Keytruda Monotherapy Approved for 2L+ Esophageal Cancer

August 13, 2019

Impact: High

Get insight from inThought Research experts on the recent approval of Keytruda Monotherapy for 2L+ Esophageal cancer:

• Merck has announced that FDA has approved Keytruda (pembrolizumab) as a monotherapy for patients with recurrent locally advanced or metastatic squamous cell carcinoma of the esophagus whose tumors express PD-L1 (Combined Positive Score [CPS] ≥ 10), with disease progression after one or more prior lines of systemic therapy.
  • PD-L1 positivity will be determined by an FDA-approved companion diagnostic.
• The approval is based on data from KEYNOTE-181 and KEYNOTE-180.
• In KEYNOTE-181, the mOS for PD-L1+ esophageal squamous cell carcinoma (ESCC) patients treated with Keytruda was 10.3 months vs. 6.7 months in the chemotherapy arm (HR=0.64; p not provided).
  • The mPFS was 3.2 months for Keytruda treated patients vs. 2.3 months for the chemotherapy arm (HR=0.66, p not provided).
  • An ORR of 22% (CR rate=5%) was observed in Keytruda treated patients compared with 7% (CR rate=1%) in the chemotherapy arm.

inThought Analysis

The number of Keytruda approvals continues to snowball. With this esophageal cancer indication, Keytruda is now approved in 21 oncology indications across 14 cancer types. The approval comes just one day after Merck’s 2Q19 earnings call on which it was announced that Keytruda sales grew to $2.6B for the quarter (up 58% YoY), thus putting it on pace to surpass $10B in sales over the next year.

Of note, the requirement for PD-L1 positivity will limit uptake especially given the fact that no OS benefit was seen in the overall (ITT) -181 population. In that study, out of 628 subjects, only 167 met the PD-L1 CPS criterion. This provides a rough approximation of the size of the patient subset that may be eligible for Keytruda.

Merck is also running a Keytruda/chemotherapy combination trial in 1L esophageal carcinoma (KEYNOTE-590;NCT03189719). Opdivo, tislelizumab (BeiGene), and camrelizumab (Incyte/Jiangsu Hengrui) are also being investigated in various esophageal cancer settings.

Source: Merck Press Release