Nature of Business and Organization	9 Months Ended
Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Organization	1. Nature of Business and Organization Endocyte, Inc. (the “Company”) is a biopharmaceutical company and leader in developing targeted therapies for the treatment of cancer. The Company uses drug conjugation technology to create novel therapeutics and companion imaging agents for personalized targeted therapies. The agents actively target receptors that are over-expressed on diseased cells relative to healthy cells, such as prostate specific membrane antigen (“PSMA”) in prostate cancer. This targeted approach is designed to safely enable the delivery of highly potent drug payloads. The companion imaging agents are designed to identify patients whose disease over-expresses the target of the therapy and who are therefore more likely to benefit from treatment. On October 17, 2018, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Novartis AG (“Novartis”) and Edinburgh Merger Corporation, a wholly owned subsidiary of Novartis (“Merger Sub”), subject to the terms and conditions of which the Company will be acquired by Novartis for $24.00 per share in cash through the merger of Merger Sub with and into the Company, with the Company continuing as the surviving corporation and a wholly-owned subsidiary of Novartis (the “Merger”). The consummation of the Merger is subject to certain closing conditions, including the requisite approval of our stockholders and the receipt of certain antitrust and regulatory approvals. See Note 13 – Subsequent Event of the Notes to Condensed Financial Statements contained herein for additional information regarding the Merger, and see “Risk Factors” in Part II, Item 1A herein for important information regarding certain risks associated with the Merger Agreement and the Merger. In September 2017, the Company entered into a Development and License Agreement (the “License Agreement”) with ABX advanced biochemical compounds – Biomedizinische Forschungsreagenzien GmbH (“ABX”), pursuant to which the Company acquired exclusive worldwide rights to develop and commercialize PSMA-617 agents, including the product candidate known as 177Lu-PSMA-617, a radioligand therapeutic (“RLT”). Following a successful End of Phase 2 meeting with the U.S. Food and Drug Administration (the “FDA”), in early 2018, the Company finalized the initial phase 3 VISION trial design and registration plan for 177Lu-PSMA-617. In the three months ended June 30, 2018, the Company initiated enrollment of the VISION trial, an international, prospective, open-label, multicenter, randomized phase 3 study of 177Lu-PSMA-617 enrolling up to 750 patients with progressive PSMA-positive metastatic castration-resistant prostate cancer (“mCRPC”). 177Lu-PSMA-617 utilizes a high affinity targeting ligand to direct potent radiotherapy to prostate cancer cells. The specific targeting of this therapy comes from the "ligand" portion of the RLT, which is a small molecule designed to bind to PSMA, a protein highly expressed on the cell surface of most prostate cancer cells but absent on most normal cells. The PSMA targeting ligand in 177Lu-PSMA-617 is chemically attached to a therapeutic radioactive atom called Lutetium-177 (177Lu), which releases an energetic beta particle designed to precisely deliver cell-killing radiation to the site of disease. Unlike traditional external beam radiotherapy, 177Lu-PSMA-617, which is administered as a systemic injection, has been designed to directly target multiple sites of PSMA-positive prostate cancer throughout the body, including the bone and soft tissue, while bypassing the PSMA-negative cells. Prior to treatment with 177Lu-PSMA-617, the patient's expression of PSMA can be determined using imaging technology, allowing for personalization of treatment so that the optimum course of therapy might be selected. As highlighted in roughly 20 peer reviewed publications of trials in the post-chemotherapy compassionate use setting, 177Lu-PSMA-617 demonstrated a prostate-specific antigen (“PSA”) response (defined as greater than 50% decline from baseline) in 40% to 60% of patients, and a Response Evaluation Criteria in Solid Tumors (“RECIST”) response rate in soft tissue disease of between 40% and 50%. On September 10, 2018, the Company announced that, following a meeting with the FDA, it was determined that radiographic progression free survival (“rPFS”) is an appropriate efficacy endpoint in the ongoing phase 3 VISION trial to support the submission of a New Drug Application (“NDA”) for full FDA approval of 177Lu-PSMA-617 for the treatment of mCRPC. The updated trial protocol will reflect this determination on rPFS while retaining the final, fully powered overall survival (“OS”) analysis. Under the updated VISION trial design, the two interim assessments previously planned at 50% and 70% of OS events will be replaced with a single assessment of rPFS. This assessment is expected to occur at approximately the same time that the first interim OS assessment would have occurred under the prior trial design and shortly after the time the trial is fully enrolled. If 177Lu-PSMA-617 meets the primary endpoint in the rPFS assessment, no unexpected safety issues arise, and it demonstrates no detriment in OS relative to the control arm, the Company intends to submit an NDA to seek full approval in the United States. The rPFS analysis will include approximately 450 rPFS events. Regardless of the outcome of the rPFS assessment, the Company intends to continue to follow patients in the VISION trial in order to assess the final OS alternative primary endpoint. An efficacy analysis of OS will be conducted at approximately 490 events. Other aspects of the VISION trial design, including patient treatment and assessments, study size, overall duration, and follow up remain unchanged. Secondary endpoints include RECIST response and time to first symptomatic skeletal event.

