Rapport Shares Jump More Than 50% After Successful Acute Mania Trial
Key Facts
Shares of Rapport Therapeutics jumped more than 50% in premarket trading on 20 October 2026 after the company announced positive trial results for the treatment of acute manic episodes, according to Investing.com. The company said its drug candidate RAP-219 met the trial's primary endpoint, as well as the prespecified secondary endpoint assessing mania severity. The Phase Two study enrolled 253 adults experiencing acute manic episodes associated with bipolar I disorder. Participants received either the experimental treatment at a daily dose of 0.75 mg or a placebo to compare the two groups. The treatment period lasted 3 weeks and took place in hospital, according to trial details Investing.com cited from the company. The reported results concern the treatment of acute manic episodes in this patient population.
According to Rapport's filing with the U.S. Securities and Exchange Commission, the placebo-adjusted improvement was 3.1 points on the Young Mania Rating Scale. The company measured this difference at week three, the scheduled assessment point for the primary endpoint after treatment began. The associated p-value was 0.045, according to the filing, which reported the least-squares mean improvement. On the Clinical Global Impression–Bipolar Severity of Mania scale, the treatment showed a difference of 0.4 points versus placebo. This measure was the trial's prespecified secondary endpoint, according to the press release attached to the company's regulatory filing. The p-value for that endpoint was 0.024 at the end of the treatment period.
On safety, Rapport said in its results statement that "all treatment-emergent adverse events were mild or moderate in severity." Tolerability was assessed in the study, in which participants received treatment or placebo during their hospital stay. Before the results were announced, company management had presented its therapeutic approach at a TD Cowen conference, according to Investing.com's coverage of the presentation. Management described the approach as dopamine-independent and linked it to the potential for a different tolerability profile in patients. It said this potential difference included comparisons with current treatments used for bipolar disorder and with antiseizure treatments, an assessment management offered regarding the characteristics of its drug approach.
Before the results, Truist had offered a cautious assessment of the trial, describing it as an exploratory proof-of-concept study in acute mania. In an assessment reported by Investing.com before the data were released, the firm noted limited evidence supporting the underlying therapeutic mechanism in this use. Its reservations also covered the dosing regimen selected for the study in acute manic episodes, alongside the mechanism underlying the treatment. In another earlier assessment, Raymond James raised its price target for Rapport shares to $75 from $68. The firm made the adjustment on 17 August 2026 while maintaining its "Strong Buy" rating on the stock, ahead of the mania trial results.
The stock had come under pressure in the period before the results, falling 17.6% in afternoon trading on 23 September 2026. That decline followed management's appearance at a TD Cowen conference, according to Investing.com, while the mania trial data were still pending. On the financial front, the company reported a balance of $436.1 million at the end of June 2026, according to its investor presentation attached to its regulatory filing. The balance comprises cash, cash equivalents and short-term investments, excluding restricted cash from the total. Rapport said in the presentation that this balance, recorded on 30 June, was expected to fund its operations into the second half of 2029.
Rapport identified its next step as advancing to two Phase Three trials for acute mania associated with bipolar disorder. The company expects to begin the trials in the second half of 2027, according to Investing.com's account of its development plan. The planned trials follow the reported Phase Two study, which tested the drug candidate in adults experiencing acute manic episodes. The upcoming program targets the same therapeutic use for which the company presented results, as part of its plan to complete development of the drug candidate for this disorder. Rapport identified the second half of 2027 as the expected start date for the upcoming trials under its announced development timetable for treating acute manic episodes.