There exists a dilemma in the treatment of microsatellite stability (MSS) metastatic colorectal cancer (mCRC) owing to limited therapeutic options. Based on the promising results of the REGONIVO trial, combination of anti-PD-1 and regorafenib could be applicable for this kind of patients. Here we first report a case of an MSS mCRC patient who received sinitilimab plus regorafenib as third-line treatment and suffered severe multisystem treatment-related adverse events including Grade 3 myocarditis, myositis, myasthenia gravis, dermatitis, hepatitis, etc. Fortunately, all these adverse events were reversed with administration of corticosteroids. Though evidence of tumor shrinkage was not found, CEA levels markedly decreased. Therefore, anti-PD-1 plus regorafenib might be optional for the MSS mCRC patients which requires special caution in the clinical practice.
Keywords: MSS metastatic colorectal cancer; adverse events; anti-PD-1; case report; regorafenib; sinitilimab.
Lay abstract There exists a dilemma in the treatment of metastatic colorectal cancer (mCRC) owing to limited therapeutic options. Based on the results of clinical trials, combination of anti-PD-1 and regorafenib is promising for these patients. Here we first report a case of an mCRC patient who received sinitilimab plus regorafenib as third-line treatment and suffered severe multisystem treatment-related adverse events including grade 3 myocarditis, myositis, myasthenia gravis, dermatitis, hepatitis, etc. Fortunately, all these adverse events were reversed with administration of corticosteroids. Though evidence of tumor shrinkage was not found, serum tumor marker level markedly decreased. Therefore, anti-PD-1 plus regorafenib might be optional for the mCRC patients which requires special caution in the clinical practice.