A phase III TAISHAN-302 trial reported that Tam-Peli, an anti–B7-H3 antibody-drug conjugate, cut the risk of death by 54% versus topotecan in patients with relapsed small-cell lung cancer. The randomized comparison targets a long-standing treatment gap after platinum-based chemotherapy failure. These results strengthen the case for B7-H3 as an ADC target in SCLC and place Tam-Peli head-to-head against a commonly used second-line option. Clinicians typically need more effective regimens in a disease area where post-progression outcomes remain limited. While additional efficacy endpoints and safety detail will determine how quickly practice shifts, the magnitude of the survival effect is the central development from the dataset.