First autologous cellularized scaffold approved by FDA for cartilage defects of the knee

Vericel Corporation announced the FDA approval of an autologous cellularized scaffold for the repair of symptomatic, full-thickness cartilage defects of the knee in adult patients.

Perspective from James N. Gladstone, MD

The first FDA-approved product that applies the process of tissue engineering to grow cells on scaffolds, each Maci (Vericel Corporation) implant is composed of a patient’s cells that are expanded and placed onto a bioresorbable porcine-derived collagen membrane that is implanted over the area where the defective or damaged tissue was removed, according to a press release.

“It’s not prone to overgrowth because it does not have a separate fibrous layer on the surface and it is biodegradable,” Tom Minas, MD, MS, professor of orthopedic surgery at Harvard Medical School and director of the cartilage repair center at the Brigham and Women’s Hospital, told Healio.com/Orthopedics. “It is biodegradable, so the membrane is used basically as a carrier for the cells and the collagen membrane eventually dissolves and disappears, leaving the cells that have been grown and multiplied in the defect that has been transplanted to fill it.”

A company press release noted the approval was based on the SUMMIT, a 2-year prospective, multicenter, randomized, open-label, parallel-group study, that demonstrated a statistically significant greater improvement in KOOS pain and function scores among patients who underwent treatment with the implant compared with patients who underwent microfracture. According to Minas, research also showed patients with cartilage defects of the knee who underwent treatment with the implant experienced clinical benefits in overall efficacy data in an extension study out to 5 years.

“[Using] the KOOS score and using a 10-point minimum improvement as a significant clinical improvement for patients, [researchers] found that the response rate was 88% in the Maci group and 68% in the microfracture group for a single defect on the femoral surface,” Minas said. “They found that those results were durable to 5 years with the same improvement out over 5 years without any deterioration. It is an effective, durable treatment out to 5 years and it offers technical ease and more predictability of a good repair tissue response.”

According to the release, the amount of Maci administered depends on the size of the cartilage defect and multiple implants can be used if there are more than one defect. Administration should be performed by a surgeon specifically trained in the use of the implant, the release noted.

“Bringing an important new therapy to orthopedic surgeons and patients is a significant milestone for Vericel, and I would like to thank the FDA for working closely with us to make Maci available for these patients,” Nick Colangelo, president and chief executive officer of Vericel, said in a company press release. “We believe that the introduction of Maci, along with investments to expand our commercial organization and implement new patient support programs, positions Vericel to generate significant growth in 2017 and beyond.”

References:

www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm533153.htm?source=govdelivery&utm_medium=email&utm_source=govdelivery

http://investors.vcel.com/releasedetail.cfm?ReleaseID=1004125

Disclosure: Minas is a consultant for Vericel.

Perspective

James N. Gladstone, MD

The beauty of Maci is that you are putting a 3-D construct into the cartilage defect. The hope is Maci will more easily and readily create hyaline cartilage — the type of cartilage that makes up articular surfaces. The cartilage cells embedded in the biologic scaffold will hopefully develop, mature and lay down their extracellular matrix in a more structurally and architecturally sound fashion. Within this porcine collagen matrix, the cells may be distributed more evenly, can produce their matrix more evenly and can produce their extracellular matrix in a 3-D manner that more readily resembles normal hyaline cartilage rather than being placed as a monolayer suspension of cells, as it has been up until now.

I think from a biologic point-of-view, it adds the advantages of being a biologic scaffold and being more mechanically sound and durable than a puddle of cells. From a surgical point of view, it is going to save a tremendous amount of time. We are entering a new age in terms of cartilage transplantation, which is wonderful. There are a couple of other products on the market that are going through phase 3 FDA clinical trials that hopefully will be approved in the next few years.

I think what is yet to be fully proven is whether this technique of doing the cartilage transplant will have better results than the traditional way. The big issues are whether it can be done reproducibly and whether the cartilage has the appropriate architectural structure that is critical for its function. It needs to develop in a columnar orientation in order to provide shock absorption and protection to the joint and its underlying bone.

James N. Gladstone, MD

The Mount Sinai Hospital

Co-chief of the Sports Medicine Service

Associate Professor of Orthopaedic Surgery

Department of Orthopaedic Surgery

Icahn School of Medicine at Mount Sinai

Disclosures: Gladstone reports he has no relevant financial disclosures.