Novel Cancer-Targeting “Cornell Dot” Nanoparticle Approved for First-In-Human Clinical Trial

“Cornell Dots” — brightly glowing nanoparticles — may soon be used to light up cancer cells to aid in diagnosing and treating cancer. The U.S. Food and Drug Administration (FDA) has approved the first clinical trial in humans of the new technology. It is the first time the FDA has approved using an inorganic material in the same fashion as a drug in humans.

“Cornell Dots” (or “C dots”) — brightly glowing nanoparticles — may soon be used to light up cancer cells to aid in diagnosing and treating cancer. The U.S. Food and Drug Administration (FDA) has approved the first clinical trial in humans of the new technology. It is the first time the FDA has approved using an inorganic material in the same fashion as a drug in humans.

Michelle Bradbury, M.D., Ph.D., Clinician-Scientist, Neuroradiology Service, Memorial Sloan-Kettering Cancer Center; Assistant Professor, Radiology, Weill Cornell Medical College; Lead Study Investigator

Researchers at Memorial Sloan-Kettering Cancer Center’s Nanotechnology Center, along with collaborators at Cornell University and Hybrid Silica Technologies, have received approval for their first Investigational New Drug Application (IND) from the FDA for an ultrasmall silica inorganic nanoparticle platform for targeted molecular imaging of cancer, which may be useful for cancer treatment in the future. Center researchers are about to launch their first-in-human clinical trial in melanoma patients using this first-of-its-kind inorganic nanoparticle to be approved as a drug. “This is a very exciting and important first step for this new particle technology that we hope will ultimately lead to significant improvements in patient outcomes and prognoses for a number of different cancers,” said Michelle Bradbury, M.D., Ph.D., a clinician-scientist on Memorial Sloan-Kettering’s Neuroradiology Service and an assistant professor of radiology at Weill Cornell Medical College, who is the lead investigator of the study, along with Snehal Patel, M.D., a surgeon on Memorial Sloan-Kettering’s Head and Neck Service, who is a co-principal investigator.

“This is a very exciting and important first step for this new particle technology that we hope will ultimately lead to significant improvements in patient outcomes and prognoses for a number of different cancers.”

— Michelle Bradbury, M.D., Ph.D., lead investigator of the study and clinician-scientist on Memorial Sloan-Kettering’s Neuroradiology Service and an assistant professor of radiology at Weill Cornell Medical College

C dots were initially developed as optical probes at Cornell University, Ithaca, by Ulrich Wiesner, Ph.D., a professor of materials science and engineering who, along with Hybrid Silica Technologies, the supplier of C dots, has spent the past eight years precisely engineering these particles. C dots are silica spheres less than 8 nanometers in diameter that enclose several dye molecules. (A nanometer is one-billionth of a meter, about the length of three atoms in a row.) The silica shell, essentially glass, is chemically inert and small enough to pass through the body and out in the urine. For clinical applications, the dots are coated with polyethylene glycol so the body will not recognize them as foreign substances.

C dots were subsequently modified at Memorial Sloan-Kettering for use in PET (positron emission tomography) imaging. C dots are tiny silica spheres that contain dye that glows three times more brightly than simple free dyes when excited by light of a specific wavelength. C dots can “light up” cancer cells, and act as tumor tracers for tracking the movement of cells and assisting in the optical diagnosis of tumors near the skin surface. The attachment of a radioactive label produces a new generation of multimodal (PET-optical) particle probes that additionally enable deeper detection, imaging, and monitoring of drug delivery using three-dimensional PET techniques.

Ulrich Wiesner, Ph.D. (left), a Cornell University Professor of Materials Science & Engineering, works with graduate students Jennifer Drewes & Kai Ma to characterize the size & brightness of C dots in their Bard Hall lab. (Photo: Jason Koski/University Photography)

C dots can be tailored to any particle size. Previous imaging experiments in mice conducted by the Memorial Sloan-Kettering team showed that particles of a very small size (in the 5 to 7 nanometer range) could be retained in the bloodstream and efficiently cleared through the kidneys after applying a neutral surface coat. More recently, the research team molecularly customized C dots to create a new particle platform, or probe, that can target surface receptors or other molecules expressed on tumor surfaces and that can be cleared through the kidneys.

