A B7-H3 antibody-drug conjugate cut the risk of death by half in relapsed small-cell lung cancer

Design

Phase 3, multicentre, open-label randomised trial (interim analysis)

Population

451 patients in China with small-cell lung cancer progressing after first-line platinum

Primary outcome

Overall survival

Effect

Median 13.3 vs 9.4 months; HR 0.46 (0.35–0.62); grade ≥3 events 55.4% vs 77.9%

TAISHAN-302, an open-label phase 3 trial in China published in NEJM on 12 September, randomised 451 patients with small-cell lung cancer progressing after first-line platinum to tambotatug pelitecan, an antibody-drug conjugate directed at B7-H3, or topotecan. This was a prespecified interim analysis.

Median overall survival was 13.3 months against 9.4 months (hazard ratio 0.46). Progression-free survival was 7.4 against 2.8 months, and objective responses 59% against 10%. Grade 3 or worse adverse events were less frequent with the conjugate (55% vs 78%).

Second-line small-cell lung cancer has had few options beyond topotecan, which offers modest benefit with significant marrow toxicity. A drug that improves survival and is better tolerated would change that line of therapy.

The trial was conducted entirely in China, investigator-assessed and open-label, and the drug's regulatory status outside China is not established by this report. Availability in India is unknown.

• Consider referring patients with relapsed small-cell lung cancer for trials of B7-H3-directed agents where available.
• Topotecan remains the standard second-line option until regulatory decisions are made.
• Grade 3 or worse toxicity was lower with the conjugate than with topotecan.
• Overall survival data are from an interim analysis and may change with longer follow-up.

Why it matters

It is a survival gain in a setting where options beyond topotecan have been few.

Don't overread it

This is an interim analysis of an open-label trial in China only; approval and availability elsewhere are not established.

The statistics, in plain English

A hazard ratio of 0.46 (95% CI 0.35 to 0.62) means about half the risk of death at any point. The upper limit of the conjugate's median survival could not yet be estimated because many patients were still alive, which is common at interim analysis.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.