New Treatments for Ovarian Cancer: PARP Inhibitors, Immunotherapy, and Beyond — Cost, Top Hospitals & Success Rates | MyMedicPlus

Ovarian cancer is the fifth most common cause of cancer death in women globally and the most lethal of the gynaecological cancers, accounting for approximately 180,000 deaths worldwide annually. Its lethality stems from its typically late presentation: over 75% of ovarian cancers are diagnosed at stage III or IV (widespread peritoneal or distant metastatic disease), as the cancer produces few specific symptoms in early stages. Despite this challenge, the past decade has witnessed transformative advances in ovarian cancer treatment through the clinical validation and approval of targeted therapies — particularly PARP (poly ADP-ribose polymerase) inhibitors — that exploit fundamental vulnerabilities in ovarian cancer cell DNA repair mechanisms.

High-grade serous ovarian carcinoma (HGSC), the most common and aggressive subtype (representing 70–80% of all ovarian cancers), is characterised by near-universal TP53 mutations and frequent homologous recombination deficiency (HRD) — a state of impaired DNA double-strand break repair arising from mutations in BRCA1, BRCA2, and other HRD pathway genes. Approximately 20% of HGSC patients carry germline BRCA1/2 mutations, and an additional 20–30% have somatic BRCA mutations or other HRD-causing alterations. This HRD landscape creates a vulnerability that PARP inhibitors exploit through synthetic lethality: PARP enzymes are the backup DNA repair pathway that HRD-deficient cells depend upon; blocking PARP in these cells leaves them unable to repair DNA damage and results in cell death.

The landmark approval of olaparib (Lynparza) as maintenance therapy following platinum-based chemotherapy in BRCA-mutated ovarian cancer (SOLO-1 trial, 2018) marked the beginning of the PARP inhibitor era in ovarian oncology. Subsequent approvals of niraparib (Zejula), rucaparib (Rubraca), and veliparib, along with extended indications beyond BRCA mutation to all HRD-positive and eventually all-comer populations, have established PARP inhibitor maintenance as a standard-of-care component of first-line ovarian cancer treatment.

Most newly diagnosed advanced ovarian cancer patients now receive a treatment programme consisting of debulking surgery (cytoreductive surgery or interval debulking surgery), platinum-taxane based chemotherapy (carboplatin-paclitaxel), optional addition of bevacizumab (anti-VEGF antiangiogenic), followed by PARP inhibitor maintenance therapy — a strategy that has achieved median progression-free survival of over 3 years in BRCA-mutated patients in SOLO-1 (previously approximately 13 months with platinum-doublet chemotherapy alone), representing a two-fold improvement in progression-free survival.

PARP inhibitors and modern ovarian cancer treatments are used in the following clinical settings: first-line maintenance therapy after response to platinum-based chemotherapy in stage III–IV ovarian cancer (highest benefit in BRCA-mutated and HRD-positive patients); recurrent platinum-sensitive ovarian cancer (patients who relapse more than 6 months after last platinum, for whom re-treatment with platinum and PARP inhibitor maintenance substantially extends time to next progression); and treatment of germline BRCA-mutated ovarian cancer at any line of treatment.

Beyond ovarian cancer, PARP inhibitors are approved for BRCA-mutated breast cancer, prostate cancer, and pancreatic cancer — reflecting the broad principle that BRCA/HRD status rather than tumour histology determines PARP inhibitor sensitivity. Bevacizumab targeting VEGF-A inhibits tumour angiogenesis in ovarian cancer and is approved in combination with chemotherapy and as maintenance in both first-line (with platinum response) and recurrent settings. Novel targets being investigated include folate receptor alpha (targeted by mirvetuximab soravtansine, an antibody-drug conjugate recently approved for folate receptor-positive platinum-resistant ovarian cancer based on the MIRASOL trial), immune checkpoint inhibitors for specific patient subgroups, and antibody-drug conjugates targeting other ovarian cancer-specific surface antigens.

