With launch of its Phase III registration studies for Lupus drug blisibimod imminent, Anthera Pharmaceuticals Inc., of Hayward, Calif., priced an underwritten public offering worth $40 million in gross proceeds to support operations as it goes forward.

The planned studies, CHABLIS-SC1 and CHABLIS-SC2, received a green light from the FDA only after Anthera convinced the agency that the drug's Phase IIb miss was due to weak results in the two lower-dose groups.

In addition to enabling Phase III studies of blisibimod in systemic lupus erythematosus, an Anthera spokesperson told BioWorld Today that the offering will provide "an opportunity to accelerate our orphan strategy," with studies of blisibimod in IgA nephropathy.

The offering will consist of 60,606,061 shares of common stock at $0.66 per share. Underwriters have an option to purchase up to 9,090,099 additional shares.

Blisibimod (A-623) is a peptibody antagonist of BAFF, a tumor necrosis factor involved in development of B-cells. Overexpression of BAFF is thought to play a role in systemic lupus erythematosus.

According to Anthera, preclinical studies in transgenic mice showed that overexpression of BAFF was connected with symptoms resembling lupus.

Anthera's Phase IIb study, PEARL-SC, missed its primary efficacy endpoint of clinical improvement at 24 weeks in the Systemic Lupus Erythematosus Responder Index. That analysis used data from pooled dose groups including 100 mg weekly and 200 mg weekly.

The news torpedoed Anthera's stock price, but full results released later suggested that weak numbers in the lower dose groups hobbled the overall outcome of the study. The strongest dose alone, however, gave a statistically significant benefit at 16 weeks (35.4 percent vs. 17 percent, p = 0.04) that was maintained through 24 weeks (41.7 percent vs. 10.4 percent, p < 0.001) in severely affected lupus patients.

Anthera's design for Phase III calls for using the 200-mg weekly dose of blisibimod in patients with active lupus, despite concomitant use of corticosteroids.

Anthera also found in PEARL-SC that a subgroup of severely ill, seropositive lupus patients who were also receiving background corticosteroid therapy had a more pronounced treatment benefit with the 200-mg weekly dose compared to other doses.

Anthera will revisit that subgroup in the Phase III CHABLIS-SC studies.

CHABLIS-SC1 and CHABLIS-SC2 will be placebo-controlled, randomized, double-blind studies assessing efficacy, safety and tolerability of blisibimod in about 400 patients with lupus. The primary efficacy endpoint will be clinical improvement in the Systemic Lupus Erythematosus Responder Index (SRI-8).

Anthera will carry out an interim analysis during the 52-week CHABLIS-SC1 study, and, if all is going well, begin enrollment in CHABLIS-SC2.

Blisibimod also has potential in some B-cell mediated autoimmune diseases, such as IgA nephropathy. Results from PEARL-SC showing reduction in total B-cells and significant improvements in proteinuria suggested that blisibimod could have activity in IgA nephropathy.

Anthera is planning to begin enrollment in a Phase II proof-of-concept trial (BRIGHT-SC) in IgA nephropathy in 2013. The trial will enroll about 48 patients with IgA nephropathy to receive high-dose blisibimod or placebo for eight weeks, followed by a 24-week maintenance period of blisibimod or placebo.

If approved, blisibimod will line up against Benlysta (belimumab, Human Genome Sciences Inc. and GlaxoSmithCline plc), a B lymphocyte stimulator approved by the FDA in March 2011.

Uptake of Benlysta has been slow, but blisibimod may have an edge in that it is delivered subcutaneously, whereas Benlysta is an intravenous infusion. As well, blisibimod targets membrane-bound BAFF, while Benlysta only acts on soluble BAFF. That mechanistic difference could translate to a better treatment effect.

Following the offering, Anthera will have 79,111,870 shares of stock outstanding. Anthera stock (NASDAQ:ANTH) fell 8 cents, or 10.5 percent, to close Friday at 64 cents.

In other financings news:

• Arrowhead Research Corp., of Pasadena, Calif., priced a public offering of about 1.65 million units at $2.12 apiece for about $3.5 million in gross proceeds. Each unit consists of one share of common stock and one warrant to purchase 0.5 of a share of common stock. Net proceeds are expected to support general corporate purposes, including working capital, R&D, clinical trials and capital expenditures. Dawson James Securities Inc. is acting as the sole book-running manager. Arrowhead is developing peptide-drug conjugates in areas such as oncology, obesity and chronic hepatitis B virus. Shares of Arrowhead (NASDAQ:ARWR) closed Friday at $1.99, down 15 cents.

• Auxilium Pharmaceuticals Inc., of Chesterbrook, Pa., priced a $325 million aggregate principal amount of 1.5 percent convertible senior notes due 2018. The company also granted underwriters a 30-day option to purchase up to an additional $25 million. Net proceeds are expected to total about $314.5 – about $338.7 million if the underwriters' option is exercised in full – and will be used to pay the cost of note hedge transactions and for general corporate purposes. Goldman, Sachs & Co. and J.P. Morgan Securities LLC are acting as joint book-running managers for the offering, while Cowen and Co. and RBC Capital Markets are serving as co-managers.

• BG Medicine Inc., of Waltham, Mass., said it entered a common stock purchase agreement with Aspire Capital Fund LLC, in which Aspire committed to purchase up to $12 million of BG's common stock from time to time as directed by BG over the next two years, at prices based on prevailing market prices over a period preceding each sale. BG issued to Aspire 132,743 common shares as consideration for entering the agreement. Net proceeds from any offering will be used for general corporate purposes and working capital requirements. BG develops and commercializes cardiovascular tests.

• DelMar Pharmaceuticals Inc., of Vancouver, British Columbia, said it acquired through a share exchange agreement all of the outstanding shares of Del Mar Pharmaceuticals Ltd., a clinical- and commercial-stage drug development firm with a focus on cancer. Concurrently with the acquisition, DelMar completed the first closing in a private placement consisting of about 6.7 million units of its securities for gross proceeds of $5.4 million. Funds will support drug development activities for VAL-083, a small-molecule chemotherapeutic in Phase I/II testing in glioblastoma multiforme. DelMar is now quoted on the OTCQB under the ticker "BRRY," which will change to "DMPI" on or about Jan. 31.

• OPKO Health Inc., of Miami, priced its offering of $175 million aggregate amount of 3 percent convertible senior notes due 2033 in a private offering, OPKO said it intends to use proceeds for general corporate purposes, including R&D, acceleration of clinical trials, acquisitions of new technologies or business and other business opportunities.

• Transgenomic Inc., of Omaha, Neb., said it entered definitive agreements with a syndicate of institutional and other accredited investors to raise gross proceeds of $8.3 million in a private placement financing. The syndicate comprised new and existing investors, including entities associated with Third Security LLC. Transgenomic agreed to issue an aggregate of 16.6 million shares price at 50 cents apiece, as well as five-year warrants to purchase up to an aggregate of 8.3 million shares at an exercise price of 75 cents per share. Net proceeds will be used for general corporate and working capital purposes, primarily to accelerate commercialization of several of the firm's genetic tests. Lazard Capital Markets LLC served as lead placement agent, while Craig-Hallum Capital Group LLC acted as co-placement agent.