乌鸦传媒

SAN FRANCISCO -- Adding an investigational PD-1 inhibitor to chemotherapy in the neoadjuvant setting significantly improved pathological complete response (pCR) rates for patients with resectable locally advanced esophageal squamous cell carcinoma (ESCC), a randomized phase III trial from China showed.

In an intention-to-treat population, treatment with camrelizumab plus paclitaxel and cisplatin resulted in a pCR rate of 15.4% versus 4.7% for patients who received the chemotherapy doublet alone (OR 3.81, 95% CI 1.48-9.80, P=0.0034), reported Yin Li, MD, PhD, of the Cancer Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College in Beijing, during the Gastrointestinal Cancers Symposium.

The improvement in pCR was even greater -- 28% -- when camrelizumab was added to nab-paclitaxel and cisplatin (OR 8.11, 95% CI 3.28-20.06, P<0.0001).

While the data are continuing to mature for the co-primary endpoint of event-free survival (EFS), as well as overall survival, "neoadjuvant camrelizumab plus chemotherapy may hold promise as a potential standard of care" for locally advanced ESCC, Li said.

Discussant Michael K. Gibson, MD, PhD, of the Vanderbilt-Ingram Cancer Center at Vanderbilt University Medical Center in Nashville, Tennessee, noted that squamous cell carcinoma represents the predominant histologic subtype of esophageal cancer, accounting for 80%-90% of esophageal cancers worldwide (and about 50% in China alone).

He pointed out that the absolute number of cases and deaths were comparable (604,000 cases and 544,000 deaths in 2020), "telling us that this is a formidable disease for which we certainly need more active therapies."

With that in mind, Gibson said the ESCORT-NEO study did provide encouraging data, calling the pCR results "fantastic."

However, "we don't know in squamous cell cancer whether pathological CR rate ... translates into an overall survival benefit," he added. Therefore, he suggested that this approach shouldn't be used "until the second co-primary endpoint is met."

Li explained that the standard approach to treating locally advanced ESCC has traditionally involved either the administration of neoadjuvant chemotherapy or chemoradiotherapy in patients with high-risk tumors. However, post-surgery disease recurrence remains a concern, he noted, and novel multimodality treatment approaches should be explored to overcome failure after surgery for these patients.

He said that camrelizumab has been approved for use in combination with cisplatin and paclitaxel for the first-line treatment of patients with advanced ESCC in China, and that phase II studies have suggested that neoadjuvant chemotherapy combined with immunotherapy -- including camrelizumab -- improved pCR rates.

For this study, a total of 391 Chinese patients were randomized to the study's three arms -- camrelizumab plus nab-paclitaxel and cisplatin (group A), camrelizumab plus paclitaxel and cisplatin (group B), or paclitaxel and cisplatin (group C). Median patient age was 63 years, and the vast majority were men and had an Eastern Cooperative Oncology Group (ECOG) performance status score of 0.

Of groups A, B, and C, 97%, 96.2%, and 94.6%, respectively, completed two cycles of neoadjuvant therapy, and 86.4%, 89.2%, and 79.8% underwent surgery.

Li reported that subgroup analyses showed a pCR benefit with the camrelizumab/nab-paclitaxel/cisplatin regimen versus chemotherapy alone across all subgroups, with a similar trend -- although not as pronounced -- demonstrated with the camrelizumab/paclitaxel/cisplatin regimen.

Major pathologic response rates were 59.1%, 36.2%, and 20.9% for groups A, B, and C, respectively.

The incidence of postoperative complications was 34.2%, 38.8%, and 32% in the three respective groups. During neoadjuvant treatment, the incidence of grade ≥3 treatment-related adverse events was 34.1%, 28.5%, and 28.8%.

Grade ≥3 immune-related adverse events were infrequent, occurring in 4.5% of patients in group A and 3.8% of patients in group B. Grade ≥3 surgical complications occurred in 6.1%, 12.1%, and 6.8% of patients in groups A, B, and C, respectively.

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