Late-breaking results selected for presentation during a Presidential Symposium session and an official Press Briefing at the European Society for Medical Oncology Congress 2024 and simultaneous publication in the New England Journal of Medicine

KEYTRUDA is the first and only immunotherapy-based regimen to show a statistically significant and clinically meaningful improvement in overall survival as pre-operative (neoadjuvant) treatment with chemotherapy and then as a single agent after surgery (adjuvant) compared to pre-operative chemotherapy in patients with high-risk early-stage TNBC

KEYNOTE-522 marks the fourth study of a KEYTRUDA-based regimen in an earlier stage of cancer to demonstrate an OS benefit

RAHWAY, NJ, USA I September 15, 2024 I Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced the first-time presentation of overall survival (OS) results from the Phase 3 KEYNOTE-522 trial evaluating KEYTRUDA® (pembrolizumab), Merck’s anti-PD-1 therapy, in combination with chemotherapy as pre-operative (neoadjuvant) treatment and then continuing as a single agent after surgery (adjuvant) for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC). After a median follow-up of 75.1 months (range, 65.9-84.0), the KEYTRUDA regimen significantly improved OS, a key secondary endpoint, reducing the risk of death by 34% (HR=0.66 [95% CI, 0.50-0.87]; p=0.0015) in patients with high-risk early-stage TNBC compared to the chemotherapy-placebo regimen (placebo plus chemotherapy followed by placebo after surgery). The five-year OS rate was 86.6% (95% CI, 84.0-88.8) for patients who received the KEYTRUDA regimen versus 81.7% (95% CI, 77.5-85.2) for patients who received the chemotherapy-placebo regimen. Median OS was not reached in either group. The safety profile of KEYTRUDA was consistent with that observed in previously reported studies with no new safety signals observed.

These late-breaking data are being presented for the first time today during a Presidential Symposium session at the European Society for Medical Oncology (ESMO) Congress 2024 (presentation #LBA4) and were selected for an official Press Briefing. These data are also being simultaneously published in the New England Journal of Medicine. KEYTRUDA is the first and only immunotherapy-based regimen to show a statistically significant and clinically meaningful improvement in OS as neoadjuvant treatment with chemotherapy and then continued as a single agent as adjuvant treatment compared to placebo plus chemotherapy followed by placebo after surgery in patients with high-risk early-stage TNBC.

In pre-specified exploratory subgroup analyses of OS, the benefit of the KEYTRUDA regimen was consistent across pre-specified subgroups, including those defined by PD-L1 expression, tumor size and nodal status.

“These impactful overall survival results add to the previously reported pathological complete response and event-free survival data from the KEYNOTE-522 trial,” said Dr. Peter Schmid, lead, Centre for Experimental Cancer Medicine, Barts Cancer Institute in London, England. “In this study, pembrolizumab plus chemotherapy as neoadjuvant treatment and continued as a single agent after surgery reduced the risk of death by more than one-third compared to neoadjuvant chemotherapy, reinforcing the important role this regimen plays in the treatment of high-risk early-stage triple-negative breast cancer.”

“KEYTRUDA is the first and only immunotherapy-based regimen to show a statistically significant and clinically meaningful improvement in overall survival compared to chemotherapy alone in patients with high-risk early-stage triple-negative breast cancer,” said Dr. Gursel Aktan, vice president, global clinical development, Merck Research Laboratories. “This is an important milestone and represents the fourth KEYTRUDA study to demonstrate a significant overall survival benefit in an earlier stage of cancer, highlighting our efforts to help extend the lives of patients with certain cancers across different stages of disease.”

KEYNOTE-522 is one of four Phase 3 studies of a KEYTRUDA-based regimen in an earlier stage of cancer to demonstrate an OS benefit, including KEYNOTE-A18 in newly diagnosed, high-risk locally advanced cervical cancer (as treatment with chemoradiotherapy, compared to chemoradiotherapy), KEYNOTE-671 in resectable stage II, IIIA or IIIB non-small cell lung cancer (as treatment with chemotherapy before surgery and then as a single agent after surgery, compared to pre-operative chemotherapy) and KEYNOTE-564 in renal cell carcinoma for patients at intermediate-high or high risk of recurrence following nephrectomy, or following nephrectomy and resection of metastatic lesions (compared to placebo).

As previously announced, the KEYNOTE-522 trial met its dual primary endpoints of pCR and event-free survival (EFS) at earlier interim analyses. Based on these results, KEYTRUDA is approved in the U.S. in combination with chemotherapy as neoadjuvant treatment and then continued as a single agent as adjuvant treatment after surgery for the treatment of patients with high-risk early-stage TNBC. KEYNOTE-522 also supported regulatory approvals for certain patients with TNBC in Europe, Japan and other countries globally.

