HistoSonics, Inc. is a Michigan-based company that is using the non-thermal histotripsy mechanism of focused ultrasound to treat benign prostatic hyperplasia (BPH). Although BPH causes an enlarged prostate, it does not lead to cancer-the unwanted cells need to be removed when they cause irritation or obstruction. Vortx RX is the company's investigational, image-guided, system for treating BPH. A pilot clinical trial is currently underway in North America to test the system’s safety and initial effectiveness.
Q&A With HistoSonics Chairman & CEO Tom Davison, PhD
Q. How did you get involved in starting HistoSonics?
I was introduced to the University of Michigan (UM) Department of Tech Transfer in late 2007. UM asked me to help evaluate several medical device technologies in their patent portfolio, including histotripsy. Because of my experience in therapeutic ultrasound businesses (UltraCision and Sontra), UM asked me to review the histotripsy program to determine whether it should be licensed or had the potential to support a stand-alone business. At the completion of the consulting assignment, I acquired an option to license the histotripsy technology and intellectual property. After several years of planning, HistoSonics was founded in December 2009.
Q. What is the unmet medical need in benign prostatic hyperplasia (BPH)?
BPH was chosen as the best first application for histotripsy after analyzing the markets and technology translation risks for BPH and numerous other possibilities. Our research confirmed an unmet market need for BPH treatment because patients are seeking a less invasive, less morbid, and longer-lasting alternative to traditional therapies. This market is potentially $500 million worldwide. The most important factor in choosing to pursue BPH treatment as the first clinical application for histotripsy was verification of the clinical rationale provided by the extensive translational and preclinical research at UM.
Q. Why histotripsy? Why ultrasound energy?
Histotripsy is a therapeutic ultrasound modality that mechanically homogenizes tissue with highly energized cavitation bubbles. Histotripsy removes and debulks tissue in a manner similar to transurethral resection of the prostate (TURP), the “gold standard” treatment for BPH. Additionally, its non-thermal characteristics significantly reduce unintended tissue injury and inflammation.
Extensive studies clearly supported the clinical rationale for the treatment of BPH with histotripsy tissue ablation, including: 1,2,3
- Immediate relief
- Treatment durability
- Minimal bleeding
- Shorter catheterization duration
- Less pain and discomfort
- No need for opiate pain medication after the procedure
- Economic benefits of improved, long-term efficacy, fewer complications, and an office-based procedure
Q. In general, what is the current status of your company?
After we completed development of the Vortx RX System for BPH treatment, six devices were built (4 for clinical studies and 2 for laboratory research). We received clinical research approvals in the United States and Canada. Pilot clinical studies are underway at three sites.
Q. How many years has the Vortx RX System been in development, and what are its origins?
Development of the Vortx RX system began in December 2009, and the first clinical device was ready by summer 2013. It was preceded by very sophisticated laboratory prototypes that included all of the functions of the system, including 3D surgical planning, precise robotic control, and real time ultrasound imaging.
Q. Why do you want it to be an in-office procedure?
In-office, outpatient BPH procedures are preferred by patients and urologists. Patients prefer a quick return home over enduring the hospital setting. Urologists receive larger reimbursement, and healthcare payers also benefit because costs are significantly less.
Q. What are some of the technical challenges your group has had to overcome to develop the system?
Many technical challenges were overcome during development of the Vortx RX clinical device, leading to many patent applications. The challenges were typical of those encountered when converting a laboratory prototype to a device that can be used on patients in the clinical setting.
Q. What challenges will you have to tackle moving forward?
HistoSonics faces the challenges that all early-stage medical device companies encounter, including efficient patient recruitment for the pilot study, enhancing device design and engineering, pre-market approval, and continued financing of the company.
Q. Tell us about your pilot study that just started.
We have two U.S. sites (25 patients each) and one Canadian site (20 patients). The primary end-points are related to safety, and the secondary end-points include gathering initial efficacy data such as symptom relief and urine flow.
Q. Who are your competitors in BPH treatment, and what are the benefits of your technology over other approaches? How does your technology reduce costs compared to other treatment options for BPH?
Competitors for BPH treatment include:
- Manufacturers who produce products for TURP using electrosurgery and laser devices (80% of market)
- Minimally invasive procedures, including transurethral needle ablation of the prostate (TUNA, performed with radiofrequency ablation) and transurethral microwave thermal therapy (TUMT, performed with microwave ablation) (currently experiencing declining market share)
- Electrosurgical approaches (currently regaining share lost to lasers)
Histotripsy may be able to reproduce the clinical effectiveness of TURP procedures with much less bleeding and patient trauma in an office-based setting. Vortx RX BPH treatment offers economic benefit compared to TURP because TURP is not performed in the urologist’s office. Minimally invasive procedures were adopted for a short time because they were office-based but were later abandoned due to poor long-term outcomes and the fact that they were not well tolerated due to postoperative pain and long catheterization.
1Lake AM, Hall TL, Kieran K, Fowlkes JB, Cain CA, Roberts WW, “Histotripsy: minimally invasive technology for prostatic tissue ablation in an in vivo canine model,” Urology 2008 Sep;72(3):682-6. 2Hall TL, Hempel CR, Wojno, K, Xu Z, Cain CA, Roberts WW, Histotripsy of the prostate: dose effects in the chronic canine model. Urology 2009;74:932-7. 3Hempel CR, Hall TL, Cain CA, Fowlkes JB, Xu Z, Roberts WW, Histotripsy fractionation of prostate tissue: local effects and systemic response in a canine model. J Urol 2011;185:1484-9.