Diamyd Medical AB, Swedish biotech company focusing on the development of pharmaceuticals for the treatment of pain, neuropathy and diabetes has reported that a phase II study evaluating its drug candidate NP2 Enkephalin did not meet its primary objective of reducing pain in subjects with severe intractable cancer pain. The treatment was however well tolerated, confirming the safety of the company's NTDDS technology.
The purpose of the randomized, double-blind, and placebo-controlled phase II study is to evaluate the effect of intradermal injection of NP2 Enkephalin on pain reported by subjects suffering from severe intractable pain due to cancer, as well as to confirm the safety of the treatment. The study includes a total of 33 adult subjects, 17 randomized to receive NP2 Enkephalin and 16 randomized to the placebo group. It is being conducted at 18 clinics in the United States. It is the first placebo-controlled clinical trial of a drug candidate based on Diamyd Medical's patented Nerve Targeting Drug Delivery System (NTDDS), a gene based technology for delivery of therapeutics directly to the nervous system.
An initial analysis of the results from the 28 day double-blind main study period shows that during day three to 14 following a single dose of study drug, the group that received NP2 Enkephalin reported on average no better improvement in pain score than the placebo treated group. Pain scores are reported daily by the study subjects applying a numerical rating scale from 0 to 10. The treatment has been well tolerated, as demonstrated by a comparable number of serious adverse events in the two treatment groups, and the fact that no serious adverse events have been deemed related to the treatment. Data continues to be collected from an open label extension period of the study where subjects have received up to two additional doses of NP2 Enkephalin. All the subjects also receive conventional pain therapy throughout the study, including opiate drugs.
Although we had hoped for a better outcome regarding pain relief in this study, we note that the treatment appears safe which is an important finding for the whole NTDDS platform, says Peter Zerhouni, president and CEO of Diamyd Medical. We will continue our analysis of this study, including subgroups and the data from the open label extension period, to determine how to adapt the development plan for our NTDDS portfolio of drug candidates addressing diseases and symptoms within the nervous system which today cannot be adequately treated. I would also like to use this opportunity to thank all the study participants as well as the investigators and study staff who dedicate themselves to the conduct of this study.
NP2 Enkephalin is based on the NTDDS platform and delivers the natural painkilling substance enkephalin directly to the nervous system for the treatment of pain. Substantial and sustained pain relief has previously been observed in a clinical phase I study (Fink et al. Annals of Neurology 2011;70:207?212) as well as in numerous preclinical models.
The lack of efficacy in the double-blind part of this study is unexpected given the robust preclinical data and the encouraging results from the previous phase I study with NP2 Enkephalin, says Darren Wolfe, president of Diamyd, Inc., the US subsidiary of Diamyd Medical carrying out the research and development of the NTDDS platform. However, we are still in the early days of exploring the NTDDS technology in man and the concept of nerve targeted gene delivery can remain valid despite failing to demonstrate efficacy in this relatively small trial. Clinical development in intractable pain in subjects with advanced cancer is a challenging indication on many levels. That the technology appears safe in this trial will expand our development options and other indications may prove better targets for this therapeutic approach, be it with NP2 Enkephalin or other drug candidates from our NTDDS platform.
Diamyd Medical's NTDDS is an innovative technology for the delivery of therapeutics directly to the nervous system and forms the basis of the Company's development projects within pain and neuropathy. The NTDDS technology aims to provide a local effect in the parts of the body where the treatment is targeted without affecting the rest of the body.
The NTDDS platform comprises three drug candidates for the treatment of various forms of chronic pain; NP2 Enkephalin, NG2 GAD, NE2 Endomorphin and one drug candidate for the prevention of chemotherapy induced peripheral neuropathy, NN1 Neurotrophin.
Diamyd Medical's NTDDS-based drug candidates consist of a vector which carries a gene for a therapeutic substance, e.g., a painkilling substance. The drug is injected into the skin, where the vector and the gene are taken up by nerve endings and then transported along the body's peripheral nerve pathways to nerve cell bodies that lie just outside the spinal cord. Here the nerve cells own processes are being used to continuously produce the therapeutic substance with the gene as template. Since it is gene-based, a single dose can provide a relatively long-term therapeutic effect that may last several weeks to months. As the treatment acts locally, systemic drug exposure is limited, a fact that may significantly reduce the risk of side effects.
The technology has a wide potential and may be used for the treatment of several different diseases and symptoms in the peripheral and central nervous system such as chronic pain, neuropathy (nerve damage), cancer and neurodegenerative diseases. Research and development on the NTDDS platform is primarily carried out by the subsidiary Diamyd, Inc. located in Pittsburgh, USA.