Lynparza Meets Primary Endpoint in Phase III PROfound Trial

By Rajaneesh K. Gopinath, Ph.D.

The world’s first PARP inhibitor to be approved by the USFDA for the treatment of BRCA-mutated advanced ovarian cancer, succeeded in the phase III trials of breast and pancreatic cancers too. Its good performance has now extended to yet another phase III trial, this time in the treatment of prostate cancer in men.

On August 7th, AstraZeneca and MSD Inc. announced that Lynparza (Olaparib) met the primary end point in the PROfound trial, a prospective, multicenter, randomized, open-label, phase III trial. The study involved men with metastatic castration-resistant prostate cancer (mCRPC) which harbors a homologous recombination repair (HRR) gene mutation and have progressed on prior treatment with new hormonal anticancer treatments. This result earns the drug that rare honor of registering positive phase III data in four different cancer types: ovarian, breast, pancreatic and prostate.

Metastatic Castration-Resistant Prostate Cancer

Prostate cancer is one of the most common types of cancer in men often driven by androgens, the male sex hormones, including testosterone. In fact, the androgen receptor helps many prostate cancer cells survive and is a common anticancer target. The mCRPC is a condition where the prostate cancer metastasizes to other parts of the body despite androgen-deprivation therapy. Lynparza is a first-in-class PARP inhibitor codeveloped and commercialized by a global strategic oncology collaboration between AstraZeneca and MSD Inc. The inhibitor blocks the DNA damage response (DDR) in tumors that harbor a deficiency in HRR. This leads to unrepaired, DNA single-strand and double-strand breaks resulting in cancer cell death.

PROfound Trial (NCT02987543)

The phase III trial tested the efficacy and safety of Lynparza versus enzalutamide or abiraterone in male patients with mCRPC that harbors a qualifying tumor mutation in one of 15 genes involved in the HRR pathway, such as BRCA1/2, ATM and CDK12. The trial showed that Lynparza resulted in a statistically-significant and clinically-meaningful improvement in the primary endpoint of radiographic progression-free survival (rPFS). The safety and tolerability were generally consistent with previous trials.

José Baselga, Executive Vice President, Oncology R&D, said: “For men with metastatic castration-resistant prostate cancer the disease remains deadly, especially in those who have failed on a new hormonal anticancer treatment. This trial is the only positive phase III trial of any PARP inhibitor in metastatic castration-resistant prostate cancer, where the need for new, effective therapies is high. The PROfound trial also demonstrates the potential value of genomic testing in this at-risk patient population. We look forward to discussing these results with global health authorities soon.”

BRACAnalysis CDx® as a Companion Diagnostic

In light of this development, Myriad Genetics, Inc. has announced that it will file a supplementary Premarket Approval Application (sPMA) with the USFDA to authorize BRACAnalysis CDx as a companion diagnostic test for Lynparza for this indication. BRACAnalysis CDx has been a consistent USFDA approved companion diagnostic for Lynparza for other indications previously.

References

1. https://www.astrazeneca.com/media-centre/press-releases/2019/lynparza-phase-iii-profound-trial-in-hrr-mutation-selected-metastatic-castration-resistant-prostate-cancer-met-primary-endpoint-07082019.html
2. https://www.mrknewsroom.com/news-release/oncology/lynparza-olaparib-phase-3-profound-trial-hrr-mutation-selected-metastatic-cast
3. https://myriad.com/investors/news-release/news-release-detail/?newsItemId=20541

Author

Rajaneesh K. Gopinath