Using PET scans, C dots can be imaged to evaluate various biological properties of the tumors, including tumor accumulation, spread of metastatic disease to lymph nodes and distant organs, and treatment response to therapy. The information gained from imaging tumors targeted with this multimodal platform may also assist physicians in defining tumor borders for surgery, and improving real-time visualization of small vascular beds, anatomic channels, and neural structures during surgery.

The purpose of this trial is to evaluate the distribution, tissue, uptake, and safety of the particles in humans by PET imaging. This study will provide data that will serve as a baseline to guide the design of future surgical and oncologic applications in the clinic. “The use of PET imaging is an ideal imaging technology for sensitively monitoring very small doses of this new particle probe in first-in-human trials,” added Steven Larson, M.D., Chief of Memorial Sloan-Kettering’s Nuclear Medicine Service.

Memorial Sloan-Kettering nanochemist Oula Penate Medina, Ph.D., notes that “this is an important trial in that it will help to answer a number of key questions regarding future potential applications of this multimodal system. Once the door has been opened, new and emerging fields, such as targeted drug delivery, can be investigated. We expect that these particles can be adapted for multiple clinical uses, including the early diagnosis and treatment of various cancers, as well as for sensing changes in the microenvironment.”

“This clinical trial is the culmination of a longstanding collaborative effort with our colleagues at Cornell and Hybrid Silica Technologies, as well as a testament to our own institutional colleagues here at the Center,” Dr. Bradbury said. “With the support of many, in particular the Office of Clinical Research, we’ve pushed to translate the C dots from a laboratory idea to our first FDA IND-approved inorganic nanomedicine drug product to be tested in the clinic,” Dr. Bradbury said.

The work was funded in part by the Clinical and Translational Science Center, Weill Cornell Medical College, the Cornell Nanobiology Center, and the National Institutes of Health (NIH) Small-Animal Imaging Research Program (SAIRP). In addition to Drs. Bradbury, Penante-Medina, Larson, Patel, and Wiesner, the following Memorial Sloan-Kettering investigators contributed to and/or supported this work: Pat Zanzonico, Ph.D.; Heiko Schöder, M.D.; Elisa De Stanchina, Ph.D.; Hedvig Hricak, M.D., Ph.D., Chair of the Department of Radiology; as well as Hooisweng Ow, Ph.D., of Hybrid Silica Technologies, Inc.; Memorial Sloan-Kettering’s Office of Clinical Research; and the Cyclotron Core.

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Exelixis Reports Promising Interim Data From Ovarian Cancer Patients Treated With XL184

Exelixis reports promising interim data from ovarian cancer patients treated with XL184, including:  a  32% confirmed response rate per RECIST in patients with platinum-resistant or platinum-sensitive disease, and a 64% overall week-12 disease control rate.

Ignace Vergote, M.D., Ph.D., Head, Department of Obstetrics & Gynecology and Gynecologic Oncology, Catholic University Hospital, Leuven, Belgium

Exelixis, Inc.  today reported interim data from the cohort of patients with advanced epithelial ovarian cancer, primary peritoneal, or fallopian tube carcinoma treated with XL184 in an ongoing phase 2 adaptive randomized discontinuation trial (RDT) [1]. Ignace Vergote, M.D., Ph.D., Head of the Department of Obstetrics and Gynecology and Gynecologic Oncology at the Catholic University Hospital Leuven, Leuven, Belgium, will present the data in the Molecular-Targeted Therapies-Clinical Trials poster session (Abstract #407) on Thursday, November 18th, at the 22nd EORTC-NCI-AACR [2] Symposium on Molecular Targets and Cancer Therapeutics, being held in Berlin, Germany.

