The phase 2 trial also includes another 59 patients with metastatic CSCC on 3 mg/kg IV cemiplimab every 14 days, as well as 56 patients with metastatic disease assigned to flat-dose 350-mg IV cemiplimab every 21 days.
Treatment side effects
In the phase 1 study, immunotherapy with cemiplimab was far better tolerated than in traditional cancer chemotherapy. There were two grade 3 cases of elevated liver enzymes and one of arthralgia, but no significant fatigue or nausea and no hypothyroidism. However, judging from the cumulative experience accrued with the five PD-1 checkpoint inhibitors already approved for treatment of other cancers, one must be prepared to encounter hypothyroidism and other endocrinopathies, pneumonitis, hepatitis, and rashes.
“The clinician must have a very high index of suspicion for these immune-related adverse events and a low threshold to consult with colleagues in other specialties – pulmonary, endocrine, and medical oncology – for evaluation and management of these possible side effects. I tell all the patients who are on cemiplimab, ‘Any new anything – a slight cough, mild diarrhea – you’re coming in and you’re getting checked,’ ” according to Dr. Migden.
That being said, the majority of immune-related adverse events because of PD-1 inhibitors are mild to moderate. Of the few that reach grade 3 or above, most can be successfully managed by pausing or discontinuing anti–PD-1 therapy coupled with prompt initiation of immunosuppressive therapy, typically with high-dose steroids, he added.