Results of Phase II PRECEDENT Trial for Investigational Folate Receptor Therapy Vintafolide in Patients with Platinum-Resistant Ovarian Cancer Published in Journal of Clinical Oncology

Merck and Endocyte’s Phase III PROCEED pivotal trial of vintafolide in ovarian cancer ongoing

Monday, October 14, 2013 5:02 pm EDT



Public Company Information:

"The combination of vintafolide plus PLD demonstrated significant improvement in progression-free survival over standard treatment in women with folate receptor-positive platinum-resistant ovarian cancer"

WHITEHOUSE STATION N.J., & WEST LAFAYETTE, Ind.--(BUSINESS WIRE)--Merck, known as MSD outside the United States and Canada, (NYSE: MRK) and Endocyte, Inc. (NASDAQ: ECYT) today announced the online publication of results from the randomized Phase II PRECEDENT trial for vintafolide (MK-8109/EC145), an investigational folate small molecule drug conjugate (SMDC), in the Journal of Clinical Oncology (JCO), the official journal of the American Society of Clinical Oncology. These trial results are the basis for the vintafolide regulatory application currently under review with the European Medicines Agency for the treatment of folate-receptor positive platinum-resistant ovarian cancer in combination with pegylated liposomal doxorubicin (PLD). Enrollment is ongoing in the pivotal Phase III PROCEED clinical trial with vintafolide, along with investigational companion imaging agent etarfolatide (EC20), in platinum-resistant ovarian cancer ( NCT01170650).

As reported in JCO online, results from the Phase II PRECEDENT trial showed that administration of vintafolide plus pegylated liposomal doxorubicin (PLD) versus PLD alone in women with platinum-resistant ovarian cancer resulted in a median progression-free survival (PFS) of 5.0 months compared to 2.7 months for those treated with PLD alone (HR=0.63; 95% CI 0.41–0.96; p=0.031) in the intent-to-treat (ITT) population. Those patients shown to have folate receptor-positive tumors, as defined by all selected target lesions being folate receptor-positive (FR%100) using the investigational folate receptor-targeted companion diagnostic imaging agent etarfolatide, demonstrated greater benefit, as measured by PFS, from treatment with vintafolide plus PLD versus PLD alone. Median PFS benefit in these patients was 5.5 months compared to 1.5 months for PLD alone (HR=0.38; 95% CI 0.17–0.85; p=0.013). Etarfolatide is being developed by Endocyte as a non-invasive method to identify tumors that express the folate receptor.

“The combination of vintafolide plus PLD demonstrated significant improvement in progression-free survival over standard treatment in women with folate receptor-positive platinum-resistant ovarian cancer,” said R. Wendel Naumann, M.D., Associate Director, Gynecologic Oncology, Carolinas HealthCare System’s Levine Cancer Institute, Charlotte, N.C., and corresponding author of the publication. “Targeting the folate receptor, which is expressed on the majority of epithelial ovarian cancers, is a potentially promising strategy, especially when combined with a companion diagnostic that is designed to identify patients who are most likely to respond to the treatment, a hallmark of personalized medicine.”

The Phase II PRECEDENT trial was an international, multi-center, randomized study of 149 women with platinum-resistant ovarian cancer. Patients were randomized to receive vintafolide plus PLD or PLD alone at a standard dose, until disease progression or death. The primary endpoint of the study was PFS. Secondary endpoints included response rate and overall survival (OS). In the ITT population, no difference was observed in overall survival (HR=1.010; 95% CI 0.679–1.503; p=0.957). Endocyte first presented results from the Phase II PRECEDENT trial at the 2011 American Society of Clinical Oncology Annual Meeting.

The combination of vintafolide and PLD was generally well tolerated, and no drug-related mortality or statistically significant difference in the incidence of drug-related serious treatment-emergent adverse events (TEAEs) was observed.

  • In the vintafolide and PLD arm vs. PLD arm, anemia, neutropenia and thrombocytopenia were reported in 16.6% vs. 10.4%, 19.1% vs. 10.4%, and 2.7% vs. 3.0% of all cycles, respectively.
  • Stomatitis and palmar-plantar erythrodysesthesia (hand-foot syndrome) occurred in 16.6% vs. 22.8%, and 19.1% vs.15.8% of cycles, respectively.
  • The frequency of fatigue was similar between arms, 15.8% of vintafolide and PLD arm cycles, and 14.9% of PLD arm cycles.

