Business	9 Months Ended
Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business	1. Business We are a commercial-stage biotechnology company focused on improving the lives of patients by developing best-in-class treatments to address some of the most important unmet patient needs. We are developing novel, patient-focused solutions that apply our innovative science and technologies to already-approved pharmacological agents for patients suffering from pain or cancer. In August 2016, our first commercial product, SUSTOL (granisetron) extended-release injection (“SUSTOL”), was approved by the U.S. Food and Drug Administration (“FDA”). SUSTOL is indicated in combination with other antiemetics in adults for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic chemotherapy (MEC) or anthracycline and cyclophosphamide (AC) combination chemotherapy regimens. SUSTOL is an extended-release, injectable 5-hydroxytryptamine type 3 receptor antagonist that utilizes our proprietary Biochronomer drug delivery technology to maintain therapeutic levels of granisetron for ≥5 days. We commenced commercial sales of SUSTOL in the U.S. in October 2016. In November 2017, our second commercial product, CINVANTI (aprepitant) injectable emulsion (“CINVANTI”) was approved by the FDA. In October 2019, the FDA approved our supplemental New Drug Application (“sNDA”) for CINVANTI to expand the indication and recommended dosage to include the 130 mg single-dose regimen for patients receiving moderately emetogenic cancer chemotherapy (“MEC”). CINVANTI, in combination with other antiemetic agents, is indicated in adults for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy (HEC) including high-dose cisplatin as a single-dose regimen, delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy (MEC) as a single-dose regimen, and nausea and vomiting associated with initial and repeat courses of MEC as a 3-day regimen. CINVANTI is an intravenous (“IV”) formulation of aprepitant, a substance P/neurokinin-1 (“NK₁”) receptor antagonist. CINVANTI is the first and only IV formulation of an NK₁ receptor antagonist indicated for the prevention of acute and delayed nausea and vomiting associated with HEC and nausea and vomiting associated with MEC that is free of synthetic surfactants, including polysorbate 80. We commenced commercial sales of CINVANTI in the U.S. in January 2018. In February 2019, the FDA approved our sNDA for CINVANTI, for IV use, which expanded the administration of CINVANTI beyond the initially approved administration method (a 30-minute IV infusion) to include a 2-minute IV injection. CINVANTI is under investigation for the treatment of Coronavirus Disease 2019 (“COVID-19”) as a daily 2-minute IV injection when added to the current standard of care. In September 2020, our third commercial product, ZYNRELEF (also known as HTX-011) was granted a marketing authorization by the European Commission (“EC”). ZYNRELEF is indicated for the treatment of somatic postoperative pain from small- to medium-sized surgical wounds in adults. The marketing authorization follows the European Medicines Agency’s positive opinion from the Committee for Medicinal Products from Human Use in July 2020. The EC’s centralized marketing authorization is valid for the 27 countries that are members of the European Union (“EU”), and the other countries in the European Economic Area (“EEA”). ZYNRELEF, a non-opioid, is a dual-acting, fixed-dose combination of the local anesthetic bupivacaine with a low dose of the nonsteroidal anti-inflammatory drug meloxicam. It is the first and only extended-release local anesthetic to demonstrate in Phase 3 studies significantly reduced pain and opioid use through 72 hours compared to bupivacaine solution, the current standard-of-care local anesthetic for postoperative pain control. We are currently assessing the evolving global environment for pharmaceuticals and developing a coordinated global marketing strategy, and at this time we anticipate making ZYNRELEF available to patients in Europe during the second half of 2021. HTX-011 (ZYNRELEF in the EU and EEA) is an investigational agent in the United States and Canada. The FDA granted Breakthrough Therapy designation to HTX-011 and the New Drug Application (“NDA”) received Priority Review designation. A Complete Response Letter (“CRL”) was received from the FDA regarding the NDA for HTX-011 in June 2020. The CRL stated that the FDA is unable to approve the NDA in its present form based on the need for additional non-clinical information. Based on the complete review of the NDA, the FDA did not identify any clinical safety or efficacy issues or chemistry, manufacturing and controls issues. There are four non-clinical issues in the CRL, none of which relate to any observed toxicity. Three relate to confirming exposure of excipients in preclinical reproductive toxicology studies, and the fourth relates to changing the manufacturing release specification of the allowable level of an impurity based on animal toxicology coverage. In September 2020, we announced a successful Type A meeting with the FDA in which alignment was reached on the plans for our resubmission of the NDA for HTX-011 for the management of postoperative pain in the fourth quarter of 2020. Our New Drug Submission for HTX-011 for the management of postoperative was accepted by Health Canada in November 2019. We are working to respond to a list of questions received from Health Canada in July 2020, and we anticipate up to a 300-day review period following our responsive submission. HTX-034, our next-generation product candidate for postoperative pain management, is an investigational non-opioid, fixed-dose combination, extended‑release solution of the local anesthetic bupivacaine, the nonsteroidal anti-inflammatory drug meloxicam and an additional agent that further potentiates the activity of bupivacaine. HTX-034 is formulated in the same proprietary polymer as HTX-011 (ZYNRELEF in the EU and EEA). By combining two different mechanisms that each enhance the activity of the local anesthetic bupivacaine, HTX-034 is designed to provide superior and prolonged analgesia. Local administration of HTX-034 in a validated preclinical postoperative pain model resulted in sustained analgesia for 7 days. In May 2020, we initiated a Phase 1b/2 clinical study in patients undergoing bunionectomy of HTX-034. The study initiation followed clearance from the FDA of our Investigational New Drug application for HTX-034 for the treatment of postoperative pain. As of September 30, 2020 we had $258.1 million in cash, cash equivalents and short-term investments. We have incurred significant operating losses and negative cash flows from operations. Management believes that the Company’s existing cash, cash equivalents and short-term investments will be sufficient to meet the Company’s anticipated cash requirements for at least one year from the date this Quarterly Report on Form 10-Q is filed with the U.S. Securities and Exchange Commission (“SEC”).

