The treatment landscape for platinum-resistant ovarian cancer has rapidly evolved into a biomarker-driven paradigm. Clinicians must now test for and choose between therapies targeting distinct markers like folate receptor alpha (mirvetuximab), HER2 (T-DXd), and PD-L1 (pembrolizumab), requiring a sophisticated sequencing strategy.

The traditional six-month timeframe for defining platinum sensitivity is being challenged. A growing theory suggests that tumors progressing while on a PARP inhibitor have a distinct biology that responds poorly to subsequent platinum, indicating a potential need to move directly to therapies like ADCs.

Despite multiple clinical trials, adding checkpoint inhibitors to frontline therapy for ovarian cancer has not demonstrated a proven survival benefit. The role of immunotherapy in this setting remains confined to rare subsets like DMMR or TMB-high tumors, and it is not standard practice for the general population.

The traditional practice of classifying recurrent ovarian cancer as 'platinum-sensitive' or 'platinum-resistant' based on a six-month treatment-free interval is rapidly becoming obsolete. The introduction of maintenance therapies like PARP inhibitors is changing tumor biology and response patterns, suggesting this simple time-based distinction no longer adequately reflects the clinical reality.

Real-world data shows that in platinum-sensitive ovarian cancer patients who have progressed on PARP inhibitors, subsequent platinum-based chemotherapy has a surprisingly low response rate of only 20%. This quantifies a significant opportunity for highly active ADCs to potentially replace platinum in this growing patient population.

Citing powerful long-term data from the SOFT and TEXT trials, some oncologists are leaning away from chemotherapy for premenopausal patients with intermediate Oncotype scores (e.g., <25). They argue that the substantial, proven benefits of ovarian function suppression (OFS) may be equivalent to the chemotherapy benefit seen in trials like TAILORx.

The B96 trial's positive outcome in historically immunotherapy-resistant ovarian cancer is not just about adding pembrolizumab. The regimen's success is attributed to the thoughtful use of continuous weekly paclitaxel, a form of metronomic chemotherapy known to have favorable immunogenic effects, which was a deliberate, science-backed choice.

The ADC mirvetuximab is the first drug to demonstrate an overall survival benefit for platinum-resistant ovarian cancer. This groundbreaking result establishes a higher efficacy standard that subsequent therapies will likely need to meet for regulatory approval and clinical adoption, raising the bar for future drug development.

The INTERACT trial showed carboplatin/paclitaxel had similar response rates and PFS to cisplatin/5-FU. It became the standard of care primarily due to its significantly better side effect profile, with lower rates of bone marrow suppression, fatigue, and GI toxicity.