Note 1 - Business	3 Months Ended
Mar. 31, 2018
Notes to Financial Statements
Business Description and Basis of Presentation [Text Block]	1. Business We are a commercial-stage biotechnology company focused on improving the lives of patients by developing best-in-class treatments that 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 cancer or pain. On August 9, 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 - HT3 receptor antagonist that utilizes Heron’s Biochronomer ® polymer-based 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. On November 9, 2017, our second commercial product, CINVANTI ® (aprepitant) injectable emulsion (“CINVANTI”), was approved by the FDA. 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 and nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy (MEC). CINVANTI is an intravenous formulation of aprepitant, a substance P/neurokinin- 1 (“NK 1 ”) receptor antagonist. CINVANTI is the only IV formulation of an NK 1 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 polysorbate 80 or any other synthetic surfactant. We commenced commercial sales of CINVANTI in the U.S. in January 2018. HTX- 011, which utilizes Heron’s Biochronomer ® polymer-based drug delivery technology, is an investigational, long-acting, extended-release formulation of the local anesthetic bupivacaine in a fixed-dose combination with the anti-inflammatory meloxicam for the prevention of postoperative pain. By delivering sustained levels of both a potent anesthetic and a local anti-inflammatory agent directly to the site of tissue injury, HTX- 011 was designed to deliver superior pain relief while reducing the need for systemically administered pain medications such as opioids, which carry the risk of harmful side effects, abuse and addiction. In March 2018, Heron reported positive topline results from EPOCH1 and EPOCH2, its pivotal Phase 3 studies of HTX- 011 in bunionectomy and hernia repair, respectively. All primary and key secondary endpoints were achieved in these studies. Furthermore, HTX- 011 is the only long-acting local anesthetic to demonstrate in Phase 3 studies significantly reduced pain and opioid use compared to bupivacaine solution, the current standard-of-care local anesthetic for postoperative pain control, through 72 hours. HTX- 011 was well tolerated in both studies, with a safety profile comparable to placebo and bupivacaine solution. HTX- 011 continues to be investigated in ongoing Phase 2 studies in breast augmentation and total knee arthroplasty. HTX- 011 was granted Fast Track Designation from the FDA in the fourth quarter of 2017. In the second half of 2018, Heron expects to file an NDA to the FDA for HTX- 011. We have incurred significant operating losses and negative cash flows from operations. As of March 31, 2018, our accumulated deficit was $834.1 million, and we had $113.9 million in cash, cash equivalents and short-term investments. In April 2018, we received net cash proceeds of $168.7 million from a public offering of our common stock. As of March 31, 2018, our pro-forma cash, cash equivalents and short-term investments, adjusting for the April 2018 public offering, was $282.6 million. Based on our current operating plan and projections, management believes that available cash, cash equivalents and short-term investments are sufficient to fund operations 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

We are a commercial-stage biotechnology company focused on improving the lives of patients by developing best-in-class treatments that 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 cancer or pain.

August 9, 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

HT3

receptor antagonist that utilizes Heron’s Biochronomer

polymer-based 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.

November 9, 2017,

our

second

commercial product, CINVANTI

(aprepitant) injectable emulsion (“CINVANTI”), was approved by the FDA. 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 and nausea and vomiting associated with initial and repeat courses of moderately emetogenic cancer chemotherapy (MEC). CINVANTI is an intravenous formulation of aprepitant, a substance P/neurokinin-

(“NK

”) receptor antagonist. CINVANTI is the only IV formulation of an NK

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 polysorbate

or any other synthetic surfactant. We commenced commercial sales of CINVANTI in the U.S. in

January 2018.

HTX-

011,

which utilizes Heron’s Biochronomer

polymer-based drug delivery technology, is an investigational, long-acting, extended-release formulation of the local anesthetic bupivacaine in a fixed-dose combination with the anti-inflammatory meloxicam for the prevention of postoperative pain. By delivering sustained levels of both a potent anesthetic and a local anti-inflammatory agent directly to the site of tissue injury, HTX-

011

was designed to deliver superior pain relief while reducing the need for systemically administered pain medications such as opioids, which carry the risk of harmful side effects, abuse and addiction.

March 2018,

Heron reported positive topline results from

EPOCH1

and

EPOCH2,

its pivotal Phase

studies of HTX-

011

in bunionectomy and hernia repair, respectively. All primary and key secondary endpoints were achieved in these studies. Furthermore, HTX-

011

is the only long-acting local anesthetic to demonstrate in Phase

studies significantly reduced pain and opioid use compared to bupivacaine solution, the current standard-of-care local anesthetic for postoperative pain control, through

hours. HTX-

011

was well tolerated in both studies, with a safety profile comparable to placebo and bupivacaine solution. HTX-

011

continues to be investigated in ongoing Phase

studies in breast augmentation and total knee arthroplasty. HTX-

011

was granted Fast Track Designation from the FDA in the

fourth

quarter of

2017.

In the

second

half of

2018,

Heron expects to file an NDA to the FDA for HTX-

011.

We have incurred significant operating losses and negative cash flows from operations. As of

March 31, 2018,

our accumulated deficit was

$834.1

million, and we had

$113.9

million in cash, cash equivalents and short-term investments. In

April 2018,

we received net cash proceeds of

$168.7

million from a public offering of our common stock. As of

March 31, 2018,

our pro-forma cash, cash equivalents and short-term investments, adjusting for the

April 2018

public offering, was

$282.6

million. Based on our current operating plan and projections, management believes that available cash, cash equivalents and short-term investments are sufficient to fund operations for at least

one

year from the date this Quarterly Report on Form

-Q is filed with the U.S. Securities and Exchange Commission (“SEC”).