Rein Therapeutics (RNTX) Risk Analysis

We may experience difficulties in patient enrollment in our clinical trials for a variety of reasons. The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the trial until its conclusion. The enrollment of patients depends on many factors, including, but not limited to: - the patient eligibility and exclusion criteria defined in the protocol;- the size of the patient population required for analysis of the trial's primary endpoints and the process for identifying patients;- the willingness or availability of patients to participate in our trials;- the proximity of patients to trial sites;- the design of the trial;- our ability to recruit clinical trial investigators with the appropriate competencies and experience;- clinicians' and patients' perceptions as to the potential advantages and risks of the product candidate being studied in relation to other available therapies, including any new products that may be approved for the indications we are investigating;- the availability of competing commercially available therapies and other competing product candidates' clinical trials;- our ability to obtain and maintain patient informed consents; and - the risk that patients enrolled in clinical trials will drop out of the trials or are discontinued from trials at the recommendation of the principal investigator before completion. For example, we are developing LTI-03 for the treatment of IPF, which is an orphan indication. In the U.S., IPF is estimated to affect approximately 100,000 people. As a result, we may encounter difficulties enrolling subjects in our clinical trials of LTI-03 due, in part, to the small size of this patient population. In addition, our clinical trials could compete with other clinical trials for product candidates that are in the same therapeutic areas as our product candidates, and this competition will reduce the number and types of patients available to us, because some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. Since the number of qualified clinical investigators is limited, it is possible that we would conduct some of our clinical trials at the same clinical trial sites that a competitor uses, which would reduce the number of patients who are available for our clinical trials in such clinical trial site. Certain of our planned clinical trials may also involve invasive procedures such as bronchoscopy and broncho-alveolar lavage procedure, which may lead some patients to drop out of trials to avoid these follow-up procedures. In addition, patients participating in our clinical trials may drop out before completion of the trial or experience adverse medical events unrelated to our products.

To obtain the requisite regulatory approvals to commercialize any product candidates, we must demonstrate through extensive preclinical studies and clinical trials that our product candidates are safe and effective in humans. Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. In particular, the general approach for the FDA approval of a new drug is dispositive data from two well-controlled, Phase 3 clinical trials of the relevant drug in the relevant patient population. Phase 3 clinical trials typically involve many patients, have significant costs and can take years to complete. A product candidate can fail at any stage of testing, even after observing promising signals of activity in earlier preclinical studies or clinical trials. The results of preclinical studies and early clinical trials of our product candidates may not be predictive of the results of later-stage clinical trials. In addition, initial success in clinical trials may not be indicative of results obtained when such trials are completed. There is typically an extremely high rate of attrition of candidate therapies from failure of these candidates proceeding through clinical trials. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy profile despite having progressed through preclinical studies and previous clinical trials. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or unacceptable safety issues, notwithstanding promising results in earlier trials. Most product candidates that commence clinical trials are never approved as new drugs and there can be no assurance that any of our future clinical trials will ultimately be successful or support further clinical development of LTI-03. Product candidates that appear promising in the early phases of development may fail to reach the market for several reasons, including, but not limited to: - clinical trials or preclinical studies may show the product candidates to be less effective than expected (e.g., a clinical trial could fail to meet its primary endpoint(s)) or to have unacceptable side effects or toxicities;- failure to establish clinical endpoints that applicable regulatory authorities would consider clinically meaningful;- failure to receive the necessary regulatory approvals;- failure of contract manufacturers to comply with regulatory requirements;- manufacturing costs, formulation issues, pricing or reimbursement issues, or other factors that make a product candidate uneconomical; and - the proprietary rights of others and their competing products and technologies that may prevent one of our product candidates from being commercialized. In addition, differences in trial design between early-stage clinical trials and later-stage clinical trials make it difficult to extrapolate the results of earlier clinical trials to later clinical trials. Moreover, clinical data are often susceptible to varying interpretations and analyses, and many candidates that have performed satisfactorily in clinical trials have nonetheless failed to obtain marketing approval of their products. Some of our future trials may be open label studies, where both the patient and investigator know whether a patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most typically, open label clinical trials test only the investigational product candidates and sometimes do so at different dose levels. Open label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open label clinical trials are aware when they are receiving treatment. In addition, open label clinical trials may be subject to an "investigator bias" where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. Therefore, it is possible that positive results observed in open label trials will not be replicated in later placebo-controlled trials. In addition, the standards that the FDA and comparable foreign regulatory authorities use when regulating us require judgment and can change, which makes it difficult to predict with certainty how they will be applied. Any analysis we perform of data from preclinical and clinical activities is subject to confirmation and interpretation by regulatory authorities, which could delay, limit or prevent regulatory approval. We may also encounter unexpected delays or increased costs due to new government regulations. Examples of such regulations include future legislation or administrative action, or changes in the FDA policy during the period of product development and the FDA regulatory review. It is impossible to predict whether legislative changes will be enacted, or whether the FDA or foreign regulations, guidance or interpretations will be changed, or what the impact of such changes, if any, may be. The FDA also requires a panel of experts, referred to as an Advisory Committee, to deliberate on the adequacy of the safety and efficacy data to support product candidate approval. The opinion of the Advisory Committee, although not binding, may have a significant impact on our ability to obtain approval of any product candidates that we develop. If we seek to conduct clinical trials in foreign countries or pursue marketing approvals in foreign jurisdictions, we must comply with numerous foreign regulatory requirements governing, among other things, the ethical conduct of clinical trials, manufacturing and marketing authorization, pricing and third-party reimbursement. The foreign regulatory approval process varies among countries and may include all of the risks associated with FDA approval described above as well as risks attributable to the satisfaction of local regulations in foreign jurisdictions. Moreover, the time required to obtain approval may differ from that required to obtain FDA approval. Approval by the FDA does not ensure approval by regulatory authorities outside the U.S. and vice versa. Successful completion of clinical trials is a prerequisite to submitting a marketing application to the FDA and similar marketing applications to comparable foreign regulatory authorities, for each product candidate and, consequently, the ultimate approval and commercial marketing of any product candidates. We may experience negative or inconclusive results, which may result in our deciding, or our being required by regulators, to conduct additional clinical studies or trials or abandon some or all of our product development programs, which could have a material adverse effect on our business. Studies involving human tissue samples may also be subject to institutional and government human subject privacy policies that may vary by territory. We or our partners which use human tissue samples or conduct tissue and/or animal studies on our behalf, may be found to be in violation of one or more of these regulations or policies and may be subject to closure, censure or other penalties. In some cases, these penalties could materially impact the performance, availability, or validity of studies conducted by us or on our behalf. Even in the absence of violations resulting in penalties, regulatory and other authorities may refuse to authorize the conduct or to accept the results of studies for regulatory or ethical reasons.

