IMDELLTRA

What it is

Imdelltra is a bispecific DLL3-directed CD3 T-cell engager that binds to DLL3 expressed on the surface of tumour cells and CD3 expressed on the surface of T-cells. It is supplied as a lyophilised powder for injection with intravenous (IV) solution stabiliser. The product is subject to additional monitoring in Australia to allow quick identification of new safety information.

Approved indications

— Treatment of adult patients with extensive-stage small cell lung cancer (ES-SCLC) with disease progression on or after platinum-based chemotherapy.

Dosing overview

Imdelltra should be administered according to a step-up dosing schedule to reduce the incidence and severity of cytokine release syndrome (CRS). The step-up schedule begins with 1 mg on Cycle 1 Day 1, followed by 10 mg on Day 8, then 10 mg on Day 15. From Cycle 2 onwards, 10 mg is administered on Days 1 and 15 of each cycle. After step-up dosing, Imdelltra is administered biweekly (every 2 weeks) until disease progression or unacceptable toxicity. Each infusion is administered as an intravenous infusion over one hour.

Key safety warnings

Cytokine release syndrome (CRS), including serious or life-threatening reactions, can occur in patients receiving Imdelltra. CRS may be associated with symptoms including pyrexia, hypotension, hypoxia, fatigue, tachycardia, headache, chills, nausea, and vomiting, and potentially life-threatening complications may include cardiac dysfunction, acute respiratory distress syndrome, neurologic toxicity, renal and/or hepatic failure, and disseminated intravascular coagulation. Neurologic toxicity, including immune effector cell-associated neurotoxicity syndrome (ICANS), including serious or life-threatening reactions, can occur in patients receiving Imdelltra. Adverse events that may be associated with ICANS include headache, encephalopathy, confusion, delirium, seizure, ataxia, neurotoxicity, and tremor. Imdelltra can cause cytopenias including neutropenia (12% including 6% Grade 3 or 4), thrombocytopenia (33% including 3.2% Grade 3 or 4), and anaemia (58% including 5% Grade 3 or 4), with febrile neutropenia occurring in 0.5% of patients. Imdelltra can cause serious infections, including life-threatening and fatal infections, with infections occurring in 41% of patients (13% Grade 3 or 4), with the most frequent being COVID-19 (9%), urinary tract infection (10%), pneumonia (9%), respiratory tract infection (3.2%), and Candida infection (3.2%). Imdelltra can cause hepatotoxicity, with elevated ALT occurring in 42% (2.1% Grade 3 or 4), elevated AST in 44% (3.2% Grade 3 or 4), and elevated bilirubin in 15% (1.6% Grade 3 or 4).

Contraindications

Imdelltra is contraindicated in patients with hypersensitivity to tarlatamab or to any of the excipients.

Regulatory history

Imdelltra was first included in the Australian Register of Therapeutic Goods on 26 June 2025. The TGA granted provisional approval for Imdelltra for adult patients with extensive-stage small cell lung cancer (ES-SCLC) with disease progression on or after platinum-based chemotherapy, based on overall response rate and duration of response from a single-arm trial, with continued approval dependent on verification of benefit in confirmatory trials.