Endocyte Enrolls First Patient in Phase 1 Study for the Small Molecule Drug Conjugate EC1456, a Folate-Targeted Tubulysin Conjugate in Advanced Solid Tumors

WEST LAFAYETTE, Ind., Dec. 12, 2013 (GLOBE NEWSWIRE) -- Endocyte, Inc. (Nasdaq:ECYT), a biopharmaceutical company and leader in targeted small molecule drug conjugates (SMDCs) and companion imaging agents for personalized therapy in cancer and other serious diseases, today announced that it has dosed the first patient in its Phase 1 clinical trial in advanced solid tumors for its SMDC EC1456, a folate receptor (FR)-targeting folate-tubulysin conjugate.

The open-label, multicenter, non-randomized, dose-escalation study is divided into two parts. The first part of the Phase 1 study will evaluate the maximum tolerated dose (MTD) and recommended Phase 2 dose of EC1456 in patients with metastatic or locally advanced solid tumors, the primary endpoint of the study.

The second part of the study will determine the efficacy of EC1456 in patients with select cancers known to express the folate receptor with all target lesions positive for FR [FR(100%)] and treated with MTD. The FR-status will be determined using the investigational companion imaging agent, etarfolatide (EC20).

"We continue to expand our SMDC portfolio and companion imaging agents as we move our second drug candidate, EC1456, into the clinic," said Ron Ellis, president and CEO of Endocyte. "Our companion imaging agent, etarfolatide, is being investigated to identify cancer patients who express the folate receptor and are likely to respond to this targeted and highly potent drug conjugate. The possibility to utilize molecular analysis to manage an individual patient's disease is the hallmark of precision medicine and having the possibility to evaluate a disease status or all of a patient's cancer lesions in real time will help to achieve optimal medical outcomes for patients and physicians."

Christopher Leamon, Ph.D., vice president of research of Endocyte, added, "EC1456 combines the FR precision targeting component of vintafolide with the extremely potent cytotoxic molecule, tubulysin. As demonstrated with strong preclinical data, EC1456 holds promise for treating FR-positive patients who have become resistant to other drugs, such as paclitaxel and vintafolide as well as cancers that express lower levels of the folate receptor."

The first part of the study will enroll an estimate of 30 patients with metastatic or locally advanced solid tumors who have failed to respond to standard therapy if available. The second part of the study will enroll 10 patients each with the advanced solid cancer indication, such as triple-negative breast cancer (TNBC), advanced non-small cell lung cancer (NSCLC), ovarian cancer and hepatocellular carcinoma (HCC), who have received no more than two prior chemotherapies. Secondary endpoints include safety profile of EC1456, efficacy and pharmacokinetic analysis as well as the correlation between baseline folate expression measured by etarfolatide scans and antitumor activity of EC1456.

About EC1456

EC1456 is an investigational proprietary, injectable, SMDC consisting of folate (vitamin B9) linked to a potent cytotoxic agent, tubulysin B hydrazide (TubBH). EC1456 is wholly owned by Endocyte. TubBH is a member of the tubulysin class of anti-neoplastic agents that inhibit the polymerization of tubulin into microtubules, a critical component during cell division. The targeting ligand folate, essential for cell division, has been investigated with vintafolide. EC1456 is currently being evaluated in a Phase 1 study in patients with advanced solid tumors (Clinicaltrials.gov NCT01999738).

About Etarfolatide (EC20)

Etarfolatide is an investigational FR-targeted companion imaging agent that is being developed as a non-invasive method to identify tumors that express the FR. These tumors are the molecular target of Endocyte's FR-targeted therapeutic compounds such as vintafolide and EC1456. 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 Endocyte

Endocyte is a biopharmaceutical company and leader in developing targeted small molecule drug conjugates (SMDCs) and companion imaging agents for personalized therapy in cancer and other serious diseases. Endocyte uses its proprietary technology to create novel SMDCs and companion imaging agents for personalized targeted therapies. The company's SMDCs actively target receptors that are expressed or over-expressed on diseased cells, relative to healthy cells. This targeted approach is designed to enable the treatment of patients with highly potent drugs into these cells. The companion imaging agents are designed to identify patients whose disease expresses the molecular target of the therapy and who therefore may be more likely to benefit from treatment. For more information, visit http://www.endocyte.com.

Endocyte Forward-Looking Statement

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the company's expectations for seeking regulatory approval and commercial launch of its products, including any conditional marketing authorization from the EMA, initiation of future clinical trials, and expectations for the receipt of milestones, royalties or other profits from the partnership. Actual results or developments may differ materially from those projected or implied in these forward-looking statements. Factors that may cause such a difference include risks that the company may experience delays in the completion of its clinical trials (whether caused by competition, adverse events, patient enrollment rates, unavailability of PLD, regulatory issues or other factors); risks that data from its clinical trials may not be indicative of subsequent clinical trial results; risks related to the safety and efficacy of the company's product candidates, the goals of its development activities, estimates of the potential markets for its product candidates, estimates of the capacity of manufacturing and other facilities required to support its product candidates, projected cash needs, and expected financial results. 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.

CONTACT: Stephanie Ascher, Stern Investor Relations, Inc., (212) 362-1200, stephanie@sternir.com Martina Schwarzkopf, Ph.D., Russo Partners, (212) 845-4292, martina.schwarzkopf@russopartnersllc.com Tony Russo, Ph.D., Russo Partners, (212) 845-4251, tony.russo@russopartnersllc.comSource:Endocyte, Inc.