Epizyme Inc., the latest biotech to take advantage of the emerging growth company provision in last year's JOBS Act, filed an S-1 Friday for a proposed $69 million initial public offering (IPO), though the number of shares and share price have not yet been disclosed.

Proceeds from the IPO, along with the firm's cash of $85 million as of March 31, will be used in part to cover the costs of Phase I development of EPZ-5676 in mixed lineage leukemia (MLL), an aggressive subtype of the most common forms of leukemia. The drug is designed to inhibit DOT1L, an enzyme that is misregulated due to a chromosomal translocation, thereby activating the family of genes causing MLL.

The Phase I study started in September and results are expected in the second half of this year. EPZ-5676 is partnered with Summit, N.J.-based Celgene Corp., under a broad epigenetics deal inked last year that brought the small biotech $90 million up front, with the potential for at least $160 million in milestone payments per compound, plus double-digit royalties. Under the terms, Cambridge, Mass.-based Epizyme retains rights to EPZ-5676 in the U.S. (See BioWorld Today, April 26, 2012.)

Funds also will be used to support R&D to build the firm's product platform and advance preclinical candidates for genetically targeted cancers, as well as for working capital and general corporate purposes.

Founded in 2007, Epizyme bases its work on epigenetics, which refers to the influencing of gene expression via modifying the way a DNA sequence is structurally packaged, without altering the sequence itself. The approach has become increasingly popular, as drugs targeting epigenetic enzymes have gained approval – notably histone deacetylase inhibitors such as Istodax (romidepsin, Celgene) and DNA methyltransferase inhibitors such as Vidaza (azacitadine, Celgene) and Dacogen (decitabine, Astex Pharmaceuticals Inc.)

Epizyme's two lead programs are designed to target protein methyltransferases, such as DOT1L in the case of EPZ-5676, and EZH2, the target of EPZ-6438, which is in development for non-Hodgkin's lymphoma patients whose disease has oncongenic point mutations in EZH2. A Phase I/II study testing EPZ-6438 is slated to start later this quarter That drug is partnered with Eisai Inc., of Woodcliff Lake, N.J., and offers Epizyme an option for co-development, co-commercialization and profit-sharing.

In addition to the deals with Celgene and Eisai, Epizyme has racked up a number of collaborations centered on its epigenetics approach, including a 2011 deal with GlaxoSmithKline plc, of London, to discover, develop and commercialize small-molecule inhibitors of HMT, and a recently inked deal with Abbott Park, Ill.-based Abbott to develop a molecular companion diagnostic test for use with EPZ-5676 in MLL.

As of March 31, collaborations had brought in about $120 million in nonequity funding, Epizyme said.

The firm, which plans to seek a Nasdaq listing under the ticker "EPZM," had about 5.6 million shares outstanding at the end of the first quarter. Its largest shareholders include New Enterprise Associates, Kleiner, Perkins, Caufield & Byers, Bay City Capital, Celgene European Investment Co. LLC and MPM Capital. Citigroup, Cowen and Co. LLC and Leerink Swann LLC will act as joint book-running managers for the offering, while JMP Securities LLC and Wedbush Securities Inc. will act as co-managers.

In other financings news:

• Anacor Pharmaceuticals Inc., of Palo Alto, Calif., said it priced a public offering of about 3. 1 million shares at $6.39 per share for gross proceeds of $20 million. Underwriters Cowen and Co. LLC, Canaccord Genuity Inc. and Wedbush Securities Inc. have a 30-day option to purchase up to 15 percent of the shares offered in the public offering to cover overallotments. Net proceeds will be used to support R&D activities, working capital and general corporate purposes. Anacor is working on small-molecule therapeutics derived from its boron chemistry program. The company's stock (NASDAQ:ANAC) gained 37 cents Friday, to close at $6.75.

• Receptos Inc., of San Diego, set a price range for its proposed initial public offering, anticipating selling 4.7 million shares priced between $14 and $16. At the midpoint range, the offering would bring in gross proceeds of $70.5 million. The company filed to go public earlier this month, aiming to raise $86.3 million to support clinical work in multiple sclerosis, inflammatory bowel disease and allergic/immune-mediated disorders. Upon pricing, Receptos' shares would trade on Nasdaq under the ticker "RCPT." (See BioWorld Today, April 8, 2013.)

• ReXceptor Inc., of Cleveland, a spinout of Case Western Reserve, said it has secured $1 .4 million to advance its work in Alzheimer's disease (AD). The arrangement includes the Charles Evans Foundation/Alzheimer's Drug Discovery Award of $500,000 and a $250,000 contribution from BrightFocus as part of a collaboration with the Alzheimer's Drug Discovery Foundation. ReXceptor also received two anonymous investments totaling $450,000 and $200,000 from Case Western. The funding allowed ReXceptor to enter a formal partnership with C2N Diagnostics, which will assist the company with the initiation and coordination of the clinical trial of an AD program licensed from Case Western's Technology Transfer Office and based on discoveries that bexarotene, a medication sold at Targretin for cutaneous T-cell lymphomas, reversed AD symptoms in mice within 72 hours of a single dose of treatment.