As announced, data spanning more than 20 types of cancer are being presented from Merck’s broad oncology portfolio and investigational pipeline at the ESMO Congress 2024.

Study design and additional data from KEYNOTE-522

KEYNOTE-522 is a Phase 3, randomized, double-blind trial (ClinicalTrials.gov, NCT03036488) evaluating KEYTRUDAin combination with chemotherapy as pre-operative (neoadjuvant) treatment and then continuing as a single agent after surgery (adjuvant) compared to placebo plus chemotherapy as neoadjuvant treatment followed by placebo as adjuvant treatment in patients with high-risk early-stage TNBC (stage T1c N1-2 or T2-4 N0-2 per AJCC). The dual primary endpoints were pCR rate, defined as pathological stage ypT0/Tis ypN0 at the time of definitive surgery, and EFS, defined as the time from randomization to the time of first occurrence of either disease progression that precluded definitive surgery, a local/distant recurrence, a second primary cancer or death from any cause. A key secondary endpoint was OS. The study enrolled 1,174 patients who were randomized 2:1 to receive either:

  • The KEYTRUDA regimen: KEYTRUDA plus chemotherapy (paclitaxel and carboplatin), followed by KEYTRUDA plus chemotherapy (cyclophosphamide and either doxorubicin or epirubicin) as neoadjuvant therapy prior to surgery, followed by KEYTRUDA monotherapy as adjuvant therapy post-surgery (n=784), or;
  • The chemotherapy-placebo regimen: Placebo plus chemotherapy (paclitaxel and carboplatin), followed by placebo plus chemotherapy (cyclophosphamide and either doxorubicin or epirubicin) as neoadjuvant therapy prior to surgery, followed by placebo monotherapy as adjuvant therapy post-surgery (n=390).

After a median follow-up of 75.1 months (range, 65.9-84.0), the KEYTRUDA regimen reduced the risk of EFS events by 35% (HR=0.65 [95% CI, 0.51-0.83]) in patients with high-risk early-stage TNBC compared to the chemotherapy-placebo regimen. The five-year EFS rate was 81.2% (95% CI, 78.3-83.8) for those treated with the KEYTRUDA regimen compared to 72.2% (95% CI, 67.4-76.4) for those treated with the chemotherapy-placebo regimen.

At this analysis, treatment-related adverse events (TRAEs) were examined in the neoadjuvant phase, the adjuvant phase and the combined phases. TRAEs in the neoadjuvant phase have been previously reported. At the time of this data cutoff, no patients were still receiving protocol treatment. For the combined neoadjuvant and adjuvant phases, TRAEs occurred in 98.9% of patients receiving the KEYTRUDA regimen (n=783) and 99.7% of patients receiving the chemotherapy-placebo regimen (n=389); Grade 3-5 TRAEs occurred in 82.4% versus 78.7%, respectively. TRAEs led to death in 0.5% of patients receiving the KEYTRUDA regimen (n=4) and 0.3% of patients receiving the chemotherapy-placebo regimen (n=1). No new safety concerns were identified.

Immune-mediated adverse events (AEs) and infusion reactions of any grade in the combined neoadjuvant and adjuvant phases occurred in 44.8% of patients receiving the KEYTRUDA regimen and 22.9% of patients receiving the chemotherapy-placebo regimen. The most common of these events (occurring in ≥10% of patients) were infusion reactions (18.0%) and hypothyroidism (15.1%) in patients receiving the KEYTRUDA regimen and infusion reactions (11.6%) in patients receiving the chemotherapy-placebo regimen. Immune-mediated AEs led to death in 0.3% of patients receiving the KEYTRUDA regimen (n=2) and no patients receiving the chemotherapy-placebo regimen.

About triple-negative breast cancer (TNBC)

Triple-negative breast cancer is the most aggressive type of breast cancer, which has the highest risk of recurrence within the first five years after diagnosis and is associated with worse outcomes compared to other forms of breast cancer. Approximately 10-15% of patients with breast cancer are diagnosed with TNBC. While some breast cancers may test positive for estrogen receptors, progesterone receptors or overexpression of human epidermal growth factor receptor 2 (HER2), TNBC tests negative for all three. Triple-negative breast cancer tends to be more common in people who are younger than 40 years of age, who are Black or who have a BRCA1 mutation.

About Merck’s research in women’s cancers

Merck is advancing research aimed at expanding treatment options for certain breast and gynecologic (ovarian, cervical and endometrial) cancers, with a goal of improving outcomes for more patients affected by these diseases. Breast cancer and gynecological cancers are the first and second most commonly occurring cancer types among women worldwide, respectively, and Merck aims to give patients facing these devastating diseases options. With more than 20 clinical trials in more than 18,000 patients around the world, Merck is driving innovative research to purposefully advance standards of care in women’s cancers. Merck’s research efforts include trials focused on evaluating its medicines in earlier stages, as well as identifying novel mechanisms and new combinations with these treatments. Merck is working to develop a portfolio and pipeline to address the impact of women’s cancers on patients, their families and communities globally.

