Verrica Pharmaceuticals · VP-102 · 2020 – 2026

What happened to the glass ampule the FDA flagged in 2020?

In 2020 the FDA pointed to a comparator's ampule-crushing device. By 2026 Verrica's 10-K lists a design patent on its own “ampule crush tool.” Verrica's 8-Ks in between do not mention one.

EphemerisX Research · Published October 7, 2026 · 5 source documents · 1 min read

Short answer

The ampule stayed, and a crushing tool appeared. In 2020 the FDA noted that the Levulan Kerastick uses a “Krusher” device to break its ampule; the 2026 10-K says YCANTH's applicator “contains a sealed glass ampule” and lists a design patent on Verrica's own “proprietary ampule crush tool.”

What the evidence shows

In July 2020 the FDA asked for A test for the crushing force of the glass ampule FDA · Jul 13, 2020 · p. 12, quoted the company's finding that users may struggle to break the glass ampule due to the amount of force required FDA · Jul 13, 2020 · p. 15, and noted that the Levulan Kerastick includes the Kerastick Krusher device as a means of breaking the ampule prior to administration FDA · Jul 13, 2020 · p. 15. It added: The design of the Levulan Kerastick product may inform how you address the break force issues identified during your human factors product development. FDA · Jul 13, 2020 · p. 16

In November 2020 Verrica reported We have also received feedback from the FDA on our Human Factors study protocol 8-K · Nov 9, 2020, and that a U.S. design patent application protecting the design of Verrica’s VP-102 applicator device received an allowance 8-K · Nov 9, 2020. It resubmitted the application on December 23, 2020 8-K · Feb 17, 2021.

The product was approved: On July 21, 2023, YCANTH (VP-102) (cantharidin) 0.7% topical solution was the first product approved by the FDA for the treatment of molluscum 10-K · Mar 11, 2026. The 2026 10-K describes the applicator: Our applicator contains a sealed glass ampule providing long-term room temperature stability 10-K · Mar 11, 2026. It lists one issued United States design patent covering the design of our proprietary ampule crush tool 10-K · Mar 11, 2026, which will expire on April 11, 2038 10-K · Mar 11, 2026.

Assembly is still by hand: To date, all assembly of our single-use precision applicators has been done using manual processes. 10-K · Mar 11, 2026

None of Verrica's 8-K filings here, from July 2020 to September 2022, mentions a crush tool or the Krusher. 8-K · searched The 2026 10-K names neither Sterling nor Piramal, and does not mention human factors, a Type A meeting or a CRL. 10-K · searched

The human factors thread continued into the second letter: What were the human factor comments the second letter said would follow?

Follow the thread

What did the FDA's first letter on VP-102 object to?The Kerastick Krusher
What were the “Human Factor comments” the FDA's second letter said would follow separately?FDA feedback on the Human Factors protocol
How did VP-102 get from a third FDA letter to approval in July 2023?Approved July 21, 2023

This investigation connects to

What happens after a second FDA Complete Response Letter?Cross-investigation · Divergent outcome · with Aldeyra Therapeutics, CorMedix, Outlook Therapeutics, Replimune
What happens when an FDA letter turns on a contract manufacturer, not the drug?Cross-investigation · Shared concern · with CorMedix

The documents, by date

The passages quoted

FDA Complete Response Letter, July 13, 2020 · page 12

The proposed drug product specification does not include test to assure the drug product can be safety and accurately expelled onto the lesion area and avoid the adjacent healthy skin. The specification for the final assembled drug product should be revised to include the following: a. A test for the crushing force of the glass ampule. b. A leakage test after ampule crushing to assure there is no drug leakage at release and during shelf-life. c. A droplet test to demonstrate that the users are capable of dispensing various amount of drug product as needed to the affected skin area while avoiding the adjacent healthy skin.

Open at the source →

FDA Complete Response Letter, July 13, 2020 · page 15

We also reviewed your April 10, 2020 threshold/comparative analyses with Eskata and Levulan Kerastick; products with some similarities to the proposed product in this review. We determined that the Levulan Kerastick has a different user interface than your proposed product because the Levulan Kerastick includes the Kerastick Krusher device as a means of breaking the ampule prior to administration. This difference may impact performance of the critical task of breaking the ampule. Furthermore, with respect to the comparative analyses to the Eskata product, we note postmarketing medication error cases that report accidental exposure to patient and health care professionals when using the product. Given some of the similar design attributes with your proposed product, we are concerned that accidental exposure can occur with cantharidin topical solution, which may present a different risk. As such, we have determined that a leveraging approach for your proposed product is not appropriate and the residual risk with your product is unacceptable.

Open at the source →

FDA Complete Response Letter, July 13, 2020 · page 15

there is a potential that users will struggle to break the glass ampule due to the amount of force required. There is risk that some users may remove the paperboard sleeve in order to try and break the glass ampule. There is also potential for users to utilize other means to break the ampule if they are unable to generate enough force with their hands.”

Open at the source →

FDA Complete Response Letter, July 13, 2020 · page 16

The design of the Levulan Kerastick product may inform how you address the break force issues identified during your human factors product development.

Open at the source →

Verrica Pharmaceuticals Form 8-K, filed July 14, 2020

None of Verrica's 8-K filings here, from July 2020 to September 2022, mentions a crush tool or the Krusher.

Searched the whole document for: crush, Krusher. None found.

Open the document →

Verrica Pharmaceuticals Form 8-K, filed November 9, 2020

Also in August 2020, a U.S. design patent application protecting the design of Verrica’s VP-102 applicator device received an allowance from the United States Patent and Trademark Office (USPTO). The resulting United States design patent (US D900,312) was granted in October 2020.

Open at the source →

Verrica Pharmaceuticals Form 8-K, filed November 9, 2020

We have also received feedback from the FDA on our Human Factors study protocol, and believe we have clear alignment on the path forward to resubmit the NDA, which we anticipate in the first quarter of 2021.

Open at the source →

Verrica Pharmaceuticals Form 8-K, filed February 17, 2021

As previously announced, the FDA issued a Complete Response Letter requesting additional Chemistry, Manufacturing and Controls (CMC) information as well as Human Factors validation in July 2020. Verrica resubmitted the NDA for VP-102 for the treatment of molluscum on December 23, 2020.

Open at the source →