KEYTRUDA plus concurrent chemoradiotherapy reduced the risk of disease progression or death by 30% compared to concurrent chemoradiotherapy alone

KEYNOTE-A18 is the first Phase 3 study in which an immunotherapy regimen has demonstrated a significant PFS improvement in locally advanced cervical cancer compared to concurrent chemoradiotherapy alone

RAHWAY, NJ, USA I October 20, 2023 I Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced results from the pivotal Phase 3 KEYNOTE-A18 trial, also known as ENGOT-cx11/GOG-3047, investigating KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with external beam radiotherapy (EBRT) plus concurrent chemotherapy, followed by brachytherapy (also known as concurrent chemoradiotherapy) for newly diagnosed patients with high-risk locally advanced cervical cancer (stage 1B2-2B with lymph node-positive disease, and stage 3-4A with and without lymph node-positive disease). Results from the trial showed that KEYTRUDA in combination with concurrent chemoradiotherapy demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) compared to concurrent chemoradiotherapy alone for these patients. The findings are being presented for the first time today at 10:45 a.m. ET during a late-breaking abstract proffered paper session at the European Society for Medical Oncology (ESMO) Congress 2023 (abstract #LBA38).

After a median follow-up of 17.9 months (range, 0.9-31.0), the KEYTRUDA regimen reduced the risk of disease progression or death by 30% (HR=0.70 [95% CI, 0.55-0.89]; p=0.0020) versus concurrent chemoradiotherapy alone in these patients. Median PFS was not reached in either group. The 24-month PFS rate was 67.8% for patients who received the KEYTRUDA regimen compared to 57.3% for those who received concurrent chemoradiotherapy alone. In addition to an improvement in PFS, a favorable trend in overall survival (OS), the trial’s other primary endpoint, was observed for the KEYTRUDA regimen versus concurrent chemoradiotherapy alone (HR=0.73 [95% CI, 0.49-1.07]); with only 103 events across both groups, these OS data are not mature and did not reach statistical significance at the time of this interim analysis. The trial is continuing, and follow-up of OS is ongoing. The safety profile of KEYTRUDA in this trial was consistent with that observed in previously reported studies; no new safety signals were identified.

“Cervical cancer is the fourth most common cancer in women worldwide; however, over the past two decades, new treatment advances have been limited for patients diagnosed with locally advanced disease,” said Dr. Gursel Aktan, vice president, global clinical development, Merck Research Laboratories. “These positive results from the KEYNOTE-A18 trial demonstrate the potential of KEYTRUDA in combination with concurrent chemoradiotherapy as a new treatment option for patients with high-risk cervical cancer, building on the established role of KEYTRUDA for certain patients with advanced cervical cancer and our research efforts in earlier stages of disease.”

“This is the first phase 3 study in which an immunotherapy has demonstrated an improvement in progression-free survival in this patient population compared to standard of care,” said professor Domenica Lorusso, the study’s overall principal investigator, lead investigator for ENGOT and associate professor of Obstetrics and Gynecology at the Catholic University of Rome. “The results of this trial, finding the KEYTRUDA regimen reduced the risk of disease progression or death by 30% compared to concurrent chemoradiotherapy alone, are compelling, especially considering newly diagnosed patients with high-risk locally advanced cervical cancer have not seen an advance in treatment options in 20 years.”

“Patients diagnosed with locally advanced cervical cancer face a poor prognosis and limited treatment options,” said Dr. Bradley Monk, oncologist and professor of obstetrics and gynecology at University of Arizona’s College of Medicine and Creighton University School of Medicine. “These results demonstrate that by moving an immunotherapy regimen to earlier stages of cervical cancer, we have the potential to improve outcomes for these patients compared to the current standard of care.”

Merck previously announced that based on these positive results, the U.S. Food and Drug Administration (FDA) has granted priority review for a supplemental Biologics License Application (sBLA) for KEYTRUDA in combination with concurrent chemoradiotherapy for the treatment of newly diagnosed patients with high-risk locally advanced cervical cancer. The FDA has set a Prescription Drug User Fee Act, or target action, date of January 20, 2024. The results are also being discussed with regulatory authorities worldwide.

In the U.S., KEYTRUDA has two approved indications in cervical cancer: in combination with chemotherapy, with or without bevacizumab, for the treatment of patients with persistent, recurrent, or metastatic cervical cancer whose tumors express PD-L1 (Combined Positive Score [CPS] ≥1) as determined by an FDA-approved test; and as a single agent, 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.

As announced, data spanning more than 15 types of cancer are being presented from Merck’s broad oncology portfolio and investigational pipeline at the ESMO Congress 2023.