Candidacy for specific targeted therapies in ovarian cancer requires comprehensive molecular profiling. All newly diagnosed ovarian cancer patients should have germline BRCA1/2 testing and tumour somatic mutation testing. Patients with germline or somatic BRCA mutations achieve the greatest benefit from PARP inhibitor maintenance after first-line chemotherapy (HR for PD progression 0.33 with olaparib in SOLO-1 versus 0.43 in HRD-positive non-BRCA group). Homologous recombination deficiency (HRD) testing using validated commercial assays (Myriad myChoice CDx, Foundation Medicine) further stratifies patients — HRD-positive BRCA-wild-type patients benefit from PARP inhibitors, while HRD-negative patients have limited benefit and bevacizumab-based maintenance may be preferred.

For recurrent platinum-sensitive ovarian cancer, prior platinum therapy history, response to the most recent platinum treatment, and molecular status guide treatment selection. Patients with platinum-resistant ovarian cancer (relapse within 6 months of last platinum) have more limited targeted options — mirvetuximab soravtansine for folate receptor-positive tumours and clinical trial participation are the key options in this challenging setting. Performance status, organ function, and comorbidities influence tolerability of specific agents.

First-line treatment for advanced ovarian cancer follows a sequential strategy. Primary debulking surgery aims to achieve complete macroscopic cytoreduction (no visible residual tumour) as the most important surgical prognostic factor — complete resection versus partial resection is associated with a 50% improvement in median overall survival. In patients where upfront complete resection is not achievable, neoadjuvant chemotherapy followed by interval debulking surgery (IDS) achieves equivalent outcomes in appropriately selected patients per the EORTC 55971 and CHORUS trials.

Post-surgery chemotherapy with carboplatin (AUC 5–6) plus paclitaxel (175 mg/m2) every 3 weeks for 6 cycles remains the foundational chemotherapy backbone. Addition of bevacizumab (7.5–15 mg/kg q3w during chemotherapy and continued as maintenance for 12–18 months) improves PFS particularly for high-risk patients (stage IIIB/C and IV) per GOG-0218 and ICON7. Following completion of platinum-based chemotherapy plus optional bevacizumab, PARP inhibitor maintenance (olaparib, niraparib, or rucaparib) is selected based on BRCA/HRD status and whether bevacizumab was co-administered. The PAOLA-1 trial established olaparib plus bevacizumab maintenance as the preferred option for HRD-positive patients who received bevacizumab during chemotherapy, achieving a 37.2-month median PFS in HRD-positive patients. The sequencing of maintenance therapies — PARP inhibitors following bevacizumab-containing chemotherapy, or bevacizumab maintenance in BRCA-wild-type patients — is individualised based on molecular profile and prior treatment response, reflecting a shift toward biomarker-directed maintenance strategies in advanced ovarian cancer management.

The introduction of PARP inhibitor maintenance therapy has fundamentally improved progression-free survival outcomes for ovarian cancer patients. SOLO-1 reported 5-year progression-free survival of 48% for BRCA-mutated patients receiving olaparib maintenance versus 21% for placebo — meaning that nearly half of BRCA-mutated patients remained free of progression at 5 years with PARP inhibitor maintenance, compared to only 1 in 5 with observation. While overall survival data maturation requires longer follow-up, multiple analyses are demonstrating emerging OS benefits with PARP inhibitor-based maintenance strategies.

For patients with recurrent platinum-sensitive ovarian cancer, second-line PARP inhibitor maintenance after platinum re-treatment has demonstrated consistent benefit across all patients (regardless of BRCA status) based on ARIEL3 and STUDY 19 trials. Mirvetuximab soravtansine for folate receptor-positive platinum-resistant ovarian cancer achieved a response rate of 32.4% and median PFS of 5.6 months in MIRASOL — significantly superior to chemotherapy in this setting where historical response rates were 10–15%. Collectively, these advances have converted the ovarian cancer treatment landscape from one of uniformly poor outcome to one of increasingly individualised and effective sequential targeted therapy.

PARP inhibitors are generally well-tolerated maintenance therapies with manageable toxicity profiles that differ from conventional chemotherapy. Common adverse effects of olaparib include nausea (77%), fatigue (66%), anaemia (44%), and vomiting (35%) — most grade 1–2 and manageable with anti-nausea medication, dose reduction (10% of patients), and supportive care. Haematological toxicity (anaemia, thrombocytopenia, neutropenia) is more prominent with niraparib compared to olaparib, requiring baseline weight-based dosing adjustments.

