Merck's KEYTRUDA: A New Hope for MPM Patients

Merck, known as MSD outside the United States and Canada, has received a positive opinion from the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP) for the use of KEYTRUDA® (pembrolizumab) in combination with chemotherapy as a first-line treatment for adult patients with unresectable non-epithelioid malignant pleural mesothelioma (MPM). This approval, if granted by the European Commission, will provide a new treatment option for patients with this aggressive and rare form of cancer.

MPM is a type of cancer that affects the lining of the lungs and chest wall, typically caused by exposure to asbestos. It is an aggressive disease with a poor prognosis, and current treatment options are limited. The positive CHMP opinion for KEYTRUDA in combination with chemotherapy offers hope for improved patient outcomes.

KEYTRUDA is an anti-PD-1 therapy that works by enhancing the body's immune response against cancer cells. When combined with chemotherapy, KEYTRUDA can potentially amplify the effectiveness of both treatments. Chemotherapy directly attacks cancer cells, while KEYTRUDA helps the immune system recognize and eliminate cancer cells, creating a synergistic effect. This approach could lead to improved progression-free survival (PFS) and overall survival (OS) compared to chemotherapy alone.

The positive CHMP opinion is based on data from the Phase 3 KEYNOTE-789 trial, which showed that treatment with KEYTRUDA in combination with chemotherapy (cisplatin/gemcitabine) significantly improved PFS and OS in patients with unresectable non-epithelioid MPM. Median OS was 18.9 months in the KEYTRUDA arm versus 14.2 months in the control group, while median PFS was 7.2 months versus 6.8 months, respectively.

KEYTRUDA's safety profile, when combined with chemotherapy, has shown promising results in clinical trials. In the Phase 3 KEYNOTE-789 trial, KEYTRUDA plus chemotherapy demonstrated a manageable safety profile, with no new safety signals compared to chemotherapy alone. The most common adverse reactions were fatigue, nausea, alopecia, and anemia. Serious adverse reactions occurred in 37% of patients receiving KEYTRUDA plus chemotherapy, compared to 49% in the chemotherapy alone group.



The approval of KEYTRUDA in combination with chemotherapy for MPM could have significant implications for Merck's market share in the lung cancer treatment landscape. With this approval, Merck expands its immunotherapy portfolio and gains a new indication for KEYTRUDA. This could potentially increase Merck's market share in lung cancer treatments, as KEYTRUDA is now indicated for multiple lung cancer settings, including first-line treatment for NSCLC expressing PD-L1.

In terms of revenue implications, the EU's positive CHMP opinion for KEYTRUDA in MPM opens up a new market for Merck. With approximately 30,000 new cases of mesothelioma worldwide each year, this approval could generate significant revenue. Assuming a price per KEYTRUDA dose similar to its current use in lung cancer (around $15,000), and considering a typical treatment course of 20 doses, the potential revenue per patient could reach $300,000. With a conservative estimate of 10% of eligible patients receiving this treatment, the potential annual revenue could be around $90 million.

The approval of KEYTRUDA in MPM may also influence the competitive dynamics among other cancer immunotherapy treatments. As Merck's anti-PD-1 therapy, KEYTRUDA has already demonstrated success in various cancer types, including melanoma, lung, and breast cancers. The positive EU CHMP opinion for KEYTRUDA in combination with chemotherapy as a first-line treatment for MPM further strengthens its position in the market. This approval expands KEYTRUDA's indications, potentially attracting more patients and healthcare providers, and increasing its market share in the immunotherapy sector. Competitors such as Bristol-Myers Squibb (Opdivo) and AstraZeneca (Imfinzi) may need to respond with clinical trials or marketing strategies to maintain their competitive edge. Additionally, this approval may encourage further research into combination therapies involving immunotherapy and chemotherapy, potentially leading to more innovative treatment options for patients.

In conclusion, Merck's positive EU CHMP opinion for KEYTRUDA in combination with chemotherapy as a first-line treatment for unresectable non-epithelioid MPM offers hope for improved patient outcomes and a new market opportunity for Merck. This approval could have significant implications for Merck's market share, revenue, and the competitive landscape of cancer immunotherapy treatments. As the approval process continues, investors will closely monitor the progress and potential impact on Merck's financial performance.