Can Imdeltra cause double vision and unilateral periorbital swelling, and should it be stopped immediately with urgent ophthalmology evaluation?

Double Vision and Unilateral Eye Swelling with Imdeltra

Imdeltra (tarlatamab) does not list double vision or unilateral periorbital swelling as recognized adverse effects in its FDA labeling, and these symptoms warrant immediate urgent ophthalmology evaluation to rule out serious neurologic complications, particularly given Imdeltra's known risk of immune effector cell-associated neurotoxicity syndrome (ICANS) which can present with neurologic symptoms. 1

Imdeltra's Known Ocular and Neurologic Risks

Neurologic Toxicity Including ICANS

• Imdeltra carries a significant risk of life-threatening neurologic toxicity, occurring in 65% of patients, with Grade 3 or higher events in 7% of patients 1
• ICANS specifically occurred in 10% of Imdeltra-treated patients, with manifestations including muscular weakness (3.2%), cognitive disorder (0.6%), aphasia (0.6%), depressed level of consciousness (0.4%), seizures (0.4%), and encephalopathy (0.4%) 1
• The median time to onset of ICANS was 16 days from first dose (range: 1 to 862 days), meaning it can occur several weeks after administration 1
• ICANS can occur concurrent with cytokine release syndrome (CRS), following resolution of CRS, or in the absence of CRS 1

Absence of Documented Ocular Swelling

• The FDA labeling for Imdeltra does not specifically mention periorbital edema or unilateral eye swelling as adverse effects 1
• The most common adverse reactions include CRS (57%), neurologic toxicity (65%), and cytopenias, but not ocular swelling 1

Critical Clinical Approach

Immediate Actions Required

• At the first sign of neurologic symptoms (which could include diplopia), immediately withhold Imdeltra infusion and evaluate the patient 1
• Urgent ophthalmology consultation is mandatory to assess for:
  • Cranial nerve palsies (particularly CN III, IV, or VI) that could cause diplopia
  • Orbital pathology causing mass effect
  • Signs of increased intracranial pressure
  • Inflammatory or infectious orbital processes 1

Neurologic Evaluation

• Consider neurology consultation to rule out ICANS and other neurologic causes of diplopia 1
• Perform comprehensive neurologic examination looking for other signs of ICANS including confusional state, depressed level of consciousness, disorientation, somnolence, or lethargy 1
• Rule out other causes of neurologic symptoms before attributing to Imdeltra 1

Management Algorithm Based on Severity

If ICANS is Suspected (Grade 1-2)

• Withhold Imdeltra until ICANS resolves, then resume at next scheduled dose 1
• Provide supportive care 1
• For Grade 2: Consider dexamethasone 8-10 mg oral or IV, repeatable every 12 hours if symptoms worsen 1
• Monitor neurologic symptoms continuously and consider neurology consultation 1

If Severe Neurologic Toxicity (Grade 3-4)

• For Grade 3: Withhold Imdeltra until event resolves; for recurrent Grade 3 or any Grade 4, permanently discontinue 1
• Intensive monitoring (ICU care) may be required 1
• Administer dexamethasone 8 mg IV every 8 hours up to 3 doses 1

Important Caveats

Differential Diagnosis Considerations

• While unilateral periorbital swelling is not a documented Imdeltra side effect, it could represent:
  • Localized infection (given immunosuppressive effects of therapy) 2
  • Orbital inflammatory process
  • Vascular event
  • Coincidental unrelated pathology 3

Monitoring Requirements

• Patients receiving Imdeltra are at risk of neurologic adverse reactions resulting in depressed level of consciousness and should refrain from driving until neurologic symptoms resolve 1
• Close monitoring for signs and symptoms of neurologic toxicity during treatment is essential 1

Documentation Note

• The provided evidence regarding dupilumab-related ocular surface disorders 4 is not applicable to Imdeltra (tarlatamab), as these are entirely different medications with different mechanisms and side effect profiles