China's First DLL3/CD3 Bispecific T-Cell Engager (Tarlatamab) Now at Jiahui

SHANGHAI — Tarlatamab (塔拉妥单抗, brand name Imdelltra / 安泰适®) is the first and only bispecific T-cell engager (BiTE®) approved in China that targets both DLL3 and CD3. It was first approved in the United States in May 2024. In April 2026, Tarlatamab received marketing authorization in China, and it is now officially available at the Jiahui International Cancer Center in Shanghai.

A New Treatment Option for Extensive-Stage Small Cell Lung Cancer

According to data published in the Chinese Journal of Oncology, lung cancer is the most commonly diagnosed malignancy in China. In 2024, an estimated 1.1759 million new lung cancer cases were diagnosed nationwide, and small cell lung cancer (SCLC) accounts for approximately 13–15% of all lung cancers.

SCLC is a highly aggressive tumor that grows rapidly, metastasizes early, and has a poor prognosis. Roughly two-thirds of patients are diagnosed at extensive-stage disease. Survival rates remain grim: five-year overall survival after standard therapy is less than 10%.

First-line platinum-based chemotherapy combined with immunotherapy is the current standard initial treatment. Yet most patients relapse within a short period, and effective second-line options are limited. Tarlatamab addresses this unmet need in the extensive-stage SCLC population.

Approved Indications

Tarlatamab is currently approved in China for adult patients with extensive-stage small cell lung cancer:

• Who have failed at least two prior lines of systemic therapy, including platinum-based chemotherapy; or
• Who have failed one prior line of systemic therapy, including platinum-based chemotherapy.

Jiahui oncology physicians will evaluate each patient's prior treatment history, disease burden, and overall condition to determine whether Tarlatamab is appropriate.

How Tarlatamab Works: Redirecting T Cells Against Tumor Cells

Tarlatamab is a bispecific antibody that simultaneously binds to DLL3 expressed on tumor cells and CD3 expressed on T cells. By bringing T cells into direct contact with cancer cells, it activates the T cells, promotes the release of inflammatory mediators, and induces lysis of DLL3-expressing cells.

Put simply, Tarlatamab recruits the patient's own immune cells to the tumor and redirects them to recognize and destroy SCLC cells that carry DLL3 on their surface.

Key Clinical Evidence: DeLLphi Studies

The approval of Tarlatamab was supported by the global phase 2 DeLLphi-301 study and the Chinese phase 2 DeLLphi-307 study, as well as the landmark phase 3 DeLLphi-304 trial.

DeLLphi-301: Efficacy in Heavily Pretreated Disease

In DeLLphi-301, patients with recurrent or refractory SCLC after at least two prior lines of therapy received Tarlatamab. Among Asian patients, the objective response rate (ORR) reached 46.3%, and the 10 mg dose showed a median progression-free survival (PFS) of 5.4 months. The safety profile was manageable overall.

DeLLphi-307: Confirmation in Chinese Patients

DeLLphi-307 was a prospective, single-arm, multicenter phase 2 study focused on Chinese patients with third-line or later SCLC. Results from 31 Chinese patients were consistent with the global DeLLphi-301 data, supporting the applicability of Tarlatamab in China.

DeLLphi-304: Landmark Phase 3 Survival Benefit

The DeLLphi-304 phase 3 trial randomized 509 patients with extensive-stage SCLC that had progressed after first-line platinum-based chemotherapy with or without anti-PD-(L)1 therapy. The results, published in the New England Journal of Medicine, showed:

• Median overall survival (OS): 13.6 months with Tarlatamab versus 8.3 months with standard chemotherapy (hazard ratio 0.60, P<0.001), representing a 40% reduction in the risk of death.
• Median progression-free survival (PFS): 4.2 months with Tarlatamab versus 3.7 months with chemotherapy (hazard ratio 0.71).
• Safety: Grade ≥3 adverse events occurred in 27% of Tarlatamab-treated patients compared with 62% of chemotherapy-treated patients. Treatment discontinuation due to adverse events was lower in the Tarlatamab group (3% vs 6%).

The most common adverse reaction was cytokine release syndrome (CRS), which was mostly grade 1–2 and typically occurred after the first dose. CRS is manageable with standard supportive care and monitoring.

A Milestone in Chinese SCLC Care

The approval and availability of Tarlatamab in China mark a meaningful step forward for patients with extensive-stage SCLC. It introduces a fundamentally different mechanism of action compared with chemotherapy, providing a new standard-of-care option after progression on initial therapy.

At Jiahui International Cancer Center, this addition supports the broader goal of bringing globally innovative therapies to Chinese and international patients without requiring travel abroad.

Accessing Tarlatamab at Jiahui

Patients or referring physicians seeking information about Tarlatamab at Jiahui International Cancer Center can request a consultation. The oncology team reviews pathology, imaging, and prior treatment records to assess eligibility and discuss benefits, risks, and monitoring requirements.

References

1. Xinhuanet Health. Tarlatamab approved in China for SCLC. 2026. https://www3.xinhuanet.com/health/20260529/8f112ba1cc38490ab63d5532b9795c17/c.html
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