Aldoxorubicin…….Treatment of cancer …HIV-derived Kaposi’s Sarcoma, pancreatic cancer and for the treatment of soft tissue sarcoma.

Aldoxorubicin

http://www.ama-assn.org/resources/doc/usan/aldoxorubicin.pdf

 in phase 3

(E)-N'-(1-((2S,4S)-4-(((2R,4S,5S,6S)-4-amino-5-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)oxy)-2,5,12-trihydroxy-7-methoxy-6,11-dioxo-1,2,3,4,6,11-hexahydrotetracen-2-yl)-2-hydroxyethylidene)-6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanehydrazide hydrochloride

1H-Pyrrole-1-hexanoic acid, 2,5-dihydro-2,5-dioxo-, (2E)-2-[1-[(2S,4S)-4-[(3-amino-
2,3,6-trideoxy-α-L-lyxo-hexopyranosyl)oxy]-1,2,3,4,6,11-hexahydro-2,5,12-trihydroxy-
7-methoxy-6,11-dioxo-2-naphthacenyl]-2-hydroxyethylidene]hydrazide

N'-[(1E)-1-{(2S,4S)-4-[(3-amino-2,3,6-trideoxy-α-L-lyxo-hexopyranosyl)oxy]-2,5,12-
trihydroxy-7-methoxy-6,11-dioxo-1,2,3,4,6,11-hexahydrotetracen-2-yl}-2-
hydroxyethylidene]-6-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)hexanohydrazide
MOLECULAR FORMULA C37H42N4O13

MOLECULAR WEIGHT 750.7

SPONSOR CytRx Corp.

CODE DESIGNATION INNO-206

CAS REGISTRY NUMBER 1361644-26-9

CAS:  151038-96-9 (INNO-206); 480998-12-7 (INNO-206 HCl salt),  1361644-26-9

hydrochloride

CAS:  151038-96-9

Chemical Formula: C37H42N4O13

Exact Mass: 750.27484

Molecular Weight: 750.75

Certificate of Analysis:	View current batch of CoA
QC data:	View NMR, View HPLC, View MS
Safety Data Sheet (MSDS):	View Material Safety Data Sheet (MSDS)

In vitro protocol:	Clin Cancer Res. 2012 Jul 15;18(14):3856-67
In vivo protocol:	Clin Cancer Res. 2012 Jul 15;18(14):3856-67. Invest New Drugs. 2010 Feb;28(1):14-9. Invest New Drugs. 2012 Aug;30(4):1743-9. Int J Cancer. 2007 Feb 15;120(4):927-34.
Clinical study:	Expert Opin Investig Drugs. 2007 Jun;16(6):855-66.

Aldoxorubicin (INNO-206): Aldoxorubicin, also known as INNO-206,  is the 6-maleimidocaproyl hydrazone derivative prodrug of the anthracycline antibiotic doxorubicin (DOXO-EMCH) with antineoplastic activity. Following intravenous administration, doxorubicin prodrug INNO-206 binds selectively to the cysteine-34 position of albumin via its maleimide moiety. Doxorubicin is released from the albumin carrier after cleavage of the acid-sensitive hydrazone linker within the acidic environment of tumors and, once located intracellularly, intercalates DNA, inhibits DNA synthesis, and induces apoptosis. Albumin tends to accumulate in solid tumors as a result of high metabolic turnover, rapid angiogenesis, hyervasculature, and impaired lymphatic drainage. Because of passive accumulation within tumors, this agent may improve the therapeutic effects of doxorubicin while minimizing systemic toxicity.

“Aldoxorubicin has demonstrated effectiveness against a range of tumors in both human and animal studies, thus we are optimistic in regard to a potential treatment for Kaposi’s sarcoma. The current standard-of-care for severe dermatological and systemic KS is liposomal doxorubicin (Doxil®). However, many patients exhibit minimal to no clinical response to this agent, and that drug has significant toxicity and manufacturing issues,” said CytRx President and CEO Steven A. Kriegsman. “In addition to obtaining valuable information related to Kaposi’s sarcoma, this trial represents another opportunity to validate the value and viability of our linker technology platform.” The company expects to announce Phase-2 study results in the second quarter of 2015.

Kaposi’s sarcoma is an orphan indication, meaning that only a small portion of the population has been diagnosed with the disease (fewer than 200,000 individuals in the country), and in turn, little research and drug development is being conducted to treat and cure it. The FDA’s Orphan Drug Act may grant orphan drug designation to a drug such as aldoxorubicin that treats a rare disease like Kaposi’s sarcoma, offering market exclusivity for seven years, fast-track status in some cases, tax credits, and grant monies to accelerate research

INNO-206 is an anthracycline in early clinical trials at CytRx Oncology for the treatment of breast cancer, HIV-related Kaposi’s sarcoma, glioblastoma multiforme, stomach cancer and pancreatic cancer. In 2014, a pivotal global phase 3 clinical trial was initiated as second-line treatment in patients with metastatic, locally advanced or unresectable soft tissue sarcomas. The drug candidate was originally developed at Bristol-Myers Squibb, and was subsequently licensed to KTB Tumorforschungs. In August 2006, Innovive Pharmaceuticals (acquired by CytRx in 2008) licensed the patent rights from KTB for the worldwide development and commercialization of the drug candidate. No recent development has been reported for research that had been ongoing for the treatment of small cell lung cancer (SCLC).

