Drug Update · Oncology

FDA Approves Olaparib for HRR‑mutated mCRPC: HR 0.34 PFS (PROfound)

July 18, 2026

PROfound cohort A median PFS

7.4 months vs 3.6 months

PROfound HR (progression or death)

HR 0.34; 95% CI 0.25-0.47

PROfound cohort sizes

Cohort A 245 patients; Cohort B 142 patients

FDA‑listed MDS/AML incidence

Approximately 1.2%

FDA‑listed pneumonitis incidence

1.0%

Recommended dose

300 mg orally twice daily

Clinical Perspective

Medical oncologists and urologic oncologists treating men with metastatic castration‑resistant prostate cancer should document HRR gene status (including BRCA1/2 and other prespecified HRR genes) using an FDA‑approved companion diagnostic to identify patients eligible for olaparib therapy ^[3]^[4]. The FDA approval supports use of olaparib in patients who have progressed after enzalutamide or abiraterone, based on PROfound results showing longer imaging‑based PFS in cohort A (median 7.4 vs. An unanswered question for clinical practice is how best to integrate olaparib with other approved regimens (including combinations with abiraterone and corticosteroids where indicated) and how to operationalize broad biomarker testing for HRR genes in routine care?

Dr. Rahul Verma · Oncology

The FDA has approved olaparib (LYNPARZA) for the treatment of adult patients with deleterious or suspected deleterious germline or somatic homologous recombination repair (HRR) gene‑mutated metastatic castration‑resistant prostate cancer (mCRPC) who have progressed following prior treatment with enzalutamide or abiraterone ^[3]^[4]. The decision was supported by the randomized phase 3 PROfound trial, which showed imaging‑based progression‑free survival benefit in cohort A: median PFS 7.4 months with olaparib versus 3.6 months with physician’s choice of enzalutamide or abiraterone (hazard ratio for progression or death 0.34; 95% CI, 0.25 to 0.47) ^[1]^[3].

Clinical Context

Olaparib is an oral poly (ADP‑ribose) polymerase (PARP) inhibitor developed and marketed by AstraZeneca (LYNPARZA) ^[3]. The agent inhibits PARP enzymes, including PARP1, PARP2, and PARP3, interfering with single‑strand DNA break repair and increasing cytotoxicity in tumor cells with defects in homologous recombination repair such as BRCA1/2 and other HRR genes; the label describes these mechanisms and preclinical correlations with BRCA1/2 and ATM deficiencies ^[4]. The FDA prescribing information and DailyMed highlights list multiple approved oncologic indications for olaparib and specify selection of patients based on an FDA‑approved companion diagnostic for HRR or BRCA mutations; the prostate‑cancer indication covers patients who progressed on novel hormonal agents such as enzalutamide or abiraterone ^[3]^[4].

Key Findings

The PROfound trial was a randomized, open‑label, phase 3 study enrolling men with mCRPC who had disease progression on an androgen‑receptor signaling inhibitor and whose tumors harbored prespecified alterations in genes involved in homologous recombination repair ^[1]. Cohort A (n=245) included patients with alterations in BRCA1, BRCA2, or ATM and was the primary analysis population. In cohort A, olaparib significantly prolonged imaging‑based progression‑free survival per blinded independent central review: median PFS was 7.4 months with olaparib versus 3.6 months with physician’s choice of enzalutamide or abiraterone, hazard ratio for progression or death 0.34; 95% CI, 0.25 to 0.47; P<0.001 ^[1]. The NEJM report also notes significant benefits for confirmed objective response rate and time to pain progression in the olaparib arm; overall survival median was 18.5 months with olaparib and 15.1 months in the control arm in cohort A, with 81% of control patients crossing over to receive olaparib after progression ^[1]. These data formed the basis for the regulatory approval for HRR‑mutated mCRPC after prior enzalutamide or abiraterone ^[3]^[4].

