Description of Business and Basis of Presentation	12 Months Ended
Apr. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Note 1. Description of Business and Basis of Presentation KalVista Pharmaceuticals, Inc. (together with its subsidiaries, “KalVista” or the “Company”) is a clinical stage pharmaceutical company focused on the discovery, development and commercialization of small molecule protease inhibitors for diseases with significant unmet need. The Company’s first product candidates are inhibitors of plasma kallikrein being developed for two indications: hereditary angioedema (“HAE”) and diabetic macular edema (“DME”). The Company applies its insights into the chemistry of proteases and, with current programs, the biology of the plasma kallikrein system, to develop small molecule inhibitors with high selectivity, potency and bioavailability that it believes will make them successful treatments for HAE and DME. KalVista has created a structurally diverse portfolio of oral plasma kallikrein inhibitors and advanced multiple drug candidates into clinical trials in order to create best-in-class oral therapies for both HAE and DME. The Company is currently evaluating KVD900 in a Phase 2 clinical study as a potential on-demand therapy for acute HAE attacks, which is expected to complete in the second half of 2020. KVD824 is KalVista’s next oral program to be developed for HAE, and the Company plans to commence a Phase 2 clinical trial intended to evaluate KVD824 as a twice-daily potential oral prophylactic treatment for HAE in the second half of 2020. In the case of DME, the Company is initially developing a plasma kallikrein inhibitor which is administered directly into the eye and anticipates ultimate development of orally delivered drugs. The KVD001 program, which was the lead DME candidate, as well as KalVista’s planned future oral DME programs were subject to an option agreement with Merck Sharpe & Dohme Corp. (“Merck”) entered into in 2017 (the “Option Agreement”). Under the terms of the Option Agreement, Merck had a defined period following receipt of a clinical data package including the results of the Phase 2 trial for KVD001, which were announced in December 2019, to determine whether to exercise its option to acquire KVD001 and to maintain its option on the oral DME programs. In February 2020, Merck notified the Company that those options would not be exercised. As a result, KalVista has retained all the rights and intellectual property that were subject to the Option Agreement, Merck has no further rights or obligations to the Company and the Company has no obligations to Merck. The Company’s headquarters is located in Cambridge, Massachusetts, with research activities located in Porton Down, United Kingdom and Boston, Massachusetts. The Company has devoted substantially all of its efforts to research and development, including clinical trials of its product candidates. The Company has not completed the development of any product candidates. Pharmaceutical drug product candidates, like those being developed by the Company, require approvals from the U.S. Food and Drug Administration (“FDA”) or foreign regulatory agencies prior to commercial sales. There can be no assurance that any product candidates will receive the necessary approvals and any failure to receive approval or delay in approval may have a material adverse impact on the Company’s business and financial results. The Company has not yet commenced commercial operations. The Company is subject to a number of risks and uncertainties similar to those of other life science companies developing new products, including, among others, the risks related to the necessity to obtain adequate additional financing, to successfully develop product candidates, to obtain regulatory approval of product candidates, to comply with government regulations, to successfully commercialize its potential products, to the protection of proprietary technology and to the dependence on key individuals. The Company has funded its operations primarily through the issuance of stock and the Option Agreement. As of April 30, 2020, the Company had an accumulated deficit of $121.6 million and cash, cash equivalents and marketable securities totaling $67.7 million. The Company’s working capital, primarily cash and marketable securities, is anticipated to fund the Company’s operations for at least 12 months beyond the date of issuance of the consolidated financial statements. The Company will need to expend substantial resources for research and development, including costs associated with the clinical testing of its product candidates and will need to obtain additional financing to fund its operations and to conduct trials for its product candidates. The Company will seek to finance future cash needs through equity offerings, future grants, corporate partnerships and product sales. The Company has never been profitable and has incurred significant operating losses in each year since inception. Cash requirements may vary materially from those now planned because of changes in the Company’s focus and direction of its research and development programs, competitive and technical advances, patent developments, regulatory changes or other developments. Additional financing will be required to continue operations after the Company exhausts its current cash resources and to continue its long-term plans for clinical trials and new product development. There can be no assurance that any such financing can be obtained by the Company, or if obtained, what the terms thereof may be, or that any amount that the Company is able to raise will be adequate to support the Company’s working capital requirements until it achieves profitable operations. If adequate additional working capital is not secured when needed, the Company may be required to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible and/or suspend or curtail planned research programs. Any of these actions could materially harm the Company’s business and prospects. The outbreak of COVID-19 has evolved into a global pandemic. The extent of the impact of COVID-19 on the Company’s operational and financial performance will depend on certain developments, including the duration and spread of the outbreak, impact on clinical studies, employee or industry events, and effect on suppliers and manufacturers, or impact on the healthcare systems, all of which are uncertain and cannot be predicted. The Company has experienced and may continue to experience constrained supplies of product candidates or, with respect to the Company’s clinical trials, delays in enrollment, site initiation, participant dosing, distribution of clinical trial materials, study monitoring and data analysis that could materially adversely impact the Company’s business, results of operations and overall financial performance in future periods. Any such delays to the Company’s planned clinical timelines for KVD900 and KVD824 could also impact the use and sufficiency of existing cash reserves, and the Company may be required to raise additional capital earlier than previously planned. The Company may be unable to raise additional capital if and when needed, which may result in further delays or suspension of our development plans. The extent to which COVID-19 may impact the Company’s financial condition, results of operations or cash flows is uncertain. The impact of COVID-19 could have a material adverse impact on the Company’s operations and will continue to be monitored closely.

