Promising New Radioligand Treatment for Men with Metastatic Prostate Cancer Using Lutetium 177 (177Lu)

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Using small molecules, we are able to target not only the known tumors, but can also treat the unknown tumors.

Physicians and researchers at Weill Cornell Medicine have been utilizing prostate specific membrane antigen (PSMA)-directed radioisotope therapy for more than a decade. Over the years, we have shown that we could use this approach to target the vast majority of prostate cancer tumors (“hitting” essentially all known tumors and avoiding normal organs), demonstrated anti-tumor responses when the J591 antibody is linked to a radioactive particle with a large (single) treatment, and then further improved upon this treatment (while simultaneously reducing the side effects) by dose-fractionation (splitting the dose into two).

Following our lead and with the discovery of new small molecules which also specifically bind to PSMA, European physicians have begun using these compounds tagged with the same radioactive particle. The most common molecule has been termed PSMA-617. They have shown some very nice anti-tumor responses with limited side effects. However, because European laws differ from the U.S., many men are able to pay for treatment outside of the setting of rigorous, organized clinical research studies that clearly define appropriate dosing, efficacy and toxicity.

In January 2017, research was published in the Journal of Nuclear Medicine demonstrating that Lutetium 177 combined with PSMA-617 can reduce the amount of tumors in the body and lead to remission of the cancer as measured by PSA level. Twelve German hospitals reviewed their data and compiled a publication of patients with metastatic prostate cancer who received Lutetium-177 linked to PSMA-617 (177Lu-PSMA-617). Over 18 months, 145 men whose cancer grew despite standard treatments (including abiraterone and/or enzalutamide and chemotherapy) and whose tumors “lit up” on PSMA imaging were treated. While not a proper prospective research study, they were able to determine information about both anti-tumor activity and safety. Most patients who had PSA measured before and after treatment had some decline, with 40% having PSA cut at least in half following a single treatment. Blood counts dropped in less than half (usually to moderate degrees) and some developed dry mouth and/or taste changes. Severe toxicity was rare.

It is encouraging to see that there is a treatment that might lead to reduction in cancer without severe side effects, even in men who previously have received many other lines of treatment. However, both rigorous research as well as access for our patients are current issues. Therefore, we are excited to offer a clinical trial that builds upon our prior experience of anti-PSMA radioimmunotherapy while taking into account the available European data.

This study utilizes the most commonly used molecule, 177Lu-PSMA-617, in a prospective manner. Our prior research has shown that higher doses result in significantly better anti-tumor responses, so one purpose of this study is to perform dose-escalation to determine the safest and most-effective dose without increased side effects. In addition, our research demonstrated that dose-fractionation allowed higher doses with less toxicity, so our treatment schedule will deliver the total dose in 2 fractions.

We look forward to advancing science and also making these treatments available to men in the tri-state area and across the U.S., not just those who can afford to fly to Germany for treatment. At Weill Cornell Medicine and NewYork-Presbyterian, we have an excellent, multidisciplinary team that has led the world in PSMA-targeted radionuclide therapy. We will leverage our combined expertise and experience to translate the exciting knowledge base into true clinical gains for prostate cancer patients.

To learn more about the clinical trial or enroll, click here. Call us at 646-962-2072 to make an appointment or schedule a consultation. 

Using Radiation, Radioimmunotherapy and Radioactive Isotopes such as Lutetium 177 to Treat Prostate Cancer

Radiation is a mainstay in the treatment of prostate cancer. In men with localized prostate cancer (confined to the prostate gland), using radiation can help cure the cancer. In men with advanced disease, radiation can improve survival and help to manage pain.

Radiation can be delivered a variety of different ways. For example, there are external beams that can be used to deliver radiation from an external machine into the prostate, radioactive “seeds” that can be implanted, or ways to inject special radioactive isotopes directly into the bloodstream.