Safety & Tolerability

The NEJM primary publication identified anemia and nausea as the main toxic effects among patients receiving olaparib in PROfound ^[1].
The FDA prescribing information and DailyMed highlight list specific warnings and adverse events: myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) occurred in approximately 1.2% of patients exposed to Lynparza and the majority of events had a fatal outcome; pneumonitis occurred in 1.0% of patients and some cases were fatal; venous thromboembolism (VTE), including pulmonary embolism, occurred and VTE was reported in 8% of patients with mCRPC; hepatotoxicity, including drug‑induced liver injury, is described ^[2]^[3].
The label and highlights also list the most common adverse reactions (≥10%) across indications, including nausea, fatigue (including asthenia), anemia, vomiting, diarrhea, decreased appetite, headache, dysgeusia, cough, neutropenia, dyspnea, dizziness, dyspepsia, leukopenia, and thrombocytopenia ^[2]^[3].

Study Design

PROfound was a randomized, open‑label, phase 3 trial enrolling men with mCRPC and qualifying alterations in prespecified homologous recombination repair genes; cohort A (245 patients) contained those with BRCA1, BRCA2, or ATM alterations and cohort B (142 patients) included alterations in 12 other prespecified genes ^[1]. Patients were randomized 2:1 to olaparib or the physician’s choice of enzalutamide or abiraterone (control); the primary end point was imaging‑based progression‑free survival in cohort A assessed by blinded independent central review ^[1]. The NEJM publication reports median PFS 7.4 vs. 3.6 months and HR 0.34 (95% CI, 0.25–0.47) in cohort A ^[1].

FAQ

Q1 What is olaparib (LYNPARZA) approved for?

Olaparib (LYNPARZA) is approved for multiple oncologic indications; relevant to prostate cancer, it is indicated for the treatment of adult patients with deleterious or suspected deleterious germline or somatic homologous recombination repair (HRR) gene‑mutated metastatic castration‑resistant prostate cancer (mCRPC) who have progressed following prior treatment with enzalutamide or abiraterone. The indication requires selection of patients based on an FDA‑approved companion diagnostic for HRR or BRCA mutations.

Q2 How does olaparib work?

Olaparib is a poly (ADP‑ribose) polymerase (PARP) inhibitor that targets PARP enzymes including PARP1, PARP2, and PARP3; inhibition impairs single‑strand DNA break repair and increases DNA damage in tumor cells. Tumors with defects in homologous recombination repair genes such as BRCA1, BRCA2, or ATM are selectively more susceptible to PARP inhibition, producing cytotoxicity and antitumor activity that formed the biological rationale for use in HRR‑mutated cancers.

Q3 What is the recommended dose of olaparib for mCRPC?

The FDA‑approved recommended dosage of LYNPARZA (olaparib) is 300 mg taken orally twice daily with or without food; dose modifications for renal impairment and concomitant CYP3A inhibitors are described in the full prescribing information. For the prostate cancer indication, patients receiving Lynparza should also receive a gonadotropin‑releasing hormone (GnRH) analog concurrently or should have had bilateral orchiectomy when appropriate. Clinicians should consult current prescribing information for complete dosing guidance.

Q4 What are the side effects I should counsel patients about?

Adverse events reported in the PROfound trial included anemia and nausea as prominent toxic effects in patients who received olaparib. The prescribing information and highlights list additional important risks and adverse events across populations: myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) occurred in approximately 1.2% of exposed patients and may be fatal; pneumonitis occurred in about 1.0% and has included fatal cases; venous thromboembolism (VTE), including pulmonary embolism, was reported and VTE incidence was 8% in patients with mCRPC; hepatotoxicity/ drug‑induced liver injury is also described. The label additionally lists common adverse reactions (≥10%) such as nausea, fatigue, anemia, vomiting, diarrhea, decreased appetite, headache, dysgeusia, cough, neutropenia, dyspnea, dizziness, dyspepsia, leukopenia, and thrombocytopenia. Monitor hematologic parameters and other relevant safety labs per prescribing information and discontinue or adjust therapy for confirmed severe toxicities.

Clinicians should consult current prescribing information for complete dosing guidance.

FDA Approves Olaparib for HRR‑mutated mCRPC: HR 0.34 PFS (PROfound)

FDA Approves Olaparib for HRR‑mutated mCRPC: HR 0.34 PFS (PROfound)

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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