Endocyte Presents Data from its CAR T Platform at American Association for Cancer Research (AACR) Annual Meeting 2018

WEST LAFAYETTE, Ind., April 16, 2018 -- Endocyte, Inc. (Nasdaq:ECYT), a biopharmaceutical company developing targeted therapeutics for personalized cancer treatment, today announced in a late-breaking poster session the presentation of new research from Endocyte’s chimeric antigen receptor T-cell (CAR T) adaptor molecule (CAM) platform at the AACR Annual Meeting 2018 in Chicago, IL.

“We are pleased to present data that support the utility of our unique CAR T platform, which potentially enables us to control cytokine release syndrome (CRS), manage T-cell exhaustion and address heterogeneity in both solid and liquid tumors through the administration of multiple CAMs,” said Chris Leamon, vice president, research and development of Endocyte. “These findings are critical towards identifying the dosing regimen and confirming the anti-tumor activity of EC17/CAR T, our folate-targeted CAM-based therapy, as we look to initiate a phase 1 trial in osteosarcoma later this year.”

Endocyte’s CAM-based therapies consist of a single universal autologous CAR T-cell, designed to bind with high affinity to FITC. This universal CAR T-cell can be specifically directed to cancer cells through the administration of a bi-specific adaptor molecule targeted to both FITC and a tumor target, which acts to bridge the universal CAR T-cell with the cancer cells. This allows for control of the antigen target through the administration of the CAM, in contrast to current CAR T-cell therapies, in which the antigen targets are not controlled.

The data presented at AACR show that EC17 penetrates solid tumors within minutes and is retained due to high affinity for the folate receptor (FR), while unbound EC17 rapidly clears from the blood and receptor-negative tissues. When tested against human xenografts, EC17/CAR T-cell therapy has shown consistent antitumor activity with low or no adverse reactions. For translation into first-in-human testing, clinically relevant dosing regimens were evaluated using tumor-free and tumor-bearing mice to study CAR T-cell proliferation, cytokine production and the onset/mitigation of CRS. Preclinically, EC17/CAR T-cell therapy has demonstrated meaningful efficacy against some of the more aggressive and chemo-resistant FR+ tumors of various histology.

Although CRS could be triggered in this study, it could also be mitigated, or even prevented, using intermittent dosing and/or dose titration of the EC17 CAM. Under extreme conditions where dose cessation failed, intravenous sodium fluorescein (NaFl) could be used as a fast-acting rescue agent to temporarily displace CAR T-cells from their targets and reverse the CRS.

Website Information
Endocyte routinely posts important information for investors on its website, www.endocyte.com, in the “Investors & News” section. Endocyte uses this website as a means of disclosing material information in compliance with its disclosure obligations under Regulation FD. Accordingly, investors should monitor the “Investors & News” section of Endocyte’s website, in addition to following its press releases, SEC filings, public conference calls, presentations and webcasts. The information contained on, or that may be accessed through, Endocyte’s website is not incorporated by reference into, and is not a part of, this document.

About Endocyte

Endocyte is a biopharmaceutical company and leader in developing targeted therapies for the personalized treatment of cancer. The company's drug conjugation technology targets therapeutics and companion imaging agents specifically to the site of diseased cells. Endocyte's lead program is a prostate specific membrane antigen (PSMA)-targeted radioligand therapy, ¹⁷⁷Lu-PSMA-617, entering phase 3 for metastatic castration resistant prostate cancer (mCRPC). Endocyte is also advancing its adaptor-controlled CAR T-cell therapy into the clinic in 2018, where it will be studied in osteosarcoma. For additional information, please visit Endocyte's website at www.endocyte.com.

Forward Looking Statements – Legal to Update

Certain of the statements made in this press release are forward looking, such as those, among others, relating to the company's future development plans including those relating to the completion of pre-clinical development in preparation for possible future clinical trials, the anticipated initiation of a registration trial, and preparation for potential commercialization. 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 or independent investigators may experience delays in the initiation or completion of clinical trials (whether caused by competition, adverse events, patient enrollment rates, shortage of clinical trial materials, regulatory issues or other factors); risks that data from prior clinical trials may not be indicative of subsequent clinical trial results; risks related to the safety and efficacy of the company’s product candidates; risks that early stage pre-clinical data may not be indicative of subsequent data when expanded to additional pre-clinical models or to subsequent clinical data; risks that evolving competitive activity and intellectual property landscape may impair the company's ability to capture value for the technology; risks that expectations and estimates turn out to be incorrect, including estimates of the potential markets for the company’s product candidates, estimates of the capacity of manufacturing and other facilities required to support its product candidates, projected cash needs, and expected future revenues, operations, expenditures and cash position. 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.

Investor Contact:
Stephanie Ascher, Stern Investor Relations, Inc., (212) 362-1200, [email protected]