This summary highlights selected information appearing elsewhere
or incorporated by reference into this prospectus and may not contain all of the information that you need to consider in making
your investment decision. You should read this prospectus, the applicable prospectus supplement and any related free writing prospectus
that we have authorized for use in connection with this offering carefully, including the risks and uncertainties included herein
under the heading “Risk Factors” beginning on page 7 in this prospectus and incorporated by reference from our most
recent Annual Report on Form 10-K and our most recent Quarterly Report on Form 10-Q, before making an investment decision.
We are a late-stage biopharmaceutical company
focused on the development of novel, first-in-class pharmaceuticals to address the medical needs of patients with kidney and vascular
disease. Our product candidate, vonapanitase, is a recombinant human elastase that we are developing to improve vascular access
outcomes in patients with chronic kidney disease, or CKD, undergoing or preparing for hemodialysis, a lifesaving treatment that
cannot be conducted without a functioning vascular access. We believe the data from our completed Phase 2 and Phase 3 clinical
trials of vonapanitase in patients undergoing creation of an arteriovenous fistula support that a one-time, local application of
vonapanitase during surgical creation of a radiocephalic fistula for hemodialysis may improve secondary patency (time to fistula
abandonment) and fistula use for hemodialysis, thereby improving patient outcomes and reducing the burden on patients and the healthcare
system. We are currently conducting our second Phase 3 trial, PATENCY-2, which is evaluating vonapanitase in radiocephalic fistulas,
our initial indication. Following our review of the complete data sets from our first Phase 3 trial, PATENCY-1, and discussions
with the U.S. Food and Drug Administration, or FDA, we amended the protocol for the PATENCY-2 trial in the first quarter of 2017.
The protocol amendment reordered the existing endpoints for this ongoing trial, establishing secondary patency (time to fistula
abandonment) and fistula use for hemodialysis as co-primary endpoints. The protocol amendment also increased the planned enrollment
for this trial from 300 to 500 patients which we subsequently increased to 600 patients in the second quarter of 2017. The increased
sample size of 600 patients for the PATENCY-2 trial provides power to detect the differences observed in the PATENCY-1 trial, with
a p-value ≤0.05, for secondary patency (time to fistula abandonment) and fistula use for hemodialysis of 88% and 98%, respectively.
We received written confirmation from the FDA that, if PATENCY-2 is successful in showing statistical significance (p≤0.05)
on each of the co-primary endpoints, the PATENCY-2 trial together with data from previously completed studies would provide the
basis for a Biologics License Application, or BLA, submission as a single pivotal study, in which case no additional studies would
need to be conducted. Vonapanitase also received a Breakthrough Therapy designation from the FDA in May 2017 for hemodialysis vascular
access. The FDA awards Breakthrough Therapy designations to expedite the development and review of investigational drugs that are
intended to treat serious or life-threatening conditions when preliminary clinical evidence indicates that the treatment may offer
a substantial improvement over currently available therapies on one or more clinically significant endpoints. We expect to complete
enrollment for the PATENCY-2 trial in the first quarter of 2018 and to report top-line data in the first quarter of 2019. If the
PATENCY-2 trial is successful, we expect to submit a BLA in 2019.
We commenced business operations in June 2001
and incorporated in March 2006. Our operations to date have been limited to organizing and staffing our company, business planning,
raising capital, undertaking preclinical studies and clinical trials of vonapanitase, protecting our intellectual property and
providing general and administrative support for these operations. To date, we have not generated any product revenue and have
primarily financed our operations through the private placement of our equity securities, business development activities, convertible
note financings, and our initial public offering, or IPO, completed in October 2014.
As of March 31, 2017, we had received an aggregate
of $174.5 million in net proceeds comprised of $94.0 million from the issuance of private equity securities, $7.7 million from
the issuance of convertible notes, $10.0 million from business development activities, $0.2 million from government grants, $62.5
million from our IPO and $0.1 million from the sale of common stock under our at-the-market, or ATM, program with Cowen and Company,
We have never been profitable and have incurred
net losses in each year since inception. As of March 31, 2017, we had an accumulated deficit of $166.3 million and our net loss
for the three months ended March 31, 2017 was $6.5 million. We expect to incur significant expenses and increasing operating losses
for the foreseeable future. We expect our research and development expenses to increase as we continue the clinical trials of,
and seek regulatory approval for, vonapanitase. If we obtain regulatory approval for vonapanitase, we expect to incur significant
commercialization expenses related to product sales, marketing, manufacturing and distribution. Furthermore, we expect that our
general and administrative costs will increase as we grow and operate as a public company. As a result, we will need to generate
significant revenue if we are to achieve profitability, and we may never be able to do so.
Prior to the sale of our Series A Convertible
Preferred Stock, we believed that our cash and cash equivalents and available-for-sale investments as of March 31, 2017 would be
sufficient to fund our operating expenses and capital expenditure requirements into the third quarter of 2018. We closed our $22
million Series A Convertible Preferred Stock transaction on August 2, 2017 and, when including net proceeds from the sale of our
Series A Convertible Preferred Stock along with our cash and cash equivalents and available-for-sale investments as of March 31,
2017, we believe we will have sufficient funds to cover our operating expenses and capital expenditure requirements into the fourth
quarter of 2019, thus allowing us to complete enrollment of patients in our second Phase 3 trial of vonapanitase in radiocephalic
fistulas, to fund our chemistry, manufacturing and controls, or CMC, activities and to obtain results from our second Phase 3 trial.