In the United States (U.S.), there are older FDA-approved treatments utilizing radioactive isotopes for men with prostate cancer that has spread to the bones to decrease pain, called samarium-153 (brand name Quadramet) and strontium-89 (Metastron). More recently, a bone-targeted alpha particle called radium-223 (brand name Xofigo®) was approved because it leads to longer overall survival in men with symptomatic metastatic castration-resistant bone metastases. These bone-targeted radioisotopes have been useful because prostate cancer commonly spreads to bone. However, those drugs cannot treat other sites of tumors such as in the prostate, lymph nodes, or lung.

We are also able to use parts of the immune system as a way to deliver radioactive particles or other targeted cancer treatments to the prostate cancer. We have engineered very specific monoclonal antibodies and molecules that will bind only to PSMA, leading to the opportunity for “molecularly targeted” radiotherapy for prostate cancer. When we combine immunotherapy with monoclonal antibodies with radioactive isotopes, we call the treatment approach radioimmunotherapy. Radioimmunotherapy involves attaching a radioactive isotope (such as Lutetium 177) to a cancer-targeting antibody or small molecule that binds only to a specific cancer-related molecule on a tumor cell. This is similar to a “lock and key” scenario, where the antibody or molecule serves as a key that will only recognize a very specific lock (the cancer-related molecule). In prostate cancer, nearly all cells have a specific “lock” that lives on the surface of each cell called prostate-specific membrane antigen (PSMA).

j591_psmaFor nearly 15 years, we have been utilizing a monoclonal antibody known as J591, which is a version of a specific key that will only recognize and enter cells with the specific lock PSMA. We successfully utilized this antibody tagged with small radioactive particles to either visualize or treat prostate cancer tumors within the prostate, bone, lymph nodes, and other sites in the body. Our initial studies demonstrated safety and signaled anti-tumor efficacy. In addition, we showed that the antibody went to virtually all sites of tumors (sometimes discovering new ones) and did not target other normal organs (with the exception of the liver which helps clear the drug from the body). Subsequently, our larger studies have shown responses in larger numbers of patients. In Europe, physicians picked up on our results and Lutetium 177 (also known as Lu-177, 177-Lu or 177 Lutetium) has become a very popular radioactive particle that can be directed to prostate cancer via PSMA. It has been used to kill prostate cancer cells and treat hundreds of prostate cancer patients. This commonly-used approach uses a small molecule which recognizes PSMA to deliver Lu-177 to prostate cancer cells (termed radioligand therapy or radioimmunotherapy therapy).

Lutetium-177 PSMA therapy is associated with a good prostate cancer response and many men travel from all over the world to Europe in order to access this treatment. In the U.S. it is only available via clinical trials, and for more than 10 years, Weill Cornell Medicine and NewYork-Presbyterian have been one of the few centers in the U.S. to offer Lutetium 177 and other targeted treatments using radioactive particles.

Learn more about how this treatment works in this video:

Is Chemo The Best Bladder Cancer Treatment For All?

DR. SCOTT TAGAWA AND DR. BISHOY FALTAS

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The bladder is a muscular organ made up of several layers of cells. This image outlines the bladder, ureters and surrounding vessels.

State-of-the-art cancer care continues to evolve due to advances in all aspects of patient care – including diagnosis, and personalized treatment and management. By incorporating novel diagnostics, systemic therapies, molecular targeted therapies, immunotherapies, and other biotechnological strategies into treatment paradigms, patient outcomes continue to improve along the cancer continuum.

For patients with bladder cancer and other urothelial cancers (cancers of the bladder, renal pelvis and ureter), cisplatin-based chemotherapy remains the standard of care. This is based on decades of research through a series of randomized clinical trials showing that chemotherapy regimens containing cisplatin consistently lead to the best overall survival rates. Importantly, some patients with metastatic urothelial cancer who are treated with cisplatin-based regimens are cured.