We completed a healthy normal volunteer Phase 1a clinical trial of our clinical product candidate LTI-03. During our LTI-03 Phase 1a clinical trial, subjects experienced mild Treatment Emergent Adverse Events, or TEAEs, such as dry cough, as well as moderate or even severe TEAEs, such as wheezing, chest tightness, or decline in the amount of air a person can force from their lungs in one second. While no subject experienced a Serious Adverse Event, or SAE, it is possible that subjects in future clinical studies could develop TEAEs such as the ones experienced in the Phase 1a clinical trial, and it is possible that such the number and/or severity of such TEAEs could result in a pause or cessation of the clinical trial. We have also completed Phase 1b and Phase 2a clinical trials of our clinical product candidate LTI-01 in LPE patients. In the Phase 2a trial, four subjects experienced TEAEs, including 1 mild, 2 moderate, and 1 severe TEAE. There were no SAEs reported. The product candidate was concluded to be generally well-tolerated across all doses in trial participants. If significant adverse events or other side effects are observed in any of our ongoing or future clinical trials, whether or not related to our product candidates, we may have difficulty recruiting patients to our clinical trials, patients may drop out of our trials, or we may be required to abandon the trials or our development efforts altogether or may result in safety profile that could delay or prevent regulatory approval or market acceptance of any of our product candidates.

