Alpha Tau to Conduct Trial of Alpha DaRT Technology In Patients With Recurrent Squamous Cell Carcinoma

Dermoscopy. Squamous cell carcinoma: © DermNet

"I think in general, it's important for us to be running clinical trials for skin cancer patients. There are a number of excellent options available to them, but there are always subsets of patients that for whom standard of care, unfortunately, is not sufficient. I think there's a clear and key need for these types of trials to be done, and I look forward to many more Alpha DaRT trials in different cutaneous spaces," said Robert Den, MD, the chief medical officer of Alpha Tau Medical.

Den and Alpha Tau are seeking investigators specializing in recurrent squamous cell carcinoma (SCC) who are interested in participating in the organization's ongoing Recurrent SCC Treatment with Alpha DaRT Radiation Therapy, or ReSTART, trial (NCT05323253).

Den previously spoke with Dermatology Times to discuss the role of Alpha DaRT technology in skin cancer and dermatologic applications. Alpha DaRT harnesses alpha particle-emitting atoms to specifically attack cancer cells while sparing healthy tissue. By directly damaging cancer cell DNA with double-strand breaks, it effectively kills them.

Recruitment

The ongoing trial is actively recruiting in locations across the United States, Israel, and Canada. A list of recruiting clinical centers can be accessed on Alpha Tau's website. To date, Alpha Tau has engaged Mohs surgeons, dermatologists, head and neck surgeons, and radiation oncologies as part of its recruitment strategy.

"As part of our screening process, we are looking for sites that see high volumes of these particular patients," Den said. "We understand that the vast majority of patients with skin cancer do very well with standard first line therapies. However, given the high incidence and prevalence of the cancer, even though the percentage is low, the absolute number of patients available for recruitment on such a trial is quite large."

Primary Trial Endpoints

The trial has 2 co-primary endpoints, the first of which is the overall response rate achieved with Alpha DaRT treatment. Response rate will be measured using Response Evaluation Criteria in Solid Tumors, or RECIST, and will serve as an evaluation of the best overall patient responses.

The second trial endpoint is duration of response 6 months after initial treatment response. Researchers will evaluate both the treatment response and the duration of said response.

Eligibility Criteria

Patients eligible for participation in the trial must have histopathologic confirmation of cutaneous SCC. In addition, they must have failed a first line standard of care treatment, whether it be surgery or radiation therapy. They also must not be indicated for further surgery or standard radiation therapy and are eligible for trial participation in instances where no curative systemic therapy is available. Patients also have to have measurable disease according to RECIST, which should involve tumor depth.

Patients must also be willing to undergo multiple CT scans due to the nature of the trial's evaluation of response. SCC lesion(s) are required to be technically amenable for complete coverage. Patients must have a life expectancy of 12 months or more, normal blood values, and be willing to sign informed consent.

This is based on criteria by which Alpha Tau was given Breakthrough Status by the US Food and Drug Administration for the use of Alpha DaRT technology.

Patients ineligible for the trial include individuals with T-4 disease, extensive perineural spread, and mucosal, anal, vulvar, or penile SCC. Individuals receiving ongoing treatment with systemic immunosuppressive therapy or who exhibit keratoacanthoma histology are also unable to participate.

While individuals previously treated with any anti neoplastic systemic therapy, biological therapy, or immunotherapies they are allowed to be enrolled in the trial, they are required to partake in a 4-week washout period prior to enrollment.

Alpha DaRT Procedure

Each patient in the trial will receive treatment with Alpha DaRT.

A treating physician will identify the tumor and have a pre-planned design for the direction by which the implant will be placed prior to the time the patient enters the procedure room.

"Because it is skin cancer, there is a lot of artistry to it, as opposed to a very rogue way to go, given the different flexibility and different geometry, so every patient's plan is personalized to them," Den said.

Patients undergo this initial procedure under local anesthesia. The physician will insert sources using either a curved or straight needle. All sources are implanted fully sealed, which eliminated the risk of radiation during the procedure itself.

"The physician will use a through and through technique similar or akin to putting a pin through a shirt, where you will enter one side and exit the other side," Den said. "We recommend that the entry and exit points are in normal healthy tissue as opposed to tumor tissue, but if needed for an exophydic tumor, they can be in tumor itself."

Once the physician is satisfied with the placement of the needles, they will then release the sources by pushing forward a plunger, which pushes out a small suture. The Alpha DaRT sources are located on that suture, and each applicator is marked by the number of sources on each suture. Each source is 1 centimeter in length and 0.7 millimeters in diameter.

Once the source is deployed, the physicians will then secure it by placing a small button to protect the underlying skin, and a small surgical microclip, on both sides of the tumor.

The implant is to remain in place for 14 to 21 days. After this period, patients will return to the clinic to have the sources removed. This procedure does not require local anesthesia in most patient cases.

The surgeon will release the surgical microclip from one side of the suture, freeing one end. The other end will have a suture on it with skin being on the other side of it, and the physician will lift the entire suture with the sources directly out of the treated area.

Investigators interested in participating in the ReSTART trial are invited to connect with Alpha Tau for more information and to get started.