Sumitomo Pharma: AMCHEPRY shows promise in Parkinson’s disease - EXCLUSIVE
AMCHEPRY is indicated for the improvement of motor symptoms in patients
with Parkinson’s disease whose symptoms are not adequately controlled with
existing pharmacological therapies, including levodopa-containing products. The
product is contraindicated in patients with a history of hypersensitivity to any
component of AMCHEPRY. Clinical studies have not been conducted in pediatric
patients, and there is no clinical experience with the use of AMCHEPRY in elderly
patients over 70 years of age. Although no specific disease stage requirements are explicitly defined in the prescribing information, AMCHEPRY has been granted
conditional and time-limited approval in Japan. Accordingly, we plan to continue
collecting efficacy and safety data, with priority placed on the ongoing post-marketing approval condition assessment study (Phase 4).
This was said by the source in Japanese multinational pharmaceutical company Sumitomo Pharma Co., Ltd., in an exclusive statement with CE Report.
In the Japanese Phase 1/2 investigator-initiated clinical study, the major adverse drug reactions reported were muscle tension and dystonia, each occurring in 14.3% of patients. Because AMCHEPRY is a regenerative medical product, the prescribing information indicates the potential for abnormal graft overgrowth and tumorigenicity as theoretical risks. Regular port-transplant monitoring, including MRI examinations, is therefore required. To date, however, no abnormal graft overgrowth, tumorigenicity, or inflammatory findings associated with immune reactions have been observed through 24 months after transplantation in clinical studies.
In the Japanese Phase 1/2 investigator-initiated clinical study, motor symptoms
were evaluated using the MDS-UPDRS Part III total score under conditions in
which antiparkinsonian medications had been withheld for a specified period.
Among the six patients included in the efficacy analysis set, the MDS-UPDRS Part
III total score showed a mean improvement of 9.5 points from baseline at 24
months after transplantation. In addition, MRI and PET assessments indicated
engraftment of the transplanted cells in all six patients at both 12 and 24 months
after transplantation. However, the clinical data available to date remain limited, and AMCHEPRY is currently in the stage of collecting additional data under Japan’s conditional and time-limited approval system. Because the timing and extent of symptom improvement may vary among individual patients, it is not possible to provide a general estimate regarding when clinical improvement can be expected.
Japan’s conditional and time-limited approval system is designed to provide
patients with earlier access to promising therapies once a certain level of efficacy
and safety has been demonstrated, while requiring the collection of additional
clinical data after approval to further evaluate efficacy and safety. The results of
these post-approval studies are subsequently evaluated to determine whether
standard approval should be granted. For AMCHEPRY, the duration of the approval under this framework is seven years. The key difference from standard marketing approval is that additional efficacy and safety data must continue to be collected after approval, and a subsequent application for standard marketing approval must be submitted based on those data. Although the Japanese Phase 1/2 investigator-initiated clinical study provided evidence supporting the efficacy and safety of AMCHEPRY, the number of treated patients was limited. Therefore, continued data collection following marketing approval is a condition of approval. To obtain standard approval, we plan to collect additional efficacy and safety data through a post-marketing approval condition assessment study (Phase 4) and post-marketing surveillance, and to submit an application for standard approval based on the results of those studies.
Sumitomo Pharma's current priority is to advance the post-marketing approval condition assessment study (Phase 4) and continue accumulating additional data regarding the efficacy and safety of AMCHEPRY. Following completion of patient enrollment in the post-marketing approval condition assessment study (Phase 4), treatment outside the post-marketing clinical study is currently expected to begin. However, the timing of such expansion will depend on the progress of the study and therefore has not yet been determined. At present, the company is not in a position to provide information regarding treatment access for foreign patients who do not reside in Japan. With respect to global development, Sumitomo Pharma's current focus is on Japan and the United States. In the longer term, the company is also considering expansion into other regions, including Europe and Asia. However, the timing of regulatory approvals and specific commercialization plans in those regions have not yet been determined.
Photo: Sumitomo Pharma Co., Ltd.
This interview was prepared by Julian Müller
