When treating refractory kidney cancer, clinicians prioritize regimens offering the most durable initial response. They argue against “saving” effective drugs for later, as disease progression is traumatic for patients and many never successfully receive subsequent lines of therapy. The goal is long-term disease control now, not preserving theoretical future options.

Kaplan-Meier curves from the VICTORIA-1 trial show a steep, immediate drop-off for patients on fulvestrant monotherapy, with ~60% progressing quickly. In contrast, the giredestrant combination arms show a much flatter initial curve, visually demonstrating that a primary benefit is protecting the large subset of patients who would otherwise fail therapy very early.

The widespread use of PARP inhibitors has altered tumor biology in platinum-sensitive ovarian cancer. A recent meta-analysis of heavily pretreated patients, 97% of whom had prior PARP inhibitor exposure, revealed an objective response rate to subsequent therapy of only 17%—far lower than historical expectations, highlighting a critical unmet clinical need.

The modest benefit of PARP inhibitors in metastatic breast cancer, compared to ovarian cancer, is likely due to resistance induced by prior exposure to DNA-damaging agents like anthracyclines. This explains the clinical rationale for moving PARP inhibitors to earlier treatment settings, such as neoadjuvant or adjuvant therapy, before resistance develops.

A patient's time to progression on first-line CDK4/6 inhibitor therapy acts as an informal biomarker. A shorter duration, such as 14 months, is viewed by experts as "not so great" and indicates a degree of underlying endocrine resistance that influences subsequent treatment strategies.

In ROS1-positive NSCLC, starting with older TKIs before newer agents like Repotrectinib dramatically worsens outcomes. Median overall survival has not been reached after 5 years for TKI-naive patients but drops to just 25 months for those pre-treated with another TKI. This starkly quantifies the critical importance of using the most effective treatment first.

The long-standing platinum doublet backbone for frontline SCLC may soon be challenged. The high efficacy of novel agents like antibody-drug conjugates and bispecific antibodies in later lines is prompting trials that consider moving them into the first-line setting, a strategy previously considered "unthinkable."

The presence of heterogeneous resistance mutations, some of which may be below detection limits, suggests a new strategy. Using a potent, broad-spectrum combination therapy upfront in the second-line setting, rather than sequential monotherapies, could eradicate more resistant clones and give patients a better chance at long-term survival or even a cure.

New CDK inhibitors that also target CDK2 show great activity in models resistant to current CDK4/6 agents. Instead of being reserved for later use, they are already being tested in frontline trials. The strategy, similar to that of ALK inhibitors in lung cancer, is that using the best drug first may prevent or significantly delay the onset of resistance.