About Merck’s early-stage cancer clinical program

Finding cancer at an earlier stage may give patients a greater chance of long-term survival. Many cancers are considered most treatable and potentially curable in their earliest stage of disease. Building on the strong understanding of the role of KEYTRUDA in later-stage cancers, Merck is evaluating our portfolio of medicines and pipeline candidates in earlier disease states, with more than 30 ongoing registrational studies across multiple types of cancer.

About KEYTRUDA® (pembrolizumab) injection, 100 mg

KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.

Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient’s likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.

Selected KEYTRUDA® (pembrolizumab) Indications in the U.S.

Triple-Negative Breast Cancer

KEYTRUDA is indicated for the treatment of patients with high-risk early-stage triple-negative breast cancer (TNBC) in combination with chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.

KEYTRUDA, in combination with chemotherapy, is indicated for the treatment of patients with locally recurrent unresectable or metastatic TNBC whose tumors express PD-L1 (CPS ≥10) as determined by an FDA-approved test.

Melanoma

KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic melanoma.

KEYTRUDA is indicated for the adjuvant treatment of adult and pediatric (12 years and older) patients with Stage IIB, IIC, or III melanoma following complete resection.

Non-Small Cell Lung Cancer

KEYTRUDA, in combination with pemetrexed and platinum chemotherapy, is indicated for the first-line treatment of patients with metastatic nonsquamous non-small cell lung cancer (NSCLC), with no EGFR or ALK genomic tumor aberrations.

KEYTRUDA, in combination with carboplatin and either paclitaxel or paclitaxel protein-bound, is indicated for the first-line treatment of patients with metastatic squamous NSCLC.

KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with NSCLC expressing PD-L1 [Tumor Proportion Score (TPS) ≥1%] as determined by an FDA-approved test, with no EGFR or ALK genomic tumor aberrations, and is:

  • Stage III where patients are not candidates for surgical resection or definitive chemoradiation, or
  • metastatic.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with metastatic NSCLC whose tumors express PD-L1 (TPS ≥1%) as determined by an FDA-approved test, with disease progression on or after platinum-containing chemotherapy. Patients with EGFR or ALK genomic tumor aberrations should have disease progression on FDA-approved therapy for these aberrations prior to receiving KEYTRUDA.

KEYTRUDA is indicated for the treatment of patients with resectable (tumors ≥4 cm or node positive) NSCLC in combination with platinum-containing chemotherapy as neoadjuvant treatment, and then continued as a single agent as adjuvant treatment after surgery.

KEYTRUDA, as a single agent, is indicated as adjuvant treatment following resection and platinum-based chemotherapy for adult patients with Stage IB (T2a ≥4 cm), II, or IIIA NSCLC.

Head and Neck Squamous Cell Cancer

KEYTRUDA, in combination with platinum and fluorouracil (FU), is indicated for the first-line treatment of patients with metastatic or with unresectable, recurrent head and neck squamous cell carcinoma (HNSCC).

KEYTRUDA, as a single agent, is indicated for the first-line treatment of patients with metastatic or with unresectable, recurrent HNSCC whose tumors express PD-L1 [Combined Positive Score (CPS) ≥1] as determined by an FDA-approved test.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with recurrent or metastatic HNSCC with disease progression on or after platinum-containing chemotherapy.

Classical Hodgkin Lymphoma

KEYTRUDA is indicated for the treatment of adult patients with relapsed or refractory classical Hodgkin lymphoma (cHL).

KEYTRUDA is indicated for the treatment of pediatric patients with refractory cHL, or cHL that has relapsed after 2 or more lines of therapy.

Primary Mediastinal Large B-Cell Lymphoma

KEYTRUDA is indicated for the treatment of adult and pediatric patients with refractory primary mediastinal large B-cell lymphoma (PMBCL), or who have relapsed after 2 or more prior lines of therapy. KEYTRUDA is not recommended for treatment of patients with PMBCL who require urgent cytoreductive therapy.

Urothelial Cancer

KEYTRUDA, in combination with enfortumab vedotin, is indicated for the treatment of adult patients with locally advanced or metastatic urothelial cancer.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with locally advanced or metastatic urothelial carcinoma:

  • who are not eligible for any platinum-containing chemotherapy, or
  • who have disease progression during or following platinum-containing chemotherapy or within 12 months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS) with or without papillary tumors who are ineligible for or have elected not to undergo cystectomy.