XL184 Activity in Patients with Ovarian Cancer

XL184 is an oral, potent inhibitor of MET, VEGFR2 and RET. MET overexpression has been observed in advanced ovarian cancer, and anti-VEGF pathway agents have shown clinical benefit in ovarian cancer patients. For these reasons, co-targeting of the MET and VEGF signaling pathways using XL184 may represent a promising treatment strategy.

As of the November 1, 2010 cut-off date, a total of 51 patients were enrolled into the ovarian cancer cohort, with 31 evaluable for response, and 41 evaluable for safety. The median number of prior systemic treatments was 2. Tumor shrinkage was observed in 30 of 37 (81%) patients with measurable metastatic lesions. Of 31 patients evaluable for response per RECIST (Response Evaluation Criteria In Solid Tumors), 10 (32%) achieved a confirmed partial response (PR). Stable disease (SD) was reported in 15 patients (48%) including 3 patients who achieved unconfirmed PRs. The overall week-12 disease control rate (DCR)(complete responses + partial responses + stable disease responses = DCR) was 64%.

Upon subset analysis, 5 of 17 platinumrefractory or –resistant patients (29%) evaluable for response per RECIST achieved a confirmed PR. SD was reported in 7 patients (41%) including 2 patients with unconfirmed PRs. The week-12 DCR was 59% in platinum-resistant/refractory patients. Durable responses have been observed, including 2 patients with platinum-refractory or resistant disease who remain on study for 34+ and 36+ weeks, and 3 patients with platinum-sensitive disease on study for 24, 24+, and 28+ weeks. Some patients have experienced reductions in the ovarian cancer blood marker CA125, but in general no clear concordance between CA125 changes and tumor shrinkage has been observed.

Safety data are available for 49 patients who had at least 6 weeks of follow-up. The most common grade greater-than or equal to 3 adverse events, regardless of causality were PPE (Palmar-Plantar Erythrodysesthesia) syndrome (also referred to as “hand-foot syndrome”) (12%), diarrhea (7%), fatigue, vomiting (each 5%), nausea, rash, abdominal pain, hypertension, and hypomagnesemia (each 2%).

“The activity of XL184 in women with both platinum-sensitive and platinum-resistant/refractory disease is unique and encouraging. The response rate and overall disease control rate of this oral agent are impressive especially in the group of patients with platinum refractory/resistant ovarian cancer, and compare favorably to other targeted and systemic agents in development,” said, Dr. Vergote. “I believe these encouraging data warrant further evaluation of XL184 in ovarian cancer.”

Michael M. Morrissey, Ph.D., President & Chief Executive Officer, Exelixis, Inc.

“The high response rate in patients with ovarian cancer is reflective of the broad anti-tumor activity of XL184 observed in multiple tumor types to date,” said Michael M. Morrissey, Ph.D., president and chief executive officer of Exelixis. “The data from the RDT underscore the novel and differentiated clinical activity of XL184 in diverse tumor indications with predominance of either soft tissue or bone involvement.”

To access the clinical data poster mentioned in this press release, please visit www.exelixis.com.

Broad Clinical Activity of XL184 – Randomized Discontinuation Trial

XL184 has demonstrated anti-tumor activity in 9 of 12 indications studied to date. In ongoing trials, compelling activity has been observed in medullary thyroid cancer, glioblastoma, and clear cell renal cancer. In the RDT, XL184 is being evaluated in nine different tumor types, with clear signals of activity in six: prostate, ovarian, hepatocellular, breast, non-small cell lung cancer and melanoma. The adaptive RDT design allowed for rapid simultaneous assessment of the activity of XL184 across nine different tumor indications. As of the November 1, 2010 cut-off date, a total of 397 patients have been enrolled into the nine disease-specific cohorts, with 273 evaluable for response, and 312 evaluable for safety. Of 273 patients evaluable for response per RECIST, 39 achieved a PR (either confirmed or unconfirmed) and 100 had SD at week 12. The week-12 DCR for the overall population was 49%, with the highest rates occurring in hepatocellular cancer (75%), castration-resistant prostate cancer (71%), ovarian cancer (64%), melanoma (45%), non-small cell lung cancer (42%) and breast cancer (42%). Of note, a breast cancer patient with evidence of bone metastasis on bone scan demonstrated evidence of resolution on bone scan accompanied by 29% reduction in tumor size. XL184 has been generally well tolerated with a consistent adverse event profile across the nine different RDT tumor types.

