Combination of pembrolizumab and imatinib in a patient with double KIT mutant melanoma: A case report.

RATIONALE

The treatment of metastatic melanoma has been revolutionized in the past decade because of the development of immunotherapies and targeted therapies. Despite these developments, there is still an unmet clinical need for more advanced combination therapies for the subset of patients who remain resistant to immunotherapy or targeted therapy alone. To our knowledge, no reports have been published on combinations of PD-1 blockades and c-KIT inhibitors in melanoma patients. Furthermore, data are limited regarding the safety and efficacy of this combination in patients harboring KIT mutations.

PATIENT CONCERNS AND DIAGNOSIS

We report a case of an 82-year-old female with metastatic melanoma who was found to have double KIT mutations at V559 and N822I.

INTERVENTIONS

She was treated with a combination of c-KIT inhibitor and PD-1 blockade after being resistant to anti-PD-1 monotherapy.

OUTCOMES

Patient developed two episodes of grade 2 liver toxicity requiring treatment breaks followed by a dose reduction. Her transaminitis eventually resolved and patient remained on combination treatment for almost two years with good control of her disease prior to progression.

LESSONS

Treatment options for patients who progress after PD-1 inhibitors are very limited; therefore, there is a high unmet clinical need for this patient population. Combining Imatinib with checkpoint inhibitors may be efficacious in patients with metastatic melanoma and KIT mutations. This novel combination can cause additional toxicities which seem to be overall manageable.