Business

9 Months Ended

Sep. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Business

We are a commercial-stage biotechnology company focused on improving the lives of patients by developing best-in-class treatments to address some of the most important unmet patient needs. We are developing novel, patient-focused solutions that apply our innovative science and technologies to already-approved pharmacological agents for patients suffering from pain or cancer.

In August 2016, our first commercial product, SUSTOL (granisetron) extended-release injection (“SUSTOL”), was approved by the U.S. Food and Drug Administration (“FDA”). SUSTOL is indicated in combination with other antiemetics in adults for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic chemotherapy (MEC) or anthracycline and cyclophosphamide (AC) combination chemotherapy regimens. SUSTOL is an extended-release, injectable 5-hydroxytryptamine type 3 receptor antagonist that utilizes our proprietary Biochronomer drug delivery technology to maintain therapeutic levels of granisetron for ≥5 days. We commenced commercial sales of SUSTOL in the U.S. in October 2016.

In November 2017, our second commercial product, CINVANTI (aprepitant) injectable emulsion (“CINVANTI”) was approved by the FDA. In October 2019, the FDA approved our supplemental New Drug Application (“sNDA”) for CINVANTI to expand the indication and recommended dosage to include the 130 mg single-dose regimen for patients receiving moderately emetogenic cancer chemotherapy (“MEC”). CINVANTI, in combination with other antiemetic agents, is indicated in adults for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy (HEC) including high-dose cisplatin as a single-dose regimen, delayed nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy (MEC) as a single-dose regimen, and nausea and vomiting associated with initial and repeat courses of MEC as a 3-day regimen. CINVANTI is an intravenous (“IV”) formulation of aprepitant, a substance P/neurokinin-1 (“NK₁”) receptor antagonist. CINVANTI is the first and only IV formulation of an NK₁ receptor antagonist indicated for the prevention of acute and delayed nausea and vomiting associated with HEC and nausea and vomiting associated with MEC that is free of synthetic surfactants, including polysorbate 80. We commenced commercial sales of CINVANTI in the U.S. in January 2018. In February 2019, the FDA approved our sNDA for CINVANTI, for IV use, which expanded the administration of CINVANTI beyond the initially approved administration method (a 30-minute IV infusion) to include a 2-minute IV injection. CINVANTI is under investigation for the treatment of Coronavirus Disease 2019 (“COVID-19”) as a daily 2-minute IV injection when added to the current standard of care.