Study design and additional data from KEYNOTE-A18/ENGOT-cx11/GOG-3047

KEYNOTE-A18, also known as ENGOT-cx11/GOG-3047, is a randomized, double-blind Phase 3 trial (ClinicalTrials.gov, NCT04221945) sponsored by Merck and conducted in collaboration with the European Network for Gynaecological Oncology Trial (ENGOT) groups and the GOG Foundation, Inc. (GOG) evaluating KEYTRUDA in combination with EBRT plus concurrent chemotherapy (cisplatin), followed by brachytherapy (also known as concurrent chemoradiotherapy) compared to placebo plus concurrent chemoradiotherapy for the treatment of newly diagnosed high-risk (stage 1B2-2B with lymph node-positive disease, and stage 3-4A with and without lymph node-positive disease) locally advanced cervical cancer where patients are treated with definitive intent. The primary endpoints are PFS and OS, and secondary endpoints include complete response rate, objective response rate and safety. The trial enrolled 1,060 patients who were randomized to receive:

  • KEYTRUDA (200 mg intravenously [IV]) on Day 1 of each three-week cycle (Q3W) for five cycles followed by KEYTRUDA (400 mg by IV) on Day 1 of each six-week cycle (Q6W) for an additional 15 cycles plus concurrent chemoradiotherapy (cisplatin 40 mg/m2 by IV once per week [QW] for five or six weeks plus EBRT followed by brachytherapy with minimum total radiotherapy dose of 80 Gray Units [Gy] for volume-directed and 75 Gy for point-directed given with the total duration of radiation treatment not to exceed 50 days [with an extension to a maximum of 56 days for unforeseen delays]); or
  • Placebo plus concurrent chemoradiotherapy (cisplatin 40 mg/m2 by IV QW for five or six weeks plus EBRT followed by brachytherapy with minimum total radiotherapy dose of 80 Gy for volume-directed and 75 Gy for point-directed given with the total duration of radiation treatment not to exceed 50 days [with an extension to a maximum of 56 days for unforeseen delays]).

The safety profile of KEYTRUDA was consistent with that observed in previously reported studies. Treatment-related adverse events (TRAEs) occurred in 96% of patients receiving the KEYTRUDA regimen and 96% of patients receiving the placebo regimen; Grade 3-5 TRAEs occurred in 67.0% versus 60.6%, respectively. Treatment-related adverse events led to discontinuation of all study treatment in 0% of patients treated with the KEYTRUDA regimen and 0.2% treated with the placebo regimen. Additionally, TRAEs led to death in two (0.4%) patients receiving the KEYTRUDA regimen and two (0.4%) patients receiving the placebo regimen. No new safety concerns were identified.

Immune-mediated adverse events (AEs) of any grade occurred in 32.6% of patients receiving the KEYTRUDA regimen and 11.7% of patients receiving the placebo regimen. Grade 3-5 immune-mediated AEs occurred in 4.2% versus 1.1%, respectively. The most common of these all-grade immune-mediated AEs (occurring in more than two patients) was hypothyroidism (19.3%) in patients receiving the KEYTRUDA regimen. Immune-mediated AEs did not lead to death in either arm.

About Merck’s research in breast and gynecologic cancers

Merck is advancing research aimed at improving outcomes for patients affected by breast and gynecologic (ovarian, cervical and endometrial) cancers. Merck has a comprehensive clinical development program in across these cancers comprised of more than 20 Merck-sponsored Phase 3 studies evaluating KEYTRUDA as monotherapy and in combination with other medicines. In the U.S., KEYTRUDA currently has two approved indications for triple-negative breast cancer, include one for high-risk early-stage disease, and four approved indications across certain types of advanced cervical and endometrial cancers (see indications below). Among Merck’s research efforts are trials focused on evaluating KEYTRUDA in earlier stages of these cancers as well as identifying new combinations and coformulations with KEYTRUDA.

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 studying KEYTRUDA in earlier disease states, with more than 25 ongoing registrational studies across multiple types of cancer, including KEYNOTE-A18.

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.

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.

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 Carcinoma

KEYTRUDA, in combination with enfortumab vedotin, is indicated for the treatment of adult patients with locally advanced or metastatic urothelial carcinoma (mUC) who are not eligible for cisplatin-containing chemotherapy.

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.

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 patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma.

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.

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.

Hepatocellular Carcinoma

KEYTRUDA is indicated for the treatment of patients with hepatocellular carcinoma (HCC) who have been previously treated with sorafenib.

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.

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, as a single agent, is indicated for the treatment of 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.

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.

Merck’s focus on cancer

Our goal is to translate breakthrough science into innovative oncology medicines to help people with cancer worldwide. At Merck, the potential to bring new hope to people with cancer drives our purpose and supporting accessibility to our cancer medicines is our commitment. As part of our focus on cancer, Merck is committed to exploring the potential of immuno-oncology with one of the largest development programs in the industry across more than 30 tumor types. We also continue to strengthen our portfolio through strategic acquisitions and are prioritizing the development of several promising oncology candidates with the potential to improve the treatment of advanced cancers. For more information about our oncology clinical trials, visit www.merck.com/clinicaltrials.

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 Twitter, Facebook, Instagram, YouTube and LinkedIn.

SOURCE: Merck