@Philip20130410 刚才给你回复时，雪球只显示了我写的的上半部，下半部都没了。重新写了下专门发了个贴子，大家可以一起讨论。
看了$再生元制药(REGN)$ 在ASCO刚披露的这个NSCLC数据的背景。 21个病人，都是一线化疗失败的。关于PDL1表达, 其中11人 PDL1< 1%, 3人> 50%. 另外7个人没有仔细说明，我假设PDL1表达在1-49%之间。网页链接
为了找到合适的和Keytruda类似病人情况的临床结果对比，我花了不少点时间把keytruda公开的NSCLC数据找到了。关于NSCLC主要有四个重要的临床试验，KEYNOTE001， 010， 021，189.
keynote001是第一个临床，其中包括200人左右的NSCLC病人, 包括之前一线治疗和未治疗的。发表的文章在此。网页链接 其中提到
可以看出PDL1的表达对ORR的影响很大。在之前化疗过的人群中，如果PDL1的表达在1-49%之间，ORR是16%， 如果表达低于1%， ORR是9%。
KEYNOTE010 是看PDL1表达>1%的NSCLC病人和紫杉醇对比的临床结果。结果显示如果PDL1表达>50%， ORR达到惊人的89%。
Patients enrolled in KEYNOTE-010 came from 24 countries; they had advanced NSCLC with a PD-L1 tumor proportion score (TPS) of at least 1% and had been previously treated with at least one line of chemotherapy. The updated data showed that median overall survival was 8.6 months with docetaxel, compared with 10.5 months (hazard ratio [HR] = 0.72) with lower-dose pembrolizumab and 13.4 months (HR = 0.60) with higher-dose pembrolizumab。 Remaining analyses were restricted to the 47 patients who completed the entire planned 2 years of pembrolizumab at either dose and then stopped therapy. Fully 66% of these patients had tumors with at least 50% PD-L1 positivity, compared with 42% of all patients on the trial given pembrolizumab. In this group, the overall response rate was 89%, and the clinical benefit rate was 100%.
KEYNOTE021和189，是对比keytruda+chemo 和chemo在NSCLC的头对头。数据非常强大。分别看PDL1表达<1%, 1-49%，>50%的三组病人，全部显示临床意义。
patients whose tumors were negative for PD-L1 (HR=0.59 [95% CI, 0.38-0.92]); patients whose tumors had PD-L1 tumor proportion scores (TPS) of 1-49 percent (HR=0.55 [95% CI, 0.34-0.90]); and patients who had a TPS of greater than or equal to 50 percent (HR=0.42 [95% CI, 0.26-0.68]).
回过头看REGN的这个数据，Best response by central independent review was 0 complete response (CR), 6 partial response (PR), 6 stable disease (SD) or non-CR/progressive disease (PD), and 9 PD. Overall response rate (ORR = CR + PR) was 28.6% (n = 6/21). 如果去掉那三个高表达病人（ 假设都有response），剩下只有三个response， ORR=17% (N=3/18). 和keytruda在KEYNOTE001的结果类似。
总体看，REGN的PD1在那个皮肤癌，和这个肺癌上的早期数据还是不错。可惜比keytruda晚了三年多。现在keytruda+chemo已经变成了非小细胞肺癌的standard of care。 REGN的pipeline里还有一个和keytruda的头对头临床，证明管理层还是很有信心，期待那个结果。
我对REGN的这个pd1在肺癌上谨慎看好，但需要一步一步来。