In September 2020, our third commercial product, ZYNRELEF (also known as HTX-011) was granted a marketing authorization by the European Commission (“EC”). ZYNRELEF is indicated for the treatment of somatic postoperative pain from small- to medium-sized surgical wounds in adults. The marketing authorization follows the European Medicines Agency’s positive opinion from the Committee for Medicinal Products from Human Use in July 2020. The EC’s centralized marketing authorization is valid for the 27 countries that are members of the European Union (“EU”), and the other countries in the European Economic Area (“EEA”). ZYNRELEF, a non-opioid, is a dual-acting, fixed-dose combination of the local anesthetic bupivacaine with a low dose of the nonsteroidal anti-inflammatory drug meloxicam. It is the first and only extended-release local anesthetic to demonstrate in Phase 3 studies significantly reduced pain and opioid use through 72 hours compared to bupivacaine solution, the current standard-of-care local anesthetic for postoperative pain control. We are currently assessing the evolving global environment for pharmaceuticals and developing a coordinated global marketing strategy, and at this time we anticipate making ZYNRELEF available to patients in Europe during the second half of 2021.

HTX-011 (ZYNRELEF in the EU and EEA) is an investigational agent in the United States and Canada. The FDA granted Breakthrough Therapy designation to HTX-011 and the New Drug Application (“NDA”) received Priority Review designation. A Complete Response Letter (“CRL”) was received from the FDA regarding the NDA for HTX-011 in June 2020. The CRL stated that the FDA is unable to approve the NDA in its present form based on the need for additional non-clinical information. Based on the complete review of the NDA, the FDA did not identify any clinical safety or efficacy issues or chemistry, manufacturing and controls issues. There are four non-clinical issues in the CRL, none of which relate to any observed toxicity. Three relate to confirming exposure of excipients in preclinical reproductive toxicology studies, and the fourth relates to changing the manufacturing release specification of the allowable level of an impurity based on animal toxicology coverage. In September 2020, we announced a successful Type A meeting with the FDA in which alignment was reached on the plans for our resubmission of the NDA for HTX-011 for the management of postoperative pain in the fourth quarter of 2020. Our New Drug Submission for HTX-011 for the management of postoperative was accepted by Health Canada in November 2019. We are working to respond to a list of questions received from Health Canada in July 2020, and we anticipate up to a 300-day review period following our responsive submission.

HTX-034, our next-generation product candidate for postoperative pain management, is an investigational non-opioid, fixed-dose combination, extended‑release solution of the local anesthetic bupivacaine, the nonsteroidal anti-inflammatory drug meloxicam and an additional agent that further potentiates the activity of bupivacaine. HTX-034 is formulated in the same proprietary polymer as HTX-011 (ZYNRELEF in the EU and EEA). By combining two different mechanisms that each enhance the activity of the local anesthetic bupivacaine, HTX-034 is designed to provide superior and prolonged analgesia. Local administration of HTX-034 in a validated preclinical postoperative pain model resulted in sustained analgesia for 7 days. In May 2020, we initiated a Phase 1b/2 clinical study in patients undergoing bunionectomy of HTX-034. The study initiation followed clearance from the FDA of our Investigational New Drug application for HTX-034 for the treatment of postoperative pain.

As of September 30, 2020 we had $258.1 million in cash, cash equivalents and short-term investments. We have incurred significant operating losses and negative cash flows from operations. Management believes that the Company’s existing cash, cash equivalents and short-term investments will be sufficient to meet the Company’s anticipated cash requirements for at least one year from the date this Quarterly Report on Form 10-Q is filed with the U.S. Securities and Exchange Commission (“SEC”).