China Watch P260-ASCO take-aways:Physician feedback on IO Chinese trials

Camrelizumab safety profile inlineHemangioma has become a focus for investors recently. We spoke with multiple US PIs with experience in various tumor types, and none had seen this as hemangioma had not shown up in the PD1 safety database. The Chinese PIs we spoke with suggested that hemangioma usually emerges after 2-3 weeks but would disappear in around 4-5 months, regardless of whether patients stay on the drug. Additionally, almost all AEs are grade 1. However, we also learned from Incyte that hemangioma will disappear as the drug is taken off. Additionally, we believe Incyte is conducting further studies to investigate this specific toxicity profile. On the few deaths from the camrelizumab P1 study, we confirmed with PIs and Hengrui executives that all of them were due to disease progression and not related to treatment.

    PD1 response rate lower in melanoma/NSCLC in Chinese patients vs. the USPhysician experts indicated that response rates for melanoma range around 20-25% among Chinese patients, based on their experience, significantly lower than the 30-40% response rates published in various US studies of single agent activities (CFDA has not approved any PD1 combo study in China). We attribute this to two potential drivers: histology and etiology. First, ALM (acral lentiginous melanoma) is the most common type of melanoma among Asians, while the second most common type is mucosal melanoma. These two represent about 70% of the melanoma among Asians but only 5% among Caucasians. Second, it is believed that over-exposure to UV light is a leading cause of melanoma in Caucasians but this might not be the cause in Asians. As for NSCLC, even the patient population that received PD1 is still small, the response rate is obviously lower, according to PIs. As a reminder, EGFR mutation positive patients represent around 45-50% of the patient population among Asians, vs. approximately 10% in the US. Specifically, EGFR mutation positive patients represent 80-90% of non-smokers in Asians. Based on published data, both pembrolizumab and nivolumab have limited activities among EGFR mutation positive NSCLC patients.

    PD1 opportunities could be slightly smaller than previously expected in ChinaWe have learned that response rates appear lower among melanoma, NSCLC and gastric cancer patients in China vs. the US. While these are anecdotal data points, we believe it is prudent to conclude that the PD1 opportunities could be slightly smaller than we previously expected. Additionally, we believe that manufacturers would have to conduct more studies with biomarkers in order to properly demonstrate IO activities in specified patient populations.