However, cisplatin is hard on not just the cancer cells, but the body overall. As a result, not all patients are “fit” for cisplatin. There are standard criteria that are used to define patients for whom cisplatin is not a viable treatment option. These include kidney (renal) function as measured by a blood test and sometimes urine tests, performance status (a measure of how physically functional patients are), hearing loss, nerve damage (neuropathy/numbness), and heart failure. Some of the time, there may be trade-offs. For instance, some patients would trade off the risk of needing a hearing aid for a higher chance of tumor shrinkage (or even cure).

While it is well-known among physicians that not all bladder cancer patients are candidates for this treatment option, questions linger regarding what the best treatment option should be for these patients. To get to the bottom of this question, we reviewed the scientific evidence and Dr. Scott Tagawa recently presented our findings to a large group at the 34th annual Chemotherapy Foundation Symposium (CFS). This conference brought together over 2,000 cancer care clinicians across a multidisciplinary spectrum to provide updates on the most cutting-edge new agents, ongoing clinical trials and emerging developments in cancer treatment and diagnosis.

What did the science show?

According to recent data presented at the 2016 European Society of Medical Oncology (ESMO) meeting, the most common alternative treatment regimen for patients who are well enough to tolerate chemotherapy is the combination of carboplatin and gemcitabine chemotherapies. This was based on the review of data from 1426 patients with advanced urothelial carcinoma who were treated with chemotherapy.

Interestingly, there were some other global trends in the types of chemo prescribed. Centers that treated fewer patients with urothelial cancers were more likely to give alternative (non-cisplatin) chemotherapy to patients that did not meet any standard criteria for being unfit. The most common reason for being deemed unfit for cisplatin was the patient’s current level of kidney function. Unfortunately, data showed that patients who were fit for cisplatin, but received alternative chemotherapy lived much shorter than those who received cisplatin, and none of those patients in the study were alive at the 5-year mark.

One setting where cisplatin-based chemotherapy is very important is in the pre-operative setting where the goal is cure rather than just prolongation of life by months to years. Physicians should be aware of some “tricks of the trade” to optimize kidney function and other parameters to maximize the chance for cisplatin administration and cure. For patients, it’s important to consider at least getting a consultation at a center of excellence before making a treatment decision.

We also recently wrote an editorial in The Lancet outlining the value of immunotherapy for patients with advanced urothelial cancers who are unfit for cisplatin, and in particular checkpoint inhibitor immunotherapy. While not currently FDA-approved for this indication, a study using atezolizumab (Tecentriq) was published in this prestigious journal with a second supportive study utilizing pembrolizumab (Keytruda) presented at the ESMO meeting in October. Both studies used monoclonal antibodies that enable the immune system to become activated and fight cancer, and both demonstrated substantial responses in a subset of patients. Studies of the tumor and surrounding tissue testing for PDL1 expression are able to predict those with a higher likelihood of response, but even those with “negative” testing can respond. Tests of tumor genomics are also able to group tumors into those with a higher likelihood of response, but again, even those in the lower immune responding group can have a long-term response to immune treatment. Ongoing studies are needed to help predict response in a more powerful manner. One issue that we’ve recently examined is the difference in tumor genomics before and after chemotherapy highlighted by Dr. Faltas’ high-impact publication on the clonal evolution of urothelial cancer. Among other things, this highlights the importance of obtaining recent tissue from metastatic sites to gain the most accurate understanding of an individual patient’s tumor biology.

In summary, it is important for physicians to recognize when a patient may or may not safely receive certain chemotherapy regimens, such as cisplatin combinations in the case of urothelial carcinoma. In addition, research is ongoing for patients that are unfit for certain types of chemotherapy to prove whether or not immunotherapy should be used in patients who have not yet received chemotherapy. Several immunotherapy drugs are currently being tested in randomized clinical trials and these include patients that are unfit for cisplatin. Additionally, other drugs such as antibody-drug conjugates or monoclonal antibodies have shown promising activity in patients with advanced urothelial carcinoma, and these studies included patients unfit for cisplatin.