SA 96 (N-(2-Mercapto-2-Methylpropanoyl)-L-Cysteine) in Rheumatoid Arthritis

Abstract

SA 96 (N-(2-mercapto-2-methylpropanoyl)-L-cysteine) is a new sulfhydryl compound having a relatively similar chemical structure to Tiopronin and D-penicillamine. An open trial of SA 96 treatment (300 mg/day after meals for 16 weeks) was carried out in 11 patients with definite or classical rheumatoid arthritis and with therapeutic failure of previous gold salts and/or D-penicillamine therapy. Two cases were withdrawn from the trial, because of a side effect (hepatitis) in one patient and an unrelated illness in another. The results in the 9 patients completing the trial demonstrated statistically significant improvement in the clinical and laboratory measurements. A marked abatement of disease activity was noted in 5 of 9 patients who did not benefit from, or suffered a relapse during previous chrysotherapy and in 1 of 5 patients without benefit, or with relapse following previous D-penicillamine treatment. Among 4 patients who had discontinued D-penicillamine because of its intolerable cutaneous side effects, 3 patients completed the trial, with favourable results. The results of this trial seem to indicate that SA 96 is possibly of value as a slow-acting antirheumatic drug in some patients with therapeutic failure of gold salts or D-penicillamine.

Bucillamine (a new therapeutic agent for rheumatoid arthritis) induced nephrotic syndrome: a report of two cases and review of the literature

“…Bucillamine (N-[2-mercapto-methylpropanyl]-Lcysteine), was recently developed in Japan as a therapeutic agent for the treatment of rheumatoid arthritis (RA) [5,19]. It is basically a cysteine derivative with two sulfhydryl groups, and its structure bears a striking resemblance to that of D-penicillamine (Fig.…”

Differences in the effects of the antirheumatic drugs, bucillamine andd-penicillamine, on mitogen-induced proliferation of mouse spleen cells

“…In several clinical studies, both bucillamine and D-pen were shown to give the same types of beneficial therapeutic effects in RA patients. Though both compounds seem to affect the disorders of the immune system in RA patients, some differences in response of RA patients have been observed between bucillamine and o-pen, that is, bucillamine showed beneficial effects in some patients who did not respond to o-pen [8]. Such differences in therapeutic responses between bucillamine and D-pen may be correlated with the differences of action of bucillamine and D-pen on lymphocytes as described in this paper.…”

“…For example, ])-pen binds to vitamin B 6 and long term administration of D-pen causes vitamin B 6 deficiency, whereas bucillamine does not have any affinity for vitamin B 6 and intake of bucillamine does not result in vitamin B 6 deficiency [7]. It has also been demonstrated that buciltamine shows beneficial effects in some RA patients who do not respond to D-pen [8]. Therefore, in some aspects, bucillamine seems to have some properties which are not observed with D-pen.…”

Clinical course of bucillamine-induced nephropathy in patients with rheumatoid arthritis

“…Of the patients who develop persistent proteinuria, membranous nephropathy is reported to be seen in 70% or 88% during treatment with gold 4 or D-penicillamine, 5 respectively. Bucillamine (BCL; N-[2-mercapto-2-methypropinil]-lcysteine), a DMARD widely prescribed in Japan, has a chemical structure similar that of to D-penicillamine, 7,8 and is also reported to be a cause of membranous nephropathy. [9][10][11] However, current knowledge of the nephropathy associated with the use of BCL is limited, and, to our knowledge, the clinical course of the nephropathy has not been described in detail.…”