Highlighted Studies at
#WCLC26
1️⃣ HARMONi-2
In treatment-naïve, advanced NSCLC with PD-L1 ≥1%, ivonescimab improved PFS (11.1 vs 5.8 months; HR 0.51) and OS (30.8 vs 22.6 months; HR 0.73) compared with pembrolizumab.
This is a genuinely positive trial, but it does not tell the same story for all PD-L1-positive patients. The OS benefit was clear in the ≥50% subgroup, whereas the HR was 0.85 with a confidence interval crossing 1 in the 1–49% subgroup. Moreover, pembrolizumab monotherapy is not the real comparator for most patients in this group; chemo-IO is.
2️⃣ SWOG S1827/MAVERICK
In patients with SCLC who had completed initial treatment and had no brain metastases, MRI surveillance was compared with MRI plus PCI. MRI alone reduced the risk of cognitive failure or death (HR 0.60); grade ≥3 toxicity was 0.8% vs 7.9%. Interim OS and brain metastasis-free survival were not different.
The study does not show that MRI prevents brain metastases more effectively. It shows that adding PCI has so far caused cognitive and serious toxicity without demonstrating a survival benefit. If regular MRI and prompt salvage treatment can be provided, routine PCI is now difficult to justify. Still, it is too early to say that PCI is completely dead before the final OS analysis.
3️⃣ TAISHAN-302
In relapsed SCLC, the B7-H3 ADC Tam-Peli improved OS from 9.4 to 13.3 months versus topotecan (HR 0.46); PFS was 7.4 vs 2.8 months and ORR was 59% vs 10%. Grade ≥3 treatment-related toxicity was also lower.
ARTEMIS-008
In relapsed SCLC, another B7-H3 ADC, Ris-Rez, also outperformed topotecan: OS was 18.5 vs 10.3 months (HR 0.46), PFS was 7.2 vs 3.0 months, and ORR was 58% vs 13%.
Together with TAISHAN-302, this result strongly confirms that B7-H3 is a genuine target in SCLC. However, the median OS figures from the two trials cannot be used to conclude that Ris-Rez is better. The choice between the two ADCs may be determined more by ILD, hematologic toxicity, and ease of administration than by efficacy figures. The efficacy of either agent after tarlatamab maintenance also remains unknown.
5️⃣ EVOKE-03/KEYNOTE-D46
In metastatic NSCLC with PD-L1 ≥50%, sacituzumab govitecan plus pembrolizumab increased ORR compared with pembrolizumab (%56 vs 44%) and numerically prolonged PFS, but the prespecified statistical threshold was not met. OS was 21.5 vs 22.8 months, duration of response was almost identical, and grade ≥3 toxicity was 56% vs 17%.
Adding the ADC shrank tumors in more patients but did not change the natural course of the disease. Considering the similar duration of response, lack of OS benefit, and substantial toxicity, this combination has no place in clinical practice.