Tam-Peli Extends Survival in Relapsed Small Cell Lung Cancer

Tambotatug pelitecan (tam-peli) significantly improved overall survival (OS) in patients with relapsed small cell lung cancer (SCLC) previously treated with platinum-based chemotherapy, according to results from the phase 3 TAISHAN-302 trial presented at the International Association for the Study of Lung Cancer 2026 World Conference on Lung Cancer and published in the New England Journal of Medicine.^1,2

Median OS was 13.3 months with tam-peli compared with 9.4 months with topotecan, translating to a 54% reduction in the risk of death (HR, 0.46; 95% CI, 0.35-0.62; P <.0001). The median follow-up for OS was 9.2 months and 9.5 months in the respective groups.¹

Progression-free survival (PFS) was also significantly longer with tam-peli, at 7.4 months versus 2.8 months with topotecan (HR, 0.29; 95% CI, 0.23-0.37; P <.0001), representing a 71% reduction in the risk of disease progression or death.1 The confirmed objective response rate was 59.1% versus 9.7%, respectively (P <.0001). All confirmed responses were partial responses, with no complete responses reported in either group. Disease control rates were 91.1% and 50.9%, respectively. Median duration of response was 6.3 months with tam-peli and 7.8 months with topotecan, while median time to response was 1.5 months and 2.6 months, respectively.^1,3

In patients with baseline brain metastases, an exploratory analysis showed median intracranial PFS of 6.1 months with tam-peli versus 4.2 months with topotecan (HR, 0.43; 95% CI, 0.27-0.68; nominal P =.0002). Intracranial confirmed response rates were 32.4% and 2.9%, respectively.^1,3 Overall survival benefits were generally consistent across prespecified subgroups, including patients with and without brain or liver metastases and those with chemotherapy-free intervals of less than 90 days or at least 90 days.¹

“The second positive phase III trial for Tam-Peli, TAISHAN-302, reinforces our confidence in its potential to improve outcomes for people with cancer,” Levi Garraway, MD, PhD, Roche’s chief medical officer and head of global product development, stated in a news release.² “These data demonstrate clinically meaningful survival and response rate improvements in an aggressive and hard-to-treat disease, supporting our plans to initiate global phase III trials quickly.”

Safety of Tam-Peli

The incidence of grade 3 or higher treatment-related adverse events (TRAEs) was 46.4% with tam-peli and 74.7% with topotecan. Serious treatment-related adverse events occurred in 25.9% and 36.4% of patients, respectively. TRAEs leading to treatment discontinuation occurred in 5.8% of patients receiving tam-peli and 2.8% receiving topotecan. No treatment-related deaths occurred in the tam-peli group vs 1 treatment-related death in the control arm.³

The overall incidence of grade 3 or higher adverse events was 55.4% with tam-peli compared with 77.9% with topotecan.¹ Treatment-emergent interstitial lung disease or pneumonitis occurred in 4.9% of patients in the tam-peli arm and 1.4% in the topotecan arm. Grade 3 events occurred in 0.9% of patients in each group, with no grade 4 or 5 events reported.^1,2

TAISHAN-302 Design

TAISHAN-302 (NCT06612151) was a randomized, open-label phase 3 study that enrolled 451 patients at 85 sites in China. Participants had histologically or cytologically confirmed SCLC that had progressed following 1 prior line of platinum-based chemotherapy, with or without a prior programmed cell death ligand 1 (PD-L1) inhibitor. Patients were required to have at least 1 measurable lesion and an Eastern Cooperative Oncology Group performance status of 0 or 1.^1,2

Patients were randomly assigned 1:1 to tam-peli at 2.0 mg/kg intravenously on day 1 of each 21-day cycle, with a maximum dose of 200 mg, or topotecan at 1.2 mg/m² on days 1 through 5 of each 21-day cycle. Treatment continued until disease progression or unacceptable toxicity, and crossover between treatment groups was not permitted.^1,2

Overall survival was the primary end point. Key secondary end points included investigator-assessed PFS and objective response rate, with disease control rate, duration of response, time to response, safety, pharmacokinetics, and immunogenicity also evaluated.¹

Tam-peli is an investigational B7-H3-targeted antibody-drug conjugate that uses MediLink Therapeutics’ Tumour Microenvironment-Activatable Linker platform. The agent combines a B7-H3-directed monoclonal antibody with a topoisomerase 1 inhibitor payload.²

Roche holds development, manufacturing, and commercialization rights for tam-peli outside mainland China, Hong Kong, and Macau and has stated that it plans to initiate global phase 3 studies across multiple solid tumors.²

REFERENCES

1. Zhao Y, Liu H, Meng X, et al; TAISHAN-302 Investigators. Tambotatug pelitecan in small-cell lung cancer after platinum-based therapy. N Engl J Med. Published September 12, 2026. doi:10.1056/NEJMoa2610229.

2. Roche. Roche’s collaborator MediLink announces phase III data for Tam-Peli showing significantly improved overall survival in Chinese patient population with relapsed small-cell lung cancer. Published September 13, 2026. https://tinyurl.com/yt9d2297

3. Zhang L, Zhao Y, Liu H, et al. Tam-Peli, an anti-B7-H3 antibody-drug conjugate, versus topotecan in relapsed SCLC: a randomized, open-label, phase 3 study (TAISHAN-302). Presented at: International Association for the Study of Lung Cancer 2026 World Conference on Lung Cancer; September 12-15, 2026; Seoul, South Korea. Abstract PL02.03