Description of Business and Basis of Presentation

12 Months Ended

Apr. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Description of Business and Basis of Presentation

Note 1. Description of Business and Basis of Presentation

KalVista Pharmaceuticals, Inc. (together with its subsidiaries, “KalVista” or the “Company”) is a clinical stage pharmaceutical company focused on the discovery, development and commercialization of small molecule protease inhibitors for diseases with significant unmet need. The Company’s first product candidates are inhibitors of plasma kallikrein being developed for two indications: hereditary angioedema (“HAE”) and diabetic macular edema (“DME”). The Company applies its insights into the chemistry of proteases and, with current programs, the biology of the plasma kallikrein system, to develop small molecule inhibitors with high selectivity, potency and bioavailability that it believes will make them successful treatments for HAE and DME.

KalVista has created a structurally diverse portfolio of oral plasma kallikrein inhibitors and advanced multiple drug candidates into clinical trials in order to create best-in-class oral therapies for both HAE and DME. The Company is currently evaluating KVD900 in a Phase 2 clinical study as a potential on-demand therapy for acute HAE attacks, which is expected to complete in the second half of 2020. KVD824 is KalVista’s next oral program to be developed for HAE, and the Company plans to commence a Phase 2 clinical trial intended to evaluate KVD824 as a twice-daily potential oral prophylactic treatment for HAE in the second half of 2020. In the case of DME, the Company is initially developing a plasma kallikrein inhibitor which is administered directly into the eye and anticipates ultimate development of orally delivered drugs.

The KVD001 program, which was the lead DME candidate, as well as KalVista’s planned future oral DME programs were subject to an option agreement with Merck Sharpe & Dohme Corp. (“Merck”) entered into in 2017 (the “Option Agreement”). Under the terms of the Option Agreement, Merck had a defined period following receipt of a clinical data package including the results of the Phase 2 trial for KVD001, which were announced in December 2019, to determine whether to exercise its option to acquire KVD001 and to maintain its option on the oral DME programs. In February 2020, Merck notified the Company that those options would not be exercised. As a result, KalVista has retained all the rights and intellectual property that were subject to the Option Agreement, Merck has no further rights or obligations to the Company and the Company has no obligations to Merck.

The Company’s headquarters is located in Cambridge, Massachusetts, with research activities located in Porton Down, United Kingdom and Boston, Massachusetts.

The Company has devoted substantially all of its efforts to research and development, including clinical trials of its product candidates. The Company has not completed the development of any product candidates. Pharmaceutical drug product candidates, like those being developed by the Company, require approvals from the U.S. Food and Drug Administration (“FDA”) or foreign regulatory agencies prior to commercial sales. There can be no assurance that any product candidates will receive the necessary approvals and any failure to receive approval or delay in approval may have a material adverse impact on the Company’s business and financial results. The Company has not yet commenced commercial operations. The Company is subject to a number of risks and uncertainties similar to those of other life science companies developing new products, including, among others, the risks related to the necessity to obtain adequate additional financing, to successfully develop product candidates, to obtain regulatory approval of product candidates, to comply with government regulations, to successfully commercialize its potential products, to the protection of proprietary technology and to the dependence on key individuals.

The Company has funded its operations primarily through the issuance of stock and the Option Agreement. As of April 30, 2020, the Company had an accumulated deficit of $121.6 million and cash, cash equivalents and marketable securities totaling $67.7 million. The Company’s working capital, primarily cash and marketable securities, is anticipated to fund the Company’s operations for at least 12 months beyond the date of issuance of the consolidated financial statements.

The Company will need to expend substantial resources for research and development, including costs associated with the clinical testing of its product candidates and will need to obtain additional financing to fund its operations and to conduct trials for its product candidates. The Company will seek to finance future cash needs through equity offerings, future grants, corporate partnerships and product sales.

The Company has never been profitable and has incurred significant operating losses in each year since inception. Cash requirements may vary materially from those now planned because of changes in the Company’s focus and direction of its research and development programs, competitive and technical advances, patent developments, regulatory changes or other developments. Additional financing will be required to continue operations after the Company exhausts its current cash resources and to continue its long-term plans for clinical trials and new product development. There can be no assurance that any such financing can be obtained by the Company, or if obtained, what the terms thereof may be, or that any amount that the Company is able to raise will be adequate to support the Company’s working capital requirements until it achieves profitable operations. If adequate additional working capital is not secured when needed, the Company may be required to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible and/or suspend or curtail planned research programs. Any of these actions could materially harm the Company’s business and prospects.

The outbreak of COVID-19 has evolved into a global pandemic. The extent of the impact of COVID-19 on the Company’s operational and financial performance will depend on certain developments, including the duration and spread of the outbreak, impact on clinical studies, employee or industry events, and effect on suppliers and manufacturers, or impact on the healthcare systems, all of which are uncertain and cannot be predicted. The Company has experienced and may continue to experience constrained supplies of product candidates or, with respect to the Company’s clinical trials, delays in enrollment, site initiation, participant dosing, distribution of clinical trial materials, study monitoring and data analysis that could materially adversely impact the Company’s business, results of operations and overall financial performance in future periods. Any such delays to the Company’s planned clinical timelines for KVD900 and KVD824 could also impact the use and sufficiency of existing cash reserves, and the Company may be required to raise additional capital earlier than previously planned. The Company may be unable to raise additional capital if and when needed, which may result in further delays or suspension of our development plans. The extent to which COVID-19 may impact the Company’s financial condition, results of operations or cash flows is uncertain. The impact of COVID-19 could have a material adverse impact on the Company’s operations and will continue to be monitored closely.