Immunotherapy company Argos Therapeutics has filed plans for a $60 million initial public stock offering to finance late-stage clinical trials on its experimental kidney cancer treatment.

It’s the second IPO filing in two years for the Durham company, which withdrew its plans in 2012 citing market conditions. At that time, Argos had been seeking to raise $65 million to take AGS-003, its kidney cancer immunotherapy, into phase III clinical trials. Enrollment in the AGS-003 trial is already underway.

The IPO filing comes nearly two months after Argos raised another $17.5 million to support the phase III trial, called “ADAPT.” Expanding that series E round brought the total amount of funds from that round to $60 million. Argos had closed that round in August at $42.5 million.

“This funding further strengthens our ability to advance our ADAPT clinical trial,” Jeff Abbey, Argos’ president and CEO said at the time. “ In addition, the company is now better positioned to consider and pursue a range of options to support our global manufacturing and commercialization plans based on the potential of our Arcelis technology platform.”

Those options now include financing studies of AGS-003 and other therapeutic candidates in its drug pipeline through a public stock offering.

A $2 billion market

Argos’s technology, called Arcelis, works by prompting the immune system to fight disease. The company’s first target is metastatic renal cell carcinoma, the most common form of kidney cancer. Argos estimates that the current worldwide market for metastatic renal cell carcinoma is more than $2 billion. Arcelis works by using a sample of the tumor and the patient’s own dendritic cells to create antigen to fight the cancer. That’s the approach taken by Seattle company Dendreon (NASDAQ:DNDN), whose immunotherapy to treat prostate cancer is the only antigen-based immunotherapy approved by the Food and Drug Administration.

Argos says that because these personalized immunotherapies are designed to target specific antigens, they are less likely to be toxic to the patient. But Argos adds that antigen-based immunotherapies may have limited efficacy because they are only able to capture one or a limited number of antigens, which may or may not be present in the patient’s cancer cells. These immunotherapies also do not capture mutated antigens.

AGS-003 isn’t being evaluated on as a standalone cancer treatment. Argos’ phase III trial will study the therapy in combination with Pfizer (NYSE:PFE) drug sunitinib, also known as Sutent. Argos already has a special protocol assessment for AGS-003, essentially the FDA’s review of the design of the clinical trial and agreement on what is sufficient to support a filing for drug approval. The primary endpoint of the trial is overall survival. In phase II studies, median overall survival was 30.2 months. That’s more than twice the median overall survival of 14.7 months in metastatic renal cell carcinoma patients treated with sunitinib or other targeted therapies, according to data collected by the International Metastatic Renal Cell Carcinoma Database Consortium.

A second therapeutic candidate coming from the Arcelis technology, AGS-004, is being studied as an HIV treatment. A phase IIb clinical trial of AGS-004 is being funded entirely by a $39.3 million National Institutes of Health contract.

Argos’ finances

Argos was founded in 1998 as Merix Bioscience, a company based on RNA technology licensed from Duke University. The company has raised more than $263.6 million, a combination of debt and equity financings, government contracts, grants and license and partnering agreements. Venture capital investors include The Aurora Funds, Forbion Capital Partners, Genechem, Intersouth Partners, Lumira Capital and TVM Capital.

For 2012, Argos reported a net loss of $10.5 million. The company’s loss has widened as it ramped up work on the AGS-003 clinical trials. Through the first three quarters of 2013, Argos reported a net loss of $15.9 million.

As of Sept. 30, Argos had cash, cash equivalents and short-term investments totaling $18.2 million and working capital of $18.1 million.

Even if Argos is successful in raising $60 million in its IPO, the company acknowledges it will need to raise additional capital prior to commercialization of AGS-003 or any of its other candidates. On the company’s to-do list is construction of a manufacturing facility to make its immunotherapies. Argos did not say in Monday’s filing how much it would need to complete the AGS-003 trials or how much it would cost to build the manufacturing facility. In its previous IPO filing, Argos estimated it would need $85 million to complete phase III studies and another $25 million for the manufacturing facility.

Argos said it plans to apply to list on the Nasdaq exchange trading under the stock symbol “ARGS.” The company has not yet given a price range for the stock or set an effective date for the registration statement. Enrollment in the phase III trial of AGS-003 is expected in the second half of 2014, Argos said in the filing. Overall survival data is expected in the first half of 2016.