About Folate Receptor-Positive Platinum-Resistant Ovarian Cancer

In 2013, it is estimated that there will be 22,240 new cases of ovarian cancer in the United States and over 40,000 new cases in the European Union. Ovarian cancer is one of the most lethal cancers of the female reproductive system. Overall, approximately 80 percent of patients relapse after first-line platinum-based chemotherapy. Platinum-resistant ovarian cancer is a challenging disease with a high unmet need. This type of cancer recurs within six months of completion with a platinum-containing regimen, the standard of care for ovarian cancer. Based on the Phase II PRECEDENT trial data, an estimated 80 percent of platinum-resistant ovarian cancer patients have been found to have folate receptor-positive disease as assessed by etarfolatide scanning, and approximately 40 percent express the receptor, as detected by etarfolatide, in all of their target tumor lesions.

About Vintafolide (MK-8109/EC145)

Vintafolide is an investigational proprietary, injectable, folate SMDC consisting of folate (vitamin B9) linked to a potent vinca alkaloid chemotherapy agent, desacetylvinblastine hydrazide (DAVLBH). Vintafolide is designed to target the chemotherapy agent to rapidly growing cancer cells that actively take up folate via the folate receptor. The folate receptor is expressed in a wide variety of cancers including ovarian cancer.

Vintafolide (MK-8109/EC145) in combination with PLD is currently under review with European Medicines Agency (EMA) for the treatment of adult patients with folate receptor-positive platinum-resistant ovarian cancer. Vintafolide has also been granted orphan drug status by the European Commission. Vintafolide, along with investigational companion imaging agent etarfolatide, is currently being evaluated in a Phase III PROCEED clinical trial for platinum-resistant ovarian cancer, ( NCT01170650) and a Phase IIb TARGET trial for non-small cell lung cancer (NSCLC) ( NCT01577654). A Phase II randomized trial of vintafolide in folate receptor-positive triple negative breast cancer is expected to be initiated in the near future.

As part of an exclusive license agreement with Endocyte, Merck is responsible for the development and worldwide commercialization of vintafolide. Endocyte would intend to co-promote vintafolide in the U.S. pending regulatory filing and approval, and is responsible for the development, manufacture and commercialization of etarfolatide worldwide.

About Etarfolatide (EC20)

Etarfolatide is an investigational folate receptor-targeted companion diagnostic imaging agent that is being developed as a non-invasive method to identify tumors that express the folate receptor. These tumors are the molecular target of Endocyte's folate receptor-targeted therapeutic compounds such as vintafolide. Folic acid is used with etarfolatide for the enhancement of image quality. Etarfolatide is under review with the EMA and has been granted orphan drug status by the European Commission.

About Merck

Today’s Merck is a global healthcare leader working to help the world be well. Merck is known as MSD outside the United States and Canada. Through our prescription medicines, vaccines, biologic therapies, and consumer care and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. For more information, visit and connect with us on Twitter, Facebook and YouTube.

About Endocyte

Endocyte is a biopharmaceutical company developing targeted therapies for the treatment of cancer and other serious diseases. Endocyte uses its proprietary technology to create novel SMDCs and companion imaging diagnostics for personalized targeted therapies. The company's SMDCs actively target receptors that are expressed on diseased cells, relative to healthy cells. This targeted approach is designed to enable the treatment of patients with highly active drugs at greater doses, delivered more frequently and over longer periods of time than would be possible with the untargeted drug alone. The companion imaging diagnostics are designed to identify patients whose disease expresses the molecular target of the therapy and who are therefore more likely to benefit from treatment. Targeted SMDCs for cancer, inflammatory disorders and kidney disease are in preclinical development. For additional information, please visit Endocyte's website at

Merck Forward-Looking Statement

This news release includes “forward-looking statements” within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. These statements are based upon the current beliefs and expectations of Merck’s management and are subject to significant risks and uncertainties. There can be no guarantees with respect to pipeline products that the products will receive the necessary regulatory approvals or that they will prove to be commercially successful. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; Merck’s ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of Merck’s patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merck’s 2012 Annual Report on Form 10-K and the company’s other filings with the Securities and Exchange Commission (SEC) available at the SEC’s Internet site (

Endocyte Forward-Looking Statement

Certain of the statements in this press release are forward looking, such as those, among others, relating to the potential effectiveness of folate receptor-targeted therapies, the ability to determine the folate receptor expression status of patients, and the timing of clinical trial enrollment. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. More information about the risks and uncertainties faced by Endocyte, Inc. is contained in the company's periodic reports filed with the Securities and Exchange Commission. Endocyte, Inc. disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.


Caroline Lappetito,267-305-7639
Claire Mulhearn, 908-423-7425
Carol Ferguson, 908-423-4465
Justin Holko, 908-423-5088
Tony Russo, 212-845-4251
Martina Schwarzkopf, 212-845-4292
Stephanie Ascher, 212-362-1200

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