Microsatellite Instability-High or Mismatch Repair Deficient Cancer

KEYTRUDA is indicated for the treatment of adult and pediatric patients with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options.

Microsatellite Instability-High or Mismatch Repair Deficient Colorectal Cancer

KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic MSI-H or dMMR colorectal cancer (CRC) as determined by an FDA-approved test.

Gastric Cancer

KEYTRUDA, in combination with trastuzumab, fluoropyrimidine- and platinum containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test.

This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval of this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials.

KEYTRUDA, in combination with fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma.

Esophageal Cancer

KEYTRUDA is indicated for the treatment of patients with locally advanced or metastatic esophageal or gastroesophageal junction (GEJ) (tumors with epicenter 1 to 5 centimeters above the GEJ) carcinoma that is not amenable to surgical resection or definitive chemoradiation either:

  • in combination with platinum- and fluoropyrimidine-based chemotherapy, or
  • as a single agent after one or more prior lines of systemic therapy for patients with tumors of squamous cell histology that express PD-L1 (CPS ≥10) as determined by an FDA-approved test.

Cervical Cancer

KEYTRUDA, in combination with chemoradiotherapy (CRT), is indicated for the treatment of patients with FIGO 2014 Stage III-IVA cervical cancer.

KEYTRUDA, in combination with chemotherapy, with or without bevacizumab, is indicated for the treatment of patients with persistent, recurrent, or metastatic cervical cancer whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test.

KEYTRUDA, as a single agent, is indicated for the treatment of patients with recurrent or metastatic cervical cancer with disease progression on or after chemotherapy whose tumors express PD-L1 (CPS ≥1) as determined by an FDA-approved test.

Hepatocellular Carcinoma

KEYTRUDA is indicated for the treatment of patients with hepatocellular carcinoma (HCC) secondary to hepatitis B who have received prior systemic therapy other than a PD-1/PD-L1-containing regimen.

Biliary Tract Cancer

KEYTRUDA, in combination with gemcitabine and cisplatin, is indicated for the treatment of patients with locally advanced unresectable or metastatic biliary tract cancer (BTC).

Merkel Cell Carcinoma

KEYTRUDA is indicated for the treatment of adult and pediatric patients with recurrent locally advanced or metastatic Merkel cell carcinoma (MCC).

Renal Cell Carcinoma

KEYTRUDA, in combination with axitinib, is indicated for the first-line treatment of adult patients with advanced renal cell carcinoma (RCC).

KEYTRUDA is indicated for the adjuvant treatment of patients with RCC at intermediate-high or high risk of recurrence following nephrectomy, or following nephrectomy and resection of metastatic lesions.

Endometrial Carcinoma

KEYTRUDA, in combination with carboplatin and paclitaxel, followed by KEYTRUDA as a single agent, is indicated for the treatment of adult patients with primary advanced or recurrent endometrial carcinoma.

KEYTRUDA, as a single agent, is indicated for the treatment of adult patients with advanced endometrial carcinoma that is MSI-H or dMMR, as determined by an FDA-approved test, who have disease progression following prior systemic therapy in any setting and are not candidates for curative surgery or radiation.

Tumor Mutational Burden-High Cancer

KEYTRUDA is indicated for the treatment of adult and pediatric patients with unresectable or metastatic tumor mutational burden-high (TMB-H) [≥10 mutations/megabase (mut/Mb)] solid tumors, as determined by an FDA-approved test, that have progressed following prior treatment and who have no satisfactory alternative treatment options.

This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in the confirmatory trials. The safety and effectiveness of KEYTRUDA in pediatric patients with TMB-H central nervous system cancers have not been established.

Cutaneous Squamous Cell Carcinoma

KEYTRUDA is indicated for the treatment of patients with recurrent or metastatic cutaneous squamous cell carcinoma (cSCC) or locally advanced cSCC that is not curable by surgery or radiation.

Merck’s focus on cancer

Every day, we follow the science as we work to discover innovations that can help patients, no matter what stage of cancer they have. As a leading oncology company, we are pursuing research where scientific opportunity and medical need converge, underpinned by our diverse pipeline of more than 25 novel mechanisms. With one of the largest clinical development programs across more than 30 tumor types, we strive to advance breakthrough science that will shape the future of oncology. By addressing barriers to clinical trial participation, screening and treatment, we work with urgency to reduce disparities and help ensure patients have access to high-quality cancer care. Our unwavering commitment is what will bring us closer to our goal of bringing life to more patients with cancer. For more information, visit https://www.merck.com/research/oncology.

About Merck

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit www.merck.com and connect with us on X (formerly Twitter), Facebook, Instagram, YouTube and LinkedIn.

SOURCE: Merck