We may experience delays in initiating or completing clinical trials. We also may experience numerous unforeseen events during, or as a result of, any future clinical trials that could delay or prevent our ability to receive marketing approval or commercialize LTI-03, including, but not limited to: - regulators or institutional review boards, or IRBs, or ethics committees may not authorize us or our investigators to commence a clinical trial or conduct a clinical trial at a prospective trial site;- the FDA or other comparable regulatory authorities may disagree with our clinical trial design, including with respect to dosing levels administered in our planned clinical trials, which may delay or prevent us from initiating our clinical trials with our originally intended trial design;- we may experience delays in reaching, or we may fail to reach, agreement on acceptable terms with prospective trial sites and prospective contract research organizations, or CROs, which can be subject to extensive negotiation and may vary significantly among different CROs and trial sites;- the number of subjects required for clinical trials of any product candidates may be larger than we anticipate or patient recruitment and enrollment may be slow or subjects may drop out of these clinical trials or fail to return for post-treatment follow-up at a higher rate than we anticipate;- our third-party contractors may fail to comply with regulatory requirements or meet their contractual obligations to us in a timely manner, or at all, or may deviate from the clinical trial protocol or drop out of the trial, which may require that we add new clinical trial sites or investigators;- additional delays and interruptions to our clinical trials could extend the duration of the trials and increase the overall costs to finish the trials as our fixed costs are not substantially reduced during delays;- we may elect to, or regulators, IRBs, Data Safety Monitoring Boards, or DSMBs, or ethics committees may require that we or our investigators, suspend or terminate clinical research or trials for various reasons, including noncompliance with regulatory requirements or a finding that the participants are being exposed to unacceptable health risks;- we may not have the financial resources available to begin and complete the planned trials, or the cost of clinical trials of any product candidates may be greater than we anticipate;- the supply or quality of our product candidates or other materials necessary to conduct clinical trials of our product candidates may be insufficient or inadequate to initiate or complete a given clinical trial; and - the FDA or other comparable foreign regulatory authorities may require us to submit additional data such as long-term toxicology studies or impose other requirements before permitting us to initiate a clinical trial. Our product development costs will increase if we experience additional delays in clinical testing or in obtaining marketing approvals. We do not know whether any of our clinical trials will begin as planned, will need to be restructured or will be completed on schedule, or at all. For example, we previously announced that we expect to investigate LTI-01 in an additional Phase 2 clinical trial. However, in June 2024, we decided to temporarily delay clinical development of LTI-01 in an effort to focus our resources on clinical development of LTI-03 and until additional funds are raised. In the fourth quarter of 2024, we determined that the temporary delay of further clinical development of LTI-01 may not be a short-term measure. In the fourth quarter of 2025, we decided to pause development activities related to LTI-01 for an indefinite period due to our current capital limitations. If we do not achieve our product development goals in the time frames we announce and expect, the approval and commercialization of our product candidates may be delayed or prevented entirely. Significant clinical trial delays also could shorten any periods during which we may have the exclusive right to commercialize our product candidates and may allow our competitors to bring products to market before we do, potentially impairing our ability to successfully commercialize our product candidates and harming our business and results of operations. Any delays in our clinical development programs may harm our business, financial condition and results of operations significantly.

We may in the future choose to conduct one or more clinical trials outside the U.S. The acceptance of study data from clinical trials conducted outside the U.S. or another jurisdiction by the FDA or comparable foreign regulatory authority may be subject to certain conditions or may not be accepted at all. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the U.S. or the applicable jurisdiction. If the FDA or any comparable foreign regulatory authority does not accept such data, it would result in the need for additional trials, which could be costly and time-consuming, and which may result in current or future product candidates that we may develop being delayed for development or regulatory authorization or not receiving approval for commercialization in the applicable jurisdiction.

We currently have no products approved for sale and we cannot guarantee that we will ever have marketable products. Clinical failure can occur at any stage of clinical development. Clinical trials may produce negative or inconclusive results, and we or any future collaborators may decide, or regulatory authorities may require us, to conduct additional clinical trials or nonclinical studies. We will be required to demonstrate with substantial evidence through well-controlled, adequate clinical trials that our product candidates are safe and effective for use in a diverse population before we can seek marketing approvals for their commercial sale. Success in preclinical studies and early-stage clinical trials does not mean that future larger registration clinical trials will be successful. This is because product candidates in later-stage clinical trials may fail to demonstrate sufficient safety and efficacy to the satisfaction of the FDA and comparable foreign regulatory authorities despite having progressed through nonclinical studies and early-stage clinical trials. From time to time, we may publish or report topline, interim or preliminary data from our clinical trials. We make assumptions, estimates, calculations, and conclusions as part of our analyses of data, and we may not have received or had the opportunity to evaluate all data fully and carefully. As a result, topline, interim or preliminary data from clinical trials that we may conduct may not be indicative of the final results of such trials and are subject to the risk that one or more of the clinical outcomes may materially change as subject enrollment continues and more data from the trials become available. Topline, interim or preliminary data also remain subject to audit and verification procedures that may result in the final data being materially different from the interim or preliminary data. As a result, topline, interim or preliminary data should be viewed with caution until the final data are available.

Our approach is to develop targeted treatments for fibrosis with an initial focus on Cav1 biology and utilization of its caveolin scaffolding domain, or CSD, peptide region. However, to date, this mechanism has not been definitively proven to successfully treat fibrosis in patients. Utilizing a Cav1-related peptide to treat fibrosis is a novel approach in a rapidly developing field, and there can be no assurance that we will not experience unforeseen problems or delays in developing our product candidates, that such problems or delays will not result in unanticipated costs, or that any such development problems can be solved. Therefore, we may ultimately discover that our approach and any product candidates resulting therefrom do not possess properties required for therapeutic effectiveness. As a result, we may never succeed in developing a marketable product. In addition, while we have utilized cell assays, precision cut lung slice models, and in vivo animal models to assess both anti-fibrotic and epithelium preservation functions of Cav1-related peptides, there can be no assurance that our technology will yield its intended benefits in human patients.