By Mary Welch
SuperGen Inc. said its anticancer drug, RFS 2000 - now in Phase III for solid tumors - may be active in a number of hematological diseases and showed positive preliminary results in a Phase II study.
"The results are so promising that we're going to rev up the [Phase II] trial as soon as possible," said Joseph Rubinfeld, CEO of San Ramon, Calif.-based SuperGen. "This is an old drug that's quite unique. It's exciting to see that it may have activity in leukemias that are hard to treat. Plus, this just reinforces our belief that RFS 2000 should have broad utility in the anticancer area."
The company, which presented the results at the American Society of Hematology (ASH) meeting in Miami, reported that, of the first 10 patients treated with RFS 2000, five have responded with hematologic remission. The disease of four of the patients was characterized as chronic myelo-monocytic leukemia (CMML) and the six others as Philadelphia chromosome-negative, a myelodysplastic syndrome (MDS) disease.
RFS 2000 is a second-generation oral topoisomerase-I inhibitor. It is a semi-synthetic derivative of a naturally occurring plant alkaloid with cancer-killing properties, and is extracted from the bark and leaves of the camptotheca acuminata tree in China.
The patients undergoing Phase II tests at the M.D. Anderson Cancer Center, in Houston, have a hypo-proliferative disorder of the blood marrow, which includes myelodysplastic syndrome (MDS) and chronic myelo-monocytic leukemia.
"These are genetic diseases, genetic failures," said Rubinfeld, who co-founded Amgen Inc., of Thousand Oaks, Calif., in 1980. "One in every six people in the U.S. are prone to it and 10,000 to 15,000 people each year get it. It's the luck of the draw if you have the missing gene."
Once diagnosed, patients die usually within the year.
First-Quarter 2000 Launch 'Reasonable,' Says CEO
RFS 2000 is in Phase III tests for pancreatic cancer in 30 sites, and the company expects to file a new drug application by the end of next year. "Analysts say it'll be on the shelves the first quarter of 2000," said Rubinfeld. "That's reasonable."
SuperGen's stock (NASDAQ:SUPG) closed Tuesday at $6.75, up $0.125.
In other news from the ASH meeting:
* Aastrom Biosciences Inc., of Ann Arbor, Mich., reported results from one clinical study showing the AastromReplicell System increased the number of cells available for transplant and could enable similar engraftment times to those seen when a larger dose of unexpanded cells is available and used. In another trial, the AastromReplicell System reduced the required dose of peripheral blood stem cells (PBSC) and corresponding number of blood apheresis procedures in cancer patients who had undergone extensive chemotherapy. Results from these two trials, as well as two others, will be used to support European marketing efforts later this year.
* Aronex Pharmaceuticals Inc., of The Woodlands, Texas, and the University of Texas M.D. Anderson Cancer Center, in Houston, presented early data on Atragen to treat acute promyelocytic leukemia. Atragen is a liposomal formulation of all-trans retinoic acid (ATRA). In the study, 10 of the 15 patients achieved clinical remission, a rate similar to that seen with oral ATRA. In addition, seven of seven patients were PCR negative when evaluated at three months. Nine of the 10 patients in clinical remission who continually received Atragen remained in that state for a median period of nine months, which is in sharp contrast to those observed following monotherapy with oral ATRA. A PCR analysis is a sensitive molecular test of a bone marrow sample to measure the presence of residual leukemic cells in patients who are in clinical remission.
* Hemosol Inc., of Toronto, reported that its T cell culture medium, XLCM, can be used to grow large quantities of activated natural killer (NK) cells, which then possess anti-tumor activity against several cancer cells grown in the laboratory. In addition, bone marrow progenitor cells spared damaged by the activated NK cells are also stimulated to proliferate.
* NeXstar Pharmaceuticals Inc., of Boulder, Colo., reported that Phase I and Phase II trials evaluating DaunoXome, a liposomal anticancer product, showed significant activity against life-threatening hematological malignancies, specifically in lymphoma. DanuoXome is a liposomal anticancer product indicated as front-line chemotherapy for advanced HIV-associated Kaposi's sarcoma. Its active ingredient is the anthracycline daunorubicin, encased in a liposome. * Mission-Control Molecules Send Signals Downstream