15.3 months was reported in ¹⁷⁷Lu-PSMA-617 treatment arm as against 11.3 months in SOC only arm.

The median rPFS was 8.7 months in subjects who received ¹⁷⁷Lu-PSMA-617 plus SOC versus 3.4 months in those who were given SOC only.

Novartis noted that FDA grants breakthrough therapy designation to treatments that are being analysed for serious ailments in which early clinical data show the potential for significant improvement over existing medicines.

Currently, the radioligand drug is being analysed in two other trials as the early line for mCRPC in the pre-taxane setting and in the metastatic hormone-sensitive setting.

Last month, Novartis and Molecular Partners commenced the Phase II/III EMPATHY clinical trial of a new DARPin therapeutic candidate, ensovibep (MP0420), to treat Covid-19.