About XL184

XL184, an inhibitor of tumor growth, metastasis and angiogenesis, simultaneously targets MET and VEGFR2, key kinases involved in the development and progression of many cancers, including ovarian cancer. It has recently been shown in preclinical models that treatment with selective inhibitors of VEGF signaling can result in tumors that are more invasive and aggressive compared to control treatment. In preclinical studies, upregulation of MET has been shown to occur in concert with development of invasiveness after selective anti-VEGF therapy, and may constitute a mechanism of acquired or evasive resistance to agents that target VEGF signaling. Accordingly, treatment with XL184 in similar preclinical studies resulted in tumors that were less invasive and aggressive compared to control or selective anti-VEGF treatment. Therefore, XL184 has the potential for improving outcomes in a range of indications, including those where selective anti-VEGF therapy has shown minimal or no activity.

About Exelixis

Exelixis, Inc. is a development-stage biotechnology company dedicated to the discovery and development of novel small molecule therapeutics for the treatment of cancer. The company is leveraging its biological expertise and integrated research and development capabilities to generate a pipeline of development compounds with significant therapeutic and commercial potential for the treatment of cancer. Currently, Exelixis’ broad product pipeline includes investigational compounds in phase 3, phase 2, and phase 1 clinical development. Exelixis has established strategic corporate alliances with major pharmaceutical and biotechnology companies, including Bristol-Myers Squibb Company, sanofi-aventis, GlaxoSmithKline, Genentech (a wholly owned member of the Roche Group), Boehringer Ingelheim, and Daiichi-Sankyo. For more information, please visit the company’s web site at http://www.exelixis.com.

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1/Rosner GL, Stadler W, Ratain MJ. et. al.  Randomized discontinuation design: Application to cytostatic antineoplastic agents. J Clin Oncol 20:4478-4484, 2002.  Pursuant to this design, all patients receive the investigational drug for an initial period of time. Patients with standard radiologic tumor shrinkage within that timeframe would continue investigational therapy, while those with radiologic progression or unacceptable toxicity would discontinue therapy. All patients with radiologic stable disease after the initial therapy period are then randomized to continuing or discontinuing therapy in a double-blind placebo-controlled manner. This is an enrichment strategy in which patients with the end point of interest are preferentially enrolled in the randomized portion and in which the heterogeneity of the randomized population is decreased. These two factors result in an increased power for detecting a clinically relevant difference and decrease the number of patients exposed to placebo. Importantly, the enrichment is driven by the properties of the investigational drug as opposed to clinical prognostic factors identified in historical untreated patients or patients treated with a different class of agents. In addition, the statistical behavior of the trial is not highly dependent on investigators’ assumptions regarding the “no dose effect” (i.e., non-receipt of drug = no effect)  for time to progression or stable disease rate, and thus effectively deals with uncertainty in this variable. Finally, patients may find such a trial design more appealing, resulting in brisk accrual.

2/EORTC [European Organisation for Research and Treatment of Cancer, NCI [National Cancer Institute], AACR [American Association for Cancer Research].

Avax Technologies Announces Initiation of Clinical Study With Autologous Ovarian Cancer Vaccine

AVAX Technologies, Inc. (OTC Market:AVXT.OB) today announces it has received FDA approval to begin enrollment into a Phase I-II clinical trial of OVax® for patients with advanced, chemotherapy-refractive ovarian cancer. [For a copy of the clinical trial inclusion/exclusion criteria refer to “OVax®: A Feasibility Study Using a DNP-Modified Autologous Ovarian Tumor Cell Vaccine as Therapy in Ovarian Cancer Patients After Relapse.”]. The study will be performed in collaboration with Cancer Treatment Centers of America, Inc (CTCA). It will be centered in the CTCA hospital in Zion, Illinois, although patients also will be referred from other CTCA hospitals in Tulsa and Philadelphia, and its out-patient clinic in Seattle.