1. Nature of Business and Organization

Endocyte, Inc. (the “Company”) is a biopharmaceutical company and leader in developing targeted therapies for the treatment of cancer. The Company uses drug conjugation technology to create novel therapeutics and companion imaging agents for personalized targeted therapies. The agents actively target receptors that are over-expressed on diseased cells relative to healthy cells, such as prostate specific membrane antigen (“PSMA”) in prostate cancer. This targeted approach is designed to safely enable the delivery of highly potent drug payloads. The companion imaging agents are designed to identify patients whose disease over-expresses the target of the therapy and who are therefore more likely to benefit from treatment.

On October 17, 2018, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Novartis AG (“Novartis”) and Edinburgh Merger Corporation, a wholly owned subsidiary of Novartis (“Merger Sub”), subject to the terms and conditions of which the Company will be acquired by Novartis for $24.00 per share in cash through the merger of Merger Sub with and into the Company, with the Company continuing as the surviving corporation and a wholly-owned subsidiary of Novartis (the “Merger”). The consummation of the Merger is subject to certain closing conditions, including the requisite approval of our stockholders and the receipt of certain antitrust and regulatory approvals. See Note 13 – Subsequent Event of the Notes to Condensed Financial Statements contained herein for additional information regarding the Merger, and see “Risk Factors” in Part II, Item 1A herein for important information regarding certain risks associated with the Merger Agreement and the Merger.

In September 2017, the Company entered into a Development and License Agreement (the “License Agreement”) with ABX advanced biochemical compounds – Biomedizinische Forschungsreagenzien GmbH (“ABX”), pursuant to which the Company acquired exclusive worldwide rights to develop and commercialize PSMA-617 agents, including the product candidate known as 177Lu-PSMA-617, a radioligand therapeutic (“RLT”). Following a successful End of Phase 2 meeting with the U.S. Food and Drug Administration (the “FDA”), in early 2018, the Company finalized the initial phase 3 VISION trial design and registration plan for 177Lu-PSMA-617.

In the three months ended June 30, 2018, the Company initiated enrollment of the VISION trial, an international, prospective, open-label, multicenter, randomized phase 3 study of 177Lu-PSMA-617 enrolling up to 750 patients with progressive PSMA-positive metastatic castration-resistant prostate cancer (“mCRPC”). 177Lu-PSMA-617 utilizes a high affinity targeting ligand to direct potent radiotherapy to prostate cancer cells. The specific targeting of this therapy comes from the "ligand" portion of the RLT, which is a small molecule designed to bind to PSMA, a protein highly expressed on the cell surface of most prostate cancer cells but absent on most normal cells. The PSMA targeting ligand in 177Lu-PSMA-617 is chemically attached to a therapeutic radioactive atom called Lutetium-177 (177Lu), which releases an energetic beta particle designed to precisely deliver cell-killing radiation to the site of disease. Unlike traditional external beam radiotherapy, 177Lu-PSMA-617, which is administered as a systemic injection, has been designed to directly target multiple sites of PSMA-positive prostate cancer throughout the body, including the bone and soft tissue, while bypassing the PSMA-negative cells. Prior to treatment with 177Lu-PSMA-617, the patient's expression of PSMA can be determined using imaging technology, allowing for personalization of treatment so that the optimum course of therapy might be selected. As highlighted in roughly 20 peer reviewed publications of trials in the post-chemotherapy compassionate use setting, 177Lu-PSMA-617 demonstrated a prostate-specific antigen (“PSA”) response (defined as greater than 50% decline from baseline) in 40% to 60% of patients, and a Response Evaluation Criteria in Solid Tumors (“RECIST”) response rate in soft tissue disease of between 40% and 50%.

On September 10, 2018, the Company announced that, following a meeting with the FDA, it was determined that radiographic progression free survival (“rPFS”) is an appropriate efficacy endpoint in the ongoing phase 3 VISION trial to support the submission of a New Drug Application (“NDA”) for full FDA approval of 177Lu-PSMA-617 for the treatment of mCRPC. The updated trial protocol will reflect this determination on rPFS while retaining the final, fully powered overall survival (“OS”) analysis.

Under the updated VISION trial design, the two interim assessments previously planned at 50% and 70% of OS events will be replaced with a single assessment of rPFS. This assessment is expected to occur at approximately the same time that the first interim OS assessment would have occurred under the prior trial design and shortly after the time the trial is fully enrolled. If 177Lu-PSMA-617 meets the primary endpoint in the rPFS assessment, no unexpected safety issues arise, and it demonstrates no detriment in OS relative to the control arm, the Company intends to submit an NDA to seek full approval in the United States. The rPFS analysis will include approximately 450 rPFS events. Regardless of the outcome of the rPFS assessment, the Company intends to continue to follow patients in the VISION trial in order to assess the final OS alternative primary endpoint. An efficacy analysis of OS will be conducted at approximately 490 events. Other aspects of the VISION trial design, including patient treatment and assessments, study size, overall duration, and follow up remain unchanged. Secondary endpoints include RECIST response and time to first symptomatic skeletal event.