Repligen Corp. announced Tuesday that it has initiated twoseparate Phase I/II clinical trials on Replistatin, itsrecombinant platelet factor-4 (rPF4), for inhibiting tumorgrowth in colon carcinoma, metastatic malignant melanoma andrenal cell carcinoma.

The colon carcinoma trial is an open-label study involving nineto 12 patients, who will be infused with varying doses of rPF4.The other open-label trial will enroll from nine to 15 patientswith either metastatic malignant melanoma or renal cellcarcinoma, who will also be infused with different doses of thecompound.

Banking on the fact that rPF4, by blocking angiogenesis (or thedevelopment of new blood vessel networks), is able to deprivesolid growing tumors of their blood supply, Repligen(NASDAQ:RGEN) has already tested the compound in AIDSpatients with Kaposi's sarcoma (KS).

Data from those Phase I trials, in which the volunteers receivedintralesional injections of rPF4, were presented in May at themeeting of the American Society of Clinical Oncology. Repligenis gearing up for a Phase II systemic intravenous infusionstudy in KS patients, which it plans to initiate in late July orearly August, according to Clare Clifford, the company's directorof corporate communications.

As well, the Cambridge, Mass., company started Phase I trialson rPF4 in patients undergoing cardiac catheterization inMarch. The idea is to restore normal coagulation to thosepatients by neutralizing heparin, which is used to temporarilyblock blood coagulation during the surgical procedure.

June seems to be the month for Repligen to get its products intothe clinic. Early this month it started Phase I trials on itstherapeutic AIDS vaccine candidate, RP400c, which is a subunitimmunogen that is specifically directed at generatingneutralizing antibodies to the V3 loop segment of HIV'senvelope protein gp120. Repligen is developing RP400c with itspartner, Merck & Co. The safety trial on HIV-seropositiveindividuals is also intended to evaluate the putative vaccine'sability to enhance both humoral and cellular immune responsesto HIV.

And just last week, Repligen announced that it had started aPhase I safety trial in chronic lung inflammation patients of apotential anti-inflammatory compound it is developing with EliLilly and Co. The compound, m60.1, is a fragment of anantibody to the CD11b integrin, a protein component ofneutrophils that plays a key role in acute tissue injury. Inpreclinical studies it blocked neutrophil binding sites andinhibited the release of tissue-damaging substances.

-- Jennifer Van Brunt Senior Editor

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