Up to 42 eligible patients with stage III or IV ovarian carcinoma will be enrolled. These patients’ cancers will have progressed despite initial surgery and chemotherapy and failed to respond to one or two salvage chemotherapy regimens. They will undergo debulking surgery, and tumor tissue will be sent to AVAX for production of vaccine. Post-operatively, they will receive intraperitoneal chemotherapy with a taxane and then will be enrolled into the protocol.

Three doses of OVax will be tested, and each of the three doses will be analyzed for immunological efficacy with the goal of optimizing the dose for treatment of patients in future trials.

‘We are enthusiastic about receiving FDA clearance to start this important clinical trial and with the opportunity it affords us to collaborate with CTCA,’ stated Dr. David Berd, Chief Medical Officer of AVAX. ‘Clearly, better treatments for ovarian cancer are needed and we hope that OVax will eventually find its place as a relatively non-toxic therapeutic alternative for these patients. This alliance with CTCA will allow us to expand the therapeutic utility of the AC Vaccine platform along with our ongoing Phase I/II program in non-small cell lung cancer and our recently launched Phase III pivotal registration study in melanoma (MVALDI).’

As part of the business collaboration CTCA has made an up-front payment of $250,000 and will begin to make monthly payments of $25,000 upon the initiation of production of vaccines at AVAX’s Philadelphia manufacturing facility.

‘We are very excited to be part of a new chapter in the fight against ovarian cancer,’ said Dr. Edgar Staren, Chief Medical Officer at Cancer Treatment Centers of America. ‘Ovarian cancer is a very complex cancer that is often resistant to chemotherapy, radiation and surgery. At Cancer Treatment Centers of America, our commitment to cancer patients is to help fight their cancer with the most advanced medical technology available. This partnership with AVAX gives hope to ovarian cancer patients who are told far too often that there is nothing more that can be done for them. This treatment option will work well with our unique integrative care model that combines state-of-the-art traditional medicine with scientifically-based complementary therapies such as aggressive nutritional management and support, naturopathic medicine, physical therapy, mind-body medicine and spiritual support to go beyond treating the tumor and supporting the needs of the whole person – all under one roof.’

About the AC Vaccine Therapeutic

The AC Vaccine is an immunotherapy prepared by attaching a small chemical to the patient’s tumor cells in a process known as haptenization. This hapten modification allows the tumor cells to stimulate a T cell-based immune response to a patients own tumor cells. An early indicator of T cell immune activity is Delayed Type Hypersensitivity (DTH).

An understanding of what AVAX calls the immunopharmacology of the AC Vaccines is critical to their effective use. AVAX believes that the optimal dose, schedule of administration, and route of administration of human cancer vaccines must be established before they enter advanced phase studies, and that some competing vaccine technologies have failed because their developers ignored one or more of these parameters in early phase development. The optimum schedule and best route of administration (intradermal) to be used for OVax were determined by extensive phase I-II studies of MVax. The latest phase I-II trial was completed last year and the results will be presented at the 2008 [Annual] meeting of the American Society of Clinical Oncology (ASCO).”

[Quoted Source: “AVAX Technologies Announces Initiation of Clinical Study with Autologous Ovarian Cancer Vaccine (OVax®),” BusinessWire news release dated April 9, 2008.]

Comment: The OVax®vaccine clinical trial carries great promise. The trial will combine three potent approaches to battling ovarian cancer: (i) debulking surgery, (ii) intraperitoneal chemotherapy with a taxane drug, and (iii) a custom made vaccine created from the ovarian cancer survivor’s own tumor. Please watch the video below regarding the OVax® vaccine for ovarian cancer.