A rare but important long-term risk is myelodysplastic syndrome (MDS) or acute myeloid leukaemia (AML) — occurring in approximately 1.5% of PARP inhibitor-treated patients in long-term follow-up studies, compared to 0.5% in chemotherapy-only control arms. While uncommon, patients on long-term PARP inhibitor maintenance should have periodic blood count monitoring for early detection. Bevacizumab-related toxicities include hypertension (managed with antihypertensives), proteinuria, and rare but serious risks of gastrointestinal perforation (1–2%) and thrombosis. Cytoreductive surgery for ovarian cancer carries standard major abdominal surgery risks including anastomotic leak, bowel obstruction, and thromboembolic complications, with specialist surgical oncology teams achieving the best outcomes.

Following completion of primary treatment (surgery plus chemotherapy), ovarian cancer patients entering PARP inhibitor maintenance therapy are seen every 12 weeks for clinical assessment, CA-125 measurement (rising CA-125 is often the first marker of recurrence), and toxicity monitoring. CT scanning is performed every 6 months during maintenance to monitor for subclinical disease progression. Patients who complete a defined course of PARP inhibitor maintenance (typically 2 years for olaparib) enter a surveillance programme with less frequent visits.

Due to the high relapse rates in advanced ovarian cancer, most patients will eventually experience disease recurrence and require further treatment. The watch and treat approach — characterising recurrence precisely through biopsy (if feasible) to confirm histology and re-test for current actionable mutations — allows selection of the most appropriate next-line therapy. Sequential deployment of maintenance therapies across multiple lines of treatment, guided by evolving biomarker landscape and individual resistance mechanisms, is the optimal strategy for prolonging overall survival. Gynaecological oncology multidisciplinary teams at specialist cancer centres provide the best framework for this complex sequential management.

Targeted therapies for ovarian cancer, particularly PARP inhibitors, represent significant costs. Olaparib (Lynparza) monthly list price in the United States is approximately USD 17,000–20,000. Niraparib costs approximately USD 14,000 monthly. In the UK, NICE has approved olaparib for BRCA-mutated ovarian cancer maintenance via the Cancer Drugs Fund with patient access guaranteed through NHS at no direct patient cost. In Australia, olaparib is PBS-listed for eligible patients.

For patients in middle-income countries and those without insurance coverage, access to PARP inhibitors remains a major challenge. Generic olaparib (available in India following patent challenges) and biosimilar bevacizumab programmes have significantly reduced prices in some markets — generic olaparib in India is available at approximately 5–10% of the US listed price. Several oncology centres in India (Tata Memorial Centre, AIIMS, Apollo Cancer Centres) provide comprehensive ovarian cancer treatment including PARP inhibitor maintenance at costs that are 70–80% lower than comparable programmes in the US or Western Europe, making medical tourism for ovarian cancer treatment an increasingly viable option for patients from developed countries with inadequate insurance coverage.

For patients not eligible for or declining PARP inhibitors, alternatives for first-line ovarian cancer maintenance include observation (standard of care before PARP inhibitor approval, associated with shorter PFS), bevacizumab alone (appropriate for HRD-negative patients or those who cannot tolerate PARP inhibitors), and clinical trial participation testing novel agents or combinations. For recurrent disease, liposomal doxorubicin, gemcitabine, topotecan, and docetaxel are active chemotherapy options. Clinical trials of novel antibody-drug conjugates (XMT-1536, IMGN151), bispecific antibodies, CAR-T cell therapies targeting ovarian cancer antigens, and oncolytic virus therapies represent the next generation of approaches being tested.

Complementary approaches including integrative oncology (exercise, mind-body interventions, nutritional optimisation) are important quality-of-life supporting strategies throughout ovarian cancer treatment. Genetic counselling for all patients with BRCA-mutated ovarian cancer and cascade testing of first-degree relatives enables early detection and prevention strategies for at-risk family members — including risk-reducing salpingo-oophorectomy for BRCA-positive women who have completed childbearing, which reduces ovarian cancer risk by 80–96%.