INNO-206 is a doxorubicin prodrug. Specifically, it is the 6-maleimidocaproyl hydrazone of doxorubicin. After administration, the drug candidate rapidly binds endogenous circulating albumin through the acid sensitive EMCH linker. Circulating albumin preferentially accumulates in tumors, bypassing uptake by other non-specific sites including the heart, bone marrow and the gastrointestinal tract. Once inside the acidic environment of the tumor cell, the EMCH linker is cleaved and free doxorubicin is released at the tumor site. Like other anthracyclines, doxorubicin inhibits DNA and RNA synthesis by intercalating between base pairs of the DNA/RNA strand, thus preventing the replication of rapidly-growing cancer cells. It also creates iron-mediated free oxygen radicals that damage the DNA and cell membranes. In 2011, orphan drug designation was assigned in the U.S. for the treatment of pancreatic cancer and for the treatment of soft tissue sarcoma.

CytRx Corporation (NASDAQ:CYTR) has  announced it has initiated a pivotal global Phase 3 clinical trial to evaluate the efficacy and safety of aldoxorubicin as a second-line treatment for patients with soft tissue sarcoma (STS) under a Special Protocol Assessment with the FDA. Aldoxorubicin combines the chemotherapeutic agent doxorubicin with a novel linker-molecule that binds specifically to albumin in the blood to allow for delivery of higher amounts of doxorubicin (3.5 to 4 times) without several of the major treatment-limiting toxicities seen with administration of doxorubicin alone.

According to a news from Medicalnewstoday.com; CytRx holds the exclusive worldwide rights to INNO-206. The Company has previously announced plans to initiate Phase 2 proof-of-concept clinical trials in patients with pancreatic cancer, gastric cancer and soft tissue sarcomas, upon the completion of optimizing the formulation of INNO-206. Based on the multiple myeloma interim results, the Company is exploring the possibility of rapidly including multiple myeloma in its INNO-206 clinical development plans.

According to CytRx's website, In preclinical models, INNO-206 was superior to doxorubicin with regard to ability to increase dosing, antitumor efficacy and safety. A Phase I study of INNO-206 that demonstrated safety and objective clinical responses in a variety of tumor types was completed in the beginning of 2006 and presented at the March 2006 Krebskongress meeting in Berlin. In this study, doses were administered at up to 4 times the standard dosing of doxorubicin without an increase in observed side effects over historically seen levels. Objective clinical responses were seen in patients with sarcoma, breast, and lung cancers.

 INNO-206 - Mechanism of action:

According to CytRx's website, the proposed mechanism of action is as the follow steps: (1) after administration, INNO-206 rapidly binds endogenous circulating albumin through the EMCH linker. (2) circulating albumin preferentially accumulates in tumors, bypassing uptake by other non-specific sites including heart, bone marrow and gastrointestinal tract; (3) once albumin-bound INNO-206 reaches the tumor, the acidic environment of the tumor causes cleavage of the acid sensitive linker; (4) free doxorubicin is released at the site of the tumor.

INNO-206 - status of clinical trials:

CytRx has announced  that, in December 2011, CytRx initiated its international Phase 2b clinical trial to evaluate the preliminary efficacy and safety of INNO-206 as a first-line therapy in patients with soft tissue sarcoma who are ineligible for surgery. The Phase 2b clinical trial will provide the first direct clinical trial comparison of INNO-206 with native doxorubicin, which is dose-limited due to toxicity, as a first-line therapy. (source:http://cytrx.com/inno_206, accessed date: 02/01/2012).

   

Results of Phase I study:

In a phase I study a starting dose of 20 mg/m2 doxorubicin equivalents was chosen and 41 patients with advanced cancer disease were treated at dose levels of 20–340 mg/m2 doxorubicin equivalents . Treatment with INNO-206 was well tolerated up to 200 mg/m2 without manifestation of drug-related side effects which is a ~3-fold increase over the standard dose for doxorubicin (60 mg/kg). Myelosuppression and mucositis were the predominant adverse effects at dose levels of 260 mg/m2 and became dose-limiting at 340 mg/m2. 30 of 41 patients were assessable for analysis of response. Partial responses were observed in 3 patients (10%, small cell lung cancer, liposacoma and breast carcinoma). 15 patients (50%) showed a stable disease at different dose levels and 12 patients (40%) had evidence of tumor progression. (source: Invest New Drugs